Back before we had kids and I could afford to put gas in a boat I pulled the perfectly fine 350 small block and put a 383 stoker kit in. My wife was not pleased, I was very pleased with the end result.
HUGE NOTE TO ADD. The starter, alternator, carb overflows were different than a truck or cars. They are supposed to be marine grade so there’s no open spark risk. The carb needs to have the jhook on the overflow in the event your floats stick open. Insurance used to cancel claims due to inspection’s showing non marine parts were used
I dont mean to be rude, but if you're stupid enough to put a non marine part on a boat, you deserve what happens. Ngl, they actually recommend using marine plywood over treated osb in a lot of scenarios.
As these engines get older internal scale will form that often plugs up the block drains and manifold drains. Use a small screw driver to poke into the opened petcocks to ensure all the water comes out. On the later models with connected hoses to a single drain remove the quick connect hose connection on each side of the block and insert a small screw driver to move the scale and allow the water to fully drain. I learned this the hard way and was told how by seasoned marina mechanic what I needed to do in the future.
@@alexandermckay8594you can remove hoses an add coolant to them and it will either flush out water by replacing it or dilute the water enough to not freeze.
@@workingcountry1776 run muffs from a Rubbermaid container full of the coolant. Put another Rubbermaid under the prop and run the engine until the water turns the color of the coolant. There are videos on TH-cam here but I've never done it yet.
Brings a smile to my face to see some marine content on the channel! Mercuiser didn't continue on with the LS line of engines but volvo penta did. Took a long time but all modern gasoline I/O's are running catalysts as well now. Albeit they are falling by the wayside of the simplicity, servicability and reliability of modern outboard engines . Im sure youve got a good marine contact near by you but if you ever have any questions dont hesitate to reach out - northern ontario based marine tech of 14 years 👍
I had an old wakasha/ford 302 in a boat. I put a thermostat in it. Got a little better efficiency, but more importantly I got hot water to put in the wetsuit before jumping into the 5 degree Celsius lake.
That was awesome! Im a retired disabled MERCRUISER mechanic, you brought me back to the shop! You covered basically everything! The one thing I'd brought up is the "CORROSION SPAYS?" And fuel stabilers, thank you for the journey back to the best years of my life. Nice shop! I'd bet alot of dreams came threw there. Keep up the keeping up!!
Usually, it's the oil pressure sensor that will rust away, allowing all the oil to leave the engine. I seen some really bad oil pans on these mercs, but never rusted thru. If the engine were that bad, it wouldn't be in running condition anyway. A starter will rust solid, long before an oil pan will. 😂 plus, the 4.3 oil pans are cast alum, instead of tin. And have plastic timing covers that are embossed with: replace if removed.
30 plus years ago i did enjoy being on my friends boat powered by the GM 4 cyl Iron duke. It could pull 2 skiers and would run all day on 20 gals of fuel and was quiet
@brandonlarry1645 nope I left the Blazer oil pan on it. I did switch dipsticks, so you need to fill your engine up with the correct amount of oil, then calibrate the boat dipstick to read correctly with the new pan.
Been on the same 350 Merc for 30 years... Thousands of hours, all original right down to the plugs and wires for over 25 years. The only problem we ever had was the raw water pump and finally a hairline crack in one of the cylinder heads. Just goes to show if you take care of it it'll take care of you.
@windward2818 Both. Port is brackish, about 5 miles inland, occasional trips upriver, but most weekends are spent in the salt. Don't ask me why or how it's been so tough, but never would I trade for another boat or motor. The Bravo III, on the other hand... Number 3 was rebuilt, the lower unit was replaced the following season, and this will be the third season on number 4. If they don't pit themselves to death, they just self-destruct.
@@dozerfarms My boat is 24 years old and like yours I'm still on the original engine, original starter, carb, alternator, everything. Thousands of hours and she still runs strong! I replace the water pump every other year, and all the fluids get changed yearly. 100% salt water use and the boat gets winterized every year by me. Sounds like you know how to take care of a boat and its engine. These are great motors. She'll still hit 50 mph on plane...
@jamess3532 Haha yessir! I do everything myself that doesn't require a special tool to do. Last weekend was waxing and waterproofing the canvas, the week before was the bottompaint, anodes, and outdrive oil, all I have left is to throw the rest of my stuff on board, hook up my instruments, and drop her in. Here's to a great 2024 season! 🍻
@@dozerfarms I'm prepping mine for the season too. It will be a few weeks before she gets in the water though since I decided to replace the flooring in the cockpit. She was getting a little soft around the engine shroud. Just my opinion here, but learning how to maintain your own boat is paramount to getting the most out of it. I think a lot of folks purchase boats without learning what it takes to properly maintain them. If you do everything yourself you know it was done right. Happy boating.
I worked on these for over 10 years and was certified on Mercury outboards and Mercrusiers . Went to merc school in Dallas. In school we were told the only internal parts that were changed from the GM engine was the camshaft that made its power mainly in low to midrange around 4200 rpm’s. And installed Stainless steel valves.
You did an excellent explanation of the mechanical differences between automotive and marine engines. But you forgot an crucial difference, the electrical system. The electrical systems for marine application, not only the engine, is different than automotive. The engine bay of a car is very well ventilated, you can see the ground when you open the hood. For a boat, when you open the engine bay of an inboard like yours, you see a solid sealed (hopefully) hull. There is nowhere for the gas fumes to go. This is the main reason for activating the venting fans before starting your engine. The electrical system of a marine engine is specially designed to avoid the electrical arcs of the various form of switches to be in direct contact with the surrounding air. Even the wires are different, each braid is individually tinned to prevent corrosion. Never use a car alternator, marine grade alternator will have double insulation to prevent shock and sparks. Rich, be careful with the LS swap, use marine grade electrical system.
That definitely gives me a higher appreciation of what Mercruiser has done with these engines. It is great to see how you speak directly to us backyard mechanics.
He mentioned draining the blocks for the winter layup. Don't forget to run pink biodegradable Antifreeze through the engine via the raw water pickup. Either do it while the engine is hot or remove the thermostat and run. Run until you get solid pink coming out the exhaust. You will not crack a block that way. 4.3s love to crack behind the exhaust manifold.
I was using the cheap pink stuff from Walmart then I realized you need the more expensive stuff rated for engines. The cheap stuff is alcohol based and not good. The expensive stuff has propylene glycol.
@@joesilverbliss1721 You want to keep using the cheap stuff and drain it out after you run 5 gallons through the engine. The procedure is simple: Use a 5 gallon bucket with a spigot on the bottom that you can connect a short garden hose to and run it to your muffs. Run the engine until the thermostat is open using water and then switch to the coolant and run it until your 5 gallon bucket is empty. I collect most of it and store it back in the jugs for the following year. Pull your blue drain plugs and your done. Do not use radiator coolant rated for automobiles. Lots of youtube videos showing various methods....
We mainly use the pink for the water systems in the cabin. It's much cheaper to just drain out the water from the engine. Draining all the water from the water system is much more difficult.
@@thediplomasta5891 As long as you can guarantee that there is absolutely no water left in your engine cooling system than you can get away with not running the antifreeze through it. Peace of mind and extra assurance is why the majority of us flush with RV antifreeze. Especially for those of us who live in extremely cold places where temps will stay below zero for a week straight, or longer. That way there if any residual water is trapped it's at least displaced with the antifreeze and won't crack your engine block. Like I said, I collect it all in a bin placed under the stern drive and put it back in the jugs for the following year. It hardly costs anything doing it this way and it's a lot cheaper than having to replace an engine block! I know some people use JB weld to fix cracks but that's not a real fix.
4 bolt main GM blocks have not been used in the production marine world since the early 80s. Brass freeze (core) plugs and different camshaft are main differences between automotive & marine blocks sourced from GM. I look forward to your LS swap series. Keep up the good work.
My family has a '92 Mercruiser 4.3l. When winterizing, we drain everything then add a little plumbers antifreeze to the exhaust manifolds. We found the drain on the exhaust manifolds isn't truly at the low spot and ended up with a little water pooled at the back. We got lucky and were able to get the manifold repaired but now we always add a little antifreeze just to be safe.
I work on boats on the coast I/O boats have fallen out of style to much headache. Outboards are taking over for the smaller sized boats. They were designed to be on a boat right from the start. They hold up well and in my opinion much easier and enjoyable to work on.
Agreed. And the new 4 stroke OB’s are so quiet now. You can barely hear them idle except for bubbles from the exhaust. I have ‘06 Merc 150 EFI 2 stroke that’s fuel/oil injected and it’s loud. Sounds cool when you run it in the driveway with water muffs on it though.
My Volvo Penta 305 required very little maintenance for 15 years (oil and filter changes and draining the block every winter) until sand blocked one of the drains and cracked the block. Still ran great but a bit of a leak problem. I bought a 380 hp 350 for $3500 and swapped computers for the fuel injection. Runs great, a 380 hp outboard would probably run 30k! I'm glad I got a inboard. I'm sure your "small" boat is much bigger than my boat LoL I wouldn't take mine on the ocean.
I have a truck engine in my boat. It's a 1995 Bayliner. I pulled the original 4.3 engine because it was not winterized and then compared both engines while putting on all new gaskets on the truck engine. They were identical except for the camshaft which I did not check and did not know that there may be a difference in camshafts at the time.
@@brandonlarry1645 My 4.3 from my boat was 1995, and the replacement engine came from a 2002 S10 truck. I kept the truck oil pan because the pickup tubes were different, so the oil pan from 1995 did not work on the 2002. I had to modify the oil dipstick a bit for it to work, considering that the dipstick had to be from the same oil pan. I had to use the water pump from 1995 because of the v belt pulleys. The pump did fit, but the timing cover did not work for that water pump. I had to modify one of the bolts (make a flat head) so that the pump would fit. What year is your boat/engine?
Thank you so much for pointing out the difference between marine and automotive cams. You have no idea how many calls i get during lake season down here in Nevada when people hydo lock their brand-new motor first go out. Also down here we usually just get a big bucket and fill it with coolant drop the outdrive in and run it for a few minutes. Never had a problem, our 21-foot sleekcraft has had the same motor since 1996 and it still runs, we don't know how its honestly insane. Its a Merc alpha 260hp 350 sbc thing is a champ.
Look out for sand/silt build up in your engine block. This affects the cooling, but it also can trap water that won’t drain when you open the plugs to winterize (ask me how I know). Pull the drain plugs completely and use a piece of stiff wire to clean out the drain passages as best you can. I then fill the block with rv anti freeze through the thermostat housing and let it run out the drain holes.
Back in the 90's I worked at a local marina. We did hundreds of winter/summerizations on boats and had large storage buildings for winter. I think I still have fiberglass shards in my forearms from reaching around the larger engines stuffed into the fiberglass boats. We (the young mechanics and helpers) always preferred to work on the Mercruiser stuff, and specifically the Cobalts. They were simply a better built and better engineered pleasure boat than any of the others at the time. Bayliner and Maxim were always the worst. We called them the "Kraco" of the boating world.
Great video. Mine is a 1999 Crown Line 23 ft 5.7 carbed. Bravo 3 (I think, 2 props) out drive, Fast boat and I have it professionally serviced twice a year, fall and spring. I think I am doing it right as I have no time to work on my boat myself but love it. Not a lot of hours but 100% good and reliable. Always kept inside and a great boat for lake Pend Oreille, 1600 ft deep!!!
I do everything you mentioned in the video, in addition I warm up the engines using the muffs until the thermostat opens then switch over from the hose to a bucket of anti freeze. Once the antifreeze comes out the exhaust I then fog the engine until it stalls out. Once it stall out I open the drains in the manifolds and the block. So far so good.
Good vid, Matt. When I worked at a marina, the running joke was the difference in most parts was a coat of "phantom black" (Mercury's black paint name) and the quadrupling of list price, although that isn't _really_ true.......
As a 10 year mercruiser tech and a long time follower of your channel i thought for sure I’d see this video and see something you may not have, but your good! That being said if you need a random part we’ve got a hoard of mercruiser parts at our Maryland shop! Awesome video
I think he had the cylinder head info backwards between the two engines. I would definitely use the 305 heads on the carb’d 350 engine. A 305 head usually has a much smaller combustion chamber and would raise the comp. ratio a great deal. I would transfer all the top end from the FI engine and stick on the carb’d 350 block. Run premium gas and hit the lake. 0:03
@@Ddabsolve if you go back and look, his 350 carb’d engine is an ‘87 model. 305 Vortec heads would not make that engine a dog, plus he could use all the stock EFI from the original boat engine. 305 Vortec heads do not flow as well as the 350 Vortecs but they flow fairly decent, and prolly better than the ones that are on the carb’d 350.
WOW, thank you sir. Exceptional content here. Honestly, anyone who isn't able or doesn't watch this video before buying a used boat with a Mercruiser is missing out. OMG, I can tell you've saved me thousands of dollars with a 15 minute investment. I cannot thank you enough. Subscribed. Liked.
Having built a truck engine for a boat that cracked. I noted the intake gaskets were different and a side by side comparison showed the head gaskets had way smaller passages for coolant flow on the boat motor. I would guess due to them running colder in a boat.
Go and have a look at B is for Build. He swapped from twin v8 Cummins to twin high performance LS motors. It's like a slow motion train wreck. The original engines weren't Cummins best effort, but he killed one by not checking the oil, which it was burning fast.
@@mz22wa The original engines were 14 liter 419hp Cummins VT903Ms. He could have got another for around $10k. There are QSB6.7s that would beat the 903 power for a time. The 'government' rating on the 6.7s will go to 550hp. But continuous rating is 305hp. CAT C12 ACERT 12l diesels will run about 700hp for $40k. 500hp Yanmar diesels are about $25k each. Yanmar 6LT640 640hp marine diesels are $35k and would probably have worked too.
I think B (Chris?) has said he doesn't have much experience with diesels but lots with LS. I would have stuck with diesels too but the converrsion is more challenging & prob makes for better content. To be honest, i would have sold the boat instead of dealing with the blown engine!
Running in saltwater it is a glycol based coolant with heat exchanger. More complex with raw water pumps and heat exchangers but when maintained, more reliable to my mind.
Great content- thanks for posting. I’ve spent hundreds of hours hanging upside down in I/O engine bays scraping arms and knuckles while winterizing. It was a nice change to switch to outboard power and be able to just stand beside the motor to work on it as well as having about 95% of the cooling water just self drain every time you turn the motor off. While you are working on the engine swap carefully go over the outdrive, check the rubber driveshaft and shift cable bellows for aging, wear, cracking and leaks. Sinking a boat that way ain’t no fun at all..
I've put several junkyard 4.3s in boats. Only difference I ever found d was the cams. Swapped the marine cams in and away they went. Lots of happy customers
My buddy is a commercial crabber and he had a 5.7 mercrusier in one of his older boats. To insure he didnt crack the block/manifolds in the winter. When he winterized the boat, he would flush it with fresh water using the muffs and garden hose. Then right before he would fog the engine he would mix 2 jugs of straight antifreeze and water in a 5 gallon bucket. He would then stick a sump pump into the bucket to help pump the mix into his flush muffs. He would run the engine until he had his special mixture running out the exhaust. I guess it was easier doing it that way then trying to drain the water out the correct way.
@@conrasm I would be concerned that this "pink" antifreeze is not formulated for automotive engines as is engine antifreeze, therefore I would not use it personally.
No matter what slight issues they may have. There is not an outboard motor that sounds as good going across the lake at 4 grand. This is my humble opinion. I have a 2016 383 stroker in my 23-foot offshore boat. I live in florida and don't have to worry much about winterizing the engine. I pull it out every couple years and let machine shop go through it. Love it. Sounds awesome.
"I'd never swap from Diesel to Gas." First thought - follows B is for Build 🤣 At least Chris' videos are a help in figuring out manifolds and such. I am actually happy to see the twin LS engines seem to handle his boat quite well. I will also be curious to see what you end up running for prop once you've got a lot more HP to work with, this should be a really fun boat.
In stead of draining the engine we just had a big tub of antifreeze, ran the outboard in and pumped it in, did that for 5 winters never froze. No issues also stopped the rusting.
Such an informative video. Considering Rich is relatively new to marine, the content is still incredibly well researched. I can’t wait for B-Is for Bodge’s LSX powered boat to spectacularly blow up
Rich you talk about the blocks freezing and describe the drain ports. Although the drain ports work their is actually a much easier way to keep them from freezing. Simply you get a pair of muffs on the lower and pump non toxic antifreeze in then fire the motor up and run it for about 5-10 minutes. According to Merc this will fill the entire raw water side of the cooling system with antifreeze and your good. And as long as u use non tox u don’t have to drain the antifreeze out in the spring.
The secret is to live in a part of the world that doesn't stay frozen for 9 months out of the year. If it never freezes you dont have to winterize! Only fun about the cold is snowmobiling and that gets old quick.
@@DEBOSSGARAGE I am a Texan. You realize I was just kidding and ragging on Y'all Canadians? Every few years we have a freeze and have to actually winterize our boats. The ones that sit outside anyway. It never, ever, gets cold enough to worry about something in a garage.
Firs statement probably the most honest words ever spoken! The owners are the problem. Ive had them unplug hour meters and swear they had not used it since i fixed it. He didnt know i put an hour meter in the engin compartment. Others didnt realise i can hooj up a laptop and see every single second of how you ran your engine! Yup, 2 hours with 6psi oil pressure and 4 at 200f, that pretty much voids your warranty.
My hands down favorite Mercruiser engines are the 165 both the inline six and the four banger. Both very economic and incredibly reliable. My 1976 Merc 165 L6 runs at a religious 143 degrees and only burns about 5-6 gph at 3200 rpm and 26-27 mph. That's its sweet spot and cruising speed. I'm slowly restoring an 18' 1976 Apollo tri hull. With a 15"x17 pitch prop, just me and a full tank of fuel on perfect water she does 41 mph at 4500 rpm WOT. For such a heavy boat it has a pretty good hole shot and is a fantastic boat for tubing.
Many times late in the year I've put eather a space heater or a halogen work lite in the engine bay to keep it warm enough over a unusually cold night. Worth it to get another couple warm boat days inn.
just watched your stuff grea tinfo i just got my 35o back from machine shop after two years and forgot where the knock sensor were its a 2001 350 mpi was hoping to spy on your motors but did not see them great job
I have a 2005 5.0L. Make sure you changes the plugs regularly. When i bought the boat the plugs had never been changed. They were rusted in place and disintegrated. I had to pull the heads to fix that problem. Major pain. All good now. Boat runs great.
Had a military sub engineer today working in a motor shop . He told me to take my knock sensor and put it on the other side of the motor . In its current place close to the starter , it feels the starter and sends this info to the computer . I did what he said , my starting turned over so much better . Before I would say 2 or 3 cycles then the engin would start , on the other side I wills say almost instant . I'm not a mechanic but he was right on my Murk 5.7 in my 2005 28 footer
One thing to add - the Mercruiser 5.7 (and probably the other displacements) uses a roller cam rather than a your standard flat lifter setup you find in the on-road engines. This works well for extended idling, which these motors do. Solid motors for sure.
I love mercruiser inboard , had an 84 5.7 with an m.r. outdrive. I flushed the engine after every use , kept oil changed and changed outdrive oil yearly too
Great video with lots of useful information. However I would have to disagree with your statement about "repaired" block crack not lasting more than a season. I've personally patched a couple with permatex the right stuff and they are still going strong. Totally acceptable quick fix imo. It's not a structural crack and the cooling system is not under any substantial pressure. Replacing the block for a hairline crack on the cooling system side is silly. That being said, it should definitely be disclosed if the boats being sold.
My 4.3 sucked for about a year of inconsistent use. Got my Mariah SX18 for 4k that wasn’t used too much, but it was never looked after super well. Used to leave my stranded all the time, dump oil, or just shut off cause the damn wire clips kept getting brittle and cracking. Now it runs perfectly and it’s not left me stranded in a while, although it doesn’t enjoy going from Florida to the mountains in North Carolina
I had a VolvoPenta 5.7 - similar setup - and I am so glad to not have to deal with an I/O (sterndrive) engine any longer. Being a brackish/saltwater boater and living in an area that freezes my I/O always made me very nervous.
The worst part about the SX era volvo drives is the hydraulic system. The way they designed it, if you have to replace one hydraulic line, you have to replace the whole system! And they sell the whole system as a package cuz they KNOW what they did to you. Dissimilar metals corrode permanently in place. Even if you can unthread the fittings, the threads come out with it. Suuux! The worst is the pass-thru hydraulic manifold part. It's $400 by itself!
I had a 165 hp, 6 cylinder that I changed out the block. That boat and engine ran from 1988 through 2009. At that point the engine was tired and the hull was tired so I scrapped it. I would drain the block including the intake and exhaust. Drain and replace the grease in the lower unit and add stabilizer to the fuel. Never had any issues when starting in the spring.
Having not one idea about boats a thought occurred to me. Why not use a heat exchanger to cool the engine? Use regular antifreeze then use the raw water to cool the coolant? I know weight and cost are a problem but I don't see a valad reason not to do it.
That is common and considered a premium option. Referee to as closed cooling as opposed to raw water as he described. Also works better on EFI engines as it keeps them water temp more consistent
The quick connect fittings between the block drains, and the hoses that go to the grey bottle, are famous for plugging with sand/rust, just pulling the one blue plug won't keep it from freezing and cracking
Mercury usually specified forged components in their rotating assemblies, so engines with freeze damage like the one you pulled still have usable, USA-forged steel cranks, rods and pistons inside them. I'm not aware of any aftermarket companies who are forging new crankshafts in the US, so if you're building a small block/big block Chevy, a neglected, low-hour boat engine is a cheap source for high-quality parts. I'll take a forged GM crankshaft from the 90s over a new Chinese one any day.
in addition to the differences between the gm truck motor and Mercruiser marine motor you already mentioned, the connecting rod bearings and the main bearings are also different
Thanks Rich love the channel. I live in an are where its below 10 degrees for several months in the winter the last boat I owned was a maxim 20sl with the 6 cylinder merc and I just ran coolant through the motor every year when I put it up and it stayed outside for six years never had an issue. I pulled the plugs the first year then a guy at the boat shop suggested just running coolant through it so I did and it worked never cracked anything. The problem i had was with water pumps idk why but 4 water pumps in 6 years.
You got it right, neglect is the issue. I have a question for you what if a guy had a perfectly good 350 mag and wanted to put in a truck would the cam work in a vehicle?
I have installed many l31 marine engines in trucks. I was getting really good deals on brand new l31 vortec engines. I prefer the l31 marine manifold and I have installed many of them in 96-2000 trucks and SUVs.
I to will never own one of these boats, but the information and knowledge of this guy is AWSOME, and I thank you. I saw a 1969 Dodge Charger being built up a while ago, you car guys might have saw it on the show circuit or mags, it had a mercury motor in it, kinda looked like a cross between a flathead and hemi, the guy told me Mercury wants to get in the automotive end of motors, IDK. Anyways, thanks for the lesson.
Funny how everything mechanical revolves around proper maintenance. Besides fluids, brakes, filters and tires I’ve only spent about $1,500 USD on my 21 year old PSD and my buddies don’t do anything except drive their vehicles and they spend thousands on diffs, trannys, turbos, engines, etc. This gentleman and his builder just did a great video reviewing synthetic oil and the vital importance of proper warm ups of the engine and proper maintenance. Love this channel since he’s a straight shooter.
Heat exchanger. I run two of these in Alaskan saltwater. I never let raw salt water into my engine, run a oil cooler, coolant heat exchanger, and wet exhaust. Never drain anything for winter, I just pour about 3 gallons of RV Antifreeze into my raw water scuppers and it’s ready to go.
I always pulled my thermostat out hooked my bunny ears up and dump raw antifreeze in the bunny until antifreeze comes rolling out and by using 💯 per cent antifreeze if you do miss some water the pure antifreeze fixes that .
hi guys, new to the boating world here. I take pride in learning how to do my own work but a little behind in the learning process. I bought a boat from an old engineer in Detroit, Michigan who said the merc had a cracked head but that it was properly repaired (sleeved) when he bought it. I have only owned it a couple weeks now. I am starting out with purchasing all safety equipment before I go out and bought the shop manual for mercruiser. It is an 1986 tiara 5.7L. I would love any input you guys could pass along. I maintain all my own vehicles but it has been a long time since I worked with non fuel injected motors. I was in the Navy when distributor caps were still being used. I found a few spots that were soft on the top deck so I am going to get my first experience doing some fiberglass work. I have thought about using coosa board to replace soft spots which to my understanding is balsa. Loved the video by the way. I think you converting to diesel would be an excellent video.
What engine should we review next?
6.7 cummins, id be interested in learning more about that engine
The lotus designed , mercury marine built LT5 from the C4 ZR-1!
Anything Ford Ecoboosted...😮
13B
2uzfe out of the toyotas
Back before we had kids and I could afford to put gas in a boat I pulled the perfectly fine 350 small block and put a 383 stoker kit in.
My wife was not pleased, I was very pleased with the end result.
I used to go skiing in a 18ft with destroked 400 383. was lots of fun and bloody scary coming off @50knts.
Will never own one of these, this will never affect me, yet here I am.
You say this and yet your looking to buy a boat.
I’m here with you lol
Bask in the glory 😅 and grimace in the agony 😢. Either way we enjoy 😊.
Same
The best way to have a boat, is to have a buddy with a boat....i know better than to own the boat...but ill probably end up with one 😂
HUGE NOTE TO ADD. The starter, alternator, carb overflows were different than a truck or cars. They are supposed to be marine grade so there’s no open spark risk. The carb needs to have the jhook on the overflow in the event your floats stick open. Insurance used to cancel claims due to inspection’s showing non marine parts were used
Well, when someone puts a truck/car engine into thier boat, the generally always use the accessories from the boat engine, so no need to panic 😬
I dont mean to be rude, but if you're stupid enough to put a non marine part on a boat, you deserve what happens.
Ngl, they actually recommend using marine plywood over treated osb in a lot of scenarios.
As these engines get older internal scale will form that often plugs up the block drains and manifold drains. Use a small screw driver to poke into the opened petcocks to ensure all the water comes out. On the later models with connected hoses to a single drain remove the quick connect hose connection on each side of the block and insert a small screw driver to move the scale and allow the water to fully drain. I learned this the hard way and was told how by seasoned marina mechanic what I needed to do in the future.
This! I bought my boat with a bad engine and found this exact situation when I pulled it apart.
What about using green coolant for storage? It has rust blocker? That's what friends do with race cars.
@@workingcountry1776 You can't. Boat engines are open loop.
@@alexandermckay8594you can remove hoses an add coolant to them and it will either flush out water by replacing it or dilute the water enough to not freeze.
@@workingcountry1776 run muffs from a Rubbermaid container full of the coolant. Put another Rubbermaid under the prop and run the engine until the water turns the color of the coolant. There are videos on TH-cam here but I've never done it yet.
I work on alot of these and 100% agree with you the biggest issue they have is poor winterization and maintenance
Brings a smile to my face to see some marine content on the channel! Mercuiser didn't continue on with the LS line of engines but volvo penta did. Took a long time but all modern gasoline I/O's are running catalysts as well now. Albeit they are falling by the wayside of the simplicity, servicability and reliability of modern outboard engines .
Im sure youve got a good marine contact near by you but if you ever have any questions dont hesitate to reach out - northern ontario based marine tech of 14 years 👍
What is the current 6.2L merc cruiser based on?
Yep, had a Volvo Penta in my Bayliner. Long gone now.
I had an old wakasha/ford 302 in a boat. I put a thermostat in it. Got a little better efficiency, but more importantly I got hot water to put in the wetsuit before jumping into the 5 degree Celsius lake.
Seriously?
@ you bet!
That was awesome! Im a retired disabled MERCRUISER mechanic, you brought me back to the shop!
You covered basically everything!
The one thing I'd brought up is the "CORROSION SPAYS?" And fuel stabilers, thank you for the journey back to the best years of my life. Nice shop! I'd bet alot of dreams came threw there. Keep up the keeping up!!
Another common issue with these engines is the oil pan will rust away and pour oil out, requiring an engine out job in most cases!
Awesome video!
Usually, it's the oil pressure sensor that will rust away, allowing all the oil to leave the engine. I seen some really bad oil pans on these mercs, but never rusted thru. If the engine were that bad, it wouldn't be in running condition anyway. A starter will rust solid, long before an oil pan will. 😂 plus, the 4.3 oil pans are cast alum, instead of tin. And have plastic timing covers that are embossed with: replace if removed.
I was a boat mechanic for 8 years and worked on every brand. I did lots of those JB weld block repairs and never saw one come back leaking.
30 plus years ago i did enjoy being on my friends boat powered by the GM 4 cyl Iron duke. It could pull 2 skiers and would run all day on 20 gals of fuel and was quiet
Had that little engine in a boat back then and it was great. Especially on fuel consumption.
My current boat has a $75 junkyard 4.3 from a blazer. I put it in 4 years ago and it's been phenomenal 😂
Did you switch oil pans? I'm doing the same things now.
@brandonlarry1645 nope I left the Blazer oil pan on it. I did switch dipsticks, so you need to fill your engine up with the correct amount of oil, then calibrate the boat dipstick to read correctly with the new pan.
Ho or reg 4.3?
@@tonydiesel3444 I'm not sure
For that price, you can do no wrong. Any win, even for a day, is worth it.
Been on the same 350 Merc for 30 years... Thousands of hours, all original right down to the plugs and wires for over 25 years. The only problem we ever had was the raw water pump and finally a hairline crack in one of the cylinder heads. Just goes to show if you take care of it it'll take care of you.
Is your boat a fresh water or salt water application?
@windward2818 Both. Port is brackish, about 5 miles inland, occasional trips upriver, but most weekends are spent in the salt. Don't ask me why or how it's been so tough, but never would I trade for another boat or motor.
The Bravo III, on the other hand... Number 3 was rebuilt, the lower unit was replaced the following season, and this will be the third season on number 4. If they don't pit themselves to death, they just self-destruct.
@@dozerfarms My boat is 24 years old and like yours I'm still on the original engine, original starter, carb, alternator, everything. Thousands of hours and she still runs strong! I replace the water pump every other year, and all the fluids get changed yearly. 100% salt water use and the boat gets winterized every year by me. Sounds like you know how to take care of a boat and its engine. These are great motors. She'll still hit 50 mph on plane...
@jamess3532 Haha yessir! I do everything myself that doesn't require a special tool to do. Last weekend was waxing and waterproofing the canvas, the week before was the bottompaint, anodes, and outdrive oil, all I have left is to throw the rest of my stuff on board, hook up my instruments, and drop her in. Here's to a great 2024 season! 🍻
@@dozerfarms I'm prepping mine for the season too. It will be a few weeks before she gets in the water though since I decided to replace the flooring in the cockpit. She was getting a little soft around the engine shroud. Just my opinion here, but learning how to maintain your own boat is paramount to getting the most out of it. I think a lot of folks purchase boats without learning what it takes to properly maintain them. If you do everything yourself you know it was done right. Happy boating.
I worked on these for over 10 years and was certified on Mercury outboards and Mercrusiers . Went to merc school in Dallas. In school we were told the only internal parts that were changed from the GM engine was the camshaft that made its power mainly in low to midrange around 4200 rpm’s. And installed Stainless steel valves.
You did an excellent explanation of the mechanical differences between automotive and marine engines. But you forgot an crucial difference, the electrical system. The electrical systems for marine application, not only the engine, is different than automotive. The engine bay of a car is very well ventilated, you can see the ground when you open the hood. For a boat, when you open the engine bay of an inboard like yours, you see a solid sealed (hopefully) hull. There is nowhere for the gas fumes to go. This is the main reason for activating the venting fans before starting your engine.
The electrical system of a marine engine is specially designed to avoid the electrical arcs of the various form of switches to be in direct contact with the surrounding air. Even the wires are different, each braid is individually tinned to prevent corrosion. Never use a car alternator, marine grade alternator will have double insulation to prevent shock and sparks.
Rich, be careful with the LS swap, use marine grade electrical system.
That definitely gives me a higher appreciation of what Mercruiser has done with these engines. It is great to see how you speak directly to us backyard mechanics.
He mentioned draining the blocks for the winter layup. Don't forget to run pink biodegradable Antifreeze through the engine via the raw water pickup. Either do it while the engine is hot or remove the thermostat and run. Run until you get solid pink coming out the exhaust. You will not crack a block that way. 4.3s love to crack behind the exhaust manifold.
I was using the cheap pink stuff from Walmart then I realized you need the more expensive stuff rated for engines. The cheap stuff is alcohol based and not good. The expensive stuff has propylene glycol.
@@joesilverbliss1721 You want to keep using the cheap stuff and drain it out after you run 5 gallons through the engine. The procedure is simple: Use a 5 gallon bucket with a spigot on the bottom that you can connect a short garden hose to and run it to your muffs. Run the engine until the thermostat is open using water and then switch to the coolant and run it until your 5 gallon bucket is empty. I collect most of it and store it back in the jugs for the following year. Pull your blue drain plugs and your done. Do not use radiator coolant rated for automobiles. Lots of youtube videos showing various methods....
We mainly use the pink for the water systems in the cabin. It's much cheaper to just drain out the water from the engine. Draining all the water from the water system is much more difficult.
@@thediplomasta5891 As long as you can guarantee that there is absolutely no water left in your engine cooling system than you can get away with not running the antifreeze through it. Peace of mind and extra assurance is why the majority of us flush with RV antifreeze. Especially for those of us who live in extremely cold places where temps will stay below zero for a week straight, or longer. That way there if any residual water is trapped it's at least displaced with the antifreeze and won't crack your engine block. Like I said, I collect it all in a bin placed under the stern drive and put it back in the jugs for the following year. It hardly costs anything doing it this way and it's a lot cheaper than having to replace an engine block! I know some people use JB weld to fix cracks but that's not a real fix.
I used to build the 3.0L I4 mercruiser engines for sprint cars, good engines.
Ive had mine for 14 years in my bayliner never had a issue great engine
Recommend me a head gasket pls
4 bolt main GM blocks have not been used in the production marine world since the early 80s. Brass freeze (core) plugs and different camshaft are main differences between automotive & marine blocks sourced from GM.
I look forward to your LS swap series. Keep up the good work.
right on scott
I believe the late model 350 magnums were all 4 bolt mains.
My 2011 350 mag mpi is a 2 bolt
My 2000 Mercruiser 7.4L is a four bolt main.
thank you!!!
Nice! Good to hear positive comments towards mercury engineers, as my GF was Mercury's original chief engineer.
My family has a '92 Mercruiser 4.3l. When winterizing, we drain everything then add a little plumbers antifreeze to the exhaust manifolds. We found the drain on the exhaust manifolds isn't truly at the low spot and ended up with a little water pooled at the back. We got lucky and were able to get the manifold repaired but now we always add a little antifreeze just to be safe.
I work on boats on the coast I/O boats have fallen out of style to much headache. Outboards are taking over for the smaller sized boats. They were designed to be on a boat right from the start. They hold up well and in my opinion much easier and enjoyable to work on.
And so much cheaper to own!! Compared to diesel boats, the annual running costs of OBs are so much cheaper even if they use twice the amount of fuel!
That’s funny the cost to have it serviced and replace it is 10 times the cost of a small block Chevy@@mz22wa
Inboards take up too much room on smaller boats.
Agreed. And the new 4 stroke OB’s are so quiet now. You can barely hear them idle except for bubbles from the exhaust. I have ‘06 Merc 150 EFI 2 stroke that’s fuel/oil injected and it’s loud. Sounds cool when you run it in the driveway with water muffs on it though.
My Volvo Penta 305 required very little maintenance for 15 years (oil and filter changes and draining the block every winter) until sand blocked one of the drains and cracked the block. Still ran great but a bit of a leak problem. I bought a 380 hp 350 for $3500 and swapped computers for the fuel injection. Runs great, a 380 hp outboard would probably run 30k! I'm glad I got a inboard. I'm sure your "small" boat is much bigger than my boat LoL I wouldn't take mine on the ocean.
I have a truck engine in my boat. It's a 1995 Bayliner. I pulled the original 4.3 engine because it was not winterized and then compared both engines while putting on all new gaskets on the truck engine. They were identical except for the camshaft which I did not check and did not know that there may be a difference in camshafts at the time.
Did you change the oil pans or did you keep the truck oil pan on it? I'm doing the same thing now
@@brandonlarry1645 My 4.3 from my boat was 1995, and the replacement engine came from a 2002 S10 truck. I kept the truck oil pan because the pickup tubes were different, so the oil pan from 1995 did not work on the 2002. I had to modify the oil dipstick a bit for it to work, considering that the dipstick had to be from the same oil pan. I had to use the water pump from 1995 because of the v belt pulleys. The pump did fit, but the timing cover did not work for that water pump. I had to modify one of the bolts (make a flat head) so that the pump would fit. What year is your boat/engine?
I took out my cracked 5.7 and completely built a 383 stroker along with Corsa 4” side exhaust. What a monster!!!
FREAKIN BEAUTIFUL !
I used Devcon epoxy on an exterior head crack in 2005. I’m still using it today around 1000 hours later. It’s sure worth a try. 1990 4.3👍🏻.
One of the few perks of living in S.Florida: NO FREEZE worries. 👌😁
That's what Texan's said... And then I got a cheap boat
Thank you so much for pointing out the difference between marine and automotive cams. You have no idea how many calls i get during lake season down here in Nevada when people hydo lock their brand-new motor first go out. Also down here we usually just get a big bucket and fill it with coolant drop the outdrive in and run it for a few minutes. Never had a problem, our 21-foot sleekcraft has had the same motor since 1996 and it still runs, we don't know how its honestly insane. Its a Merc alpha 260hp 350 sbc thing is a champ.
Look out for sand/silt build up in your engine block. This affects the cooling, but it also can trap water that won’t drain when you open the plugs to winterize (ask me how I know). Pull the drain plugs completely and use a piece of stiff wire to clean out the drain passages as best you can. I then fill the block with rv anti freeze through the thermostat housing and let it run out the drain holes.
Back in the 90's I worked at a local marina. We did hundreds of winter/summerizations on boats and had large storage buildings for winter. I think I still have fiberglass shards in my forearms from reaching around the larger engines stuffed into the fiberglass boats. We (the young mechanics and helpers) always preferred to work on the Mercruiser stuff, and specifically the Cobalts. They were simply a better built and better engineered pleasure boat than any of the others at the time. Bayliner and Maxim were always the worst. We called them the "Kraco" of the boating world.
Maxims, an engineering disaster from 12v power distribution to engine space ventilation.
My 1994 Cobalt 220 with the 5.7L still running strong. Everything original minus plugs. Great boats, excellent quality even by todays standards.
Ive had boats all my life !! That was a great presentation, i will forward this to my neighbor who has bought an inboard/outboard 4 cylinder
Great video. Mine is a 1999 Crown Line 23 ft 5.7 carbed. Bravo 3 (I think, 2 props) out drive, Fast boat and I have it professionally serviced twice a year, fall and spring. I think I am doing it right as I have no time to work on my boat myself but love it. Not a lot of hours but 100% good and reliable. Always kept inside and a great boat for lake Pend Oreille, 1600 ft deep!!!
Great video! I am currently rebuilding a boat with a 250 inline Mercruiser. You hit on some good points bro!
Excellent engine
I do everything you mentioned in the video, in addition I warm up the engines using the muffs until the thermostat opens then switch over from the hose to a bucket of anti freeze. Once the antifreeze comes out the exhaust I then fog the engine until it stalls out. Once it stall out I open the drains in the manifolds and the block.
So far so good.
I really enjoyed this video! I used to have a 1995 23' Maxim Bowrider with a mercury 7.4L MPI (454). It was a lot of fun, but also a lot of work.
Compression testing is a must, checking all spark plugs, coils, distributor, spark plug wires, all other wires also, definitely check the oil
Good vid, Matt. When I worked at a marina, the running joke was the difference in most parts was a coat of "phantom black" (Mercury's black paint name) and the quadrupling of list price, although that isn't _really_ true.......
As a 10 year mercruiser tech and a long time follower of your channel i thought for sure I’d see this video and see something you may not have, but your good! That being said if you need a random part we’ve got a hoard of mercruiser parts at our Maryland shop! Awesome video
I think he had the cylinder head info backwards between the two engines. I would definitely use the 305 heads on the carb’d 350 engine. A 305 head usually has a much smaller combustion chamber and would raise the comp. ratio a great deal. I would transfer all the top end from the FI engine and stick on the carb’d 350 block. Run premium gas and hit the lake. 0:03
305 heads on a vortec 350 will make it a dog.
@@DdabsolveRich’s isn’t a vortec
@@Ddabsolve if you go back and look, his 350 carb’d engine is an ‘87 model. 305 Vortec heads would not make that engine a dog, plus he could use all the stock EFI from the original boat engine. 305 Vortec heads do not flow as well as the 350 Vortecs but they flow fairly decent, and prolly better than the ones that are on the carb’d 350.
The Vortec 350 head outflow Vortec 305 heads.
The Vortec 350 is already over 9:1 compression with the 64cc heads.
Best advice i ever got from an experienced gentleman was, if it floats flies or fornicates, rent don't buy!
I don't think I have ever seen a more informative video. Kudos.
He has some good heads for that OBS chevy off that vortec marine engine! ANOTHER VIDEO IDEA!!!
WOW, thank you sir. Exceptional content here. Honestly, anyone who isn't able or doesn't watch this video before buying a used boat with a Mercruiser is missing out. OMG, I can tell you've saved me thousands of dollars with a 15 minute investment. I cannot thank you enough. Subscribed. Liked.
Intake manifold gaskets are another one. If converting a truck engine to a marine application you have to swap the intake gaskets as well.
LS intakes are dry
Having built a truck engine for a boat that cracked. I noted the intake gaskets were different and a side by side comparison showed the head gaskets had way smaller passages for coolant flow on the boat motor. I would guess due to them running colder in a boat.
@@V8Power5300 only within the last few years have LS based Mercruisers really become a thing. The vast majority are still SBCs.
@@05milmachine90 I forgot about the head gaskets as well
Go and have a look at B is for Build. He swapped from twin v8 Cummins to twin high performance LS motors. It's like a slow motion train wreck. The original engines weren't Cummins best effort, but he killed one by not checking the oil, which it was burning fast.
Why that hack didn’t just put in a pair of Cummins 6BTs or QSB 5.9/6.7s is beyond me. He doesn’t even get his hands dirty
@@mz22wa The original engines were 14 liter 419hp Cummins VT903Ms. He could have got another for around $10k. There are QSB6.7s that would beat the 903 power for a time. The 'government' rating on the 6.7s will go to 550hp. But continuous rating is 305hp. CAT C12 ACERT 12l diesels will run about 700hp for $40k. 500hp Yanmar diesels are about $25k each. Yanmar 6LT640 640hp marine diesels are $35k and would probably have worked too.
I think B (Chris?) has said he doesn't have much experience with diesels but lots with LS.
I would have stuck with diesels too but the converrsion is more challenging & prob makes for better content.
To be honest, i would have sold the boat instead of dealing with the blown engine!
@@JayneCobbsBunk he doesn’t have experience with anything. Absolute hack job
Running in saltwater it is a glycol based coolant with heat exchanger. More complex with raw water pumps and heat exchangers but when maintained, more reliable to my mind.
I agree former USCG.
Excellent video. Just bought the same boat with that engine. So far so good but time will tell.
Great content- thanks for posting. I’ve spent hundreds of hours hanging upside down in I/O engine bays scraping arms and knuckles while winterizing. It was a nice change to switch to outboard power and be able to just stand beside the motor to work on it as well as having about 95% of the cooling water just self drain every time you turn the motor off.
While you are working on the engine swap carefully go over the outdrive, check the rubber driveshaft and shift cable bellows for aging, wear, cracking and leaks. Sinking a boat that way ain’t no fun at all..
First time viewer - excellent. Loved it. Great info.
The 8.1 was used in Marine app good engines
I've put several junkyard 4.3s in boats. Only difference I ever found d was the cams. Swapped the marine cams in and away they went. Lots of happy customers
@1:35 love the "ladder out" vibes
its a shame they dont have the fenders out as well
My buddy is a commercial crabber and he had a 5.7 mercrusier in one of his older boats. To insure he didnt crack the block/manifolds in the winter. When he winterized the boat, he would flush it with fresh water using the muffs and garden hose. Then right before he would fog the engine he would mix 2 jugs of straight antifreeze and water in a 5 gallon bucket. He would then stick a sump pump into the bucket to help pump the mix into his flush muffs. He would run the engine until he had his special mixture running out the exhaust. I guess it was easier doing it that way then trying to drain the water out the correct way.
Great Idea, today you would use RV antifreeze.
@@philipmackin1025 Why?
@@Watchyn_Yarwoodpink AF is less toxic
I knew a guy who used the pink RV antifreeze in his 350.
@@conrasm I would be concerned that this "pink" antifreeze is not formulated for automotive engines as is engine antifreeze, therefore I would not use it personally.
No matter what slight issues they may have. There is not an outboard motor that sounds as good going across the lake at 4 grand. This is my humble opinion. I have a 2016 383 stroker in my 23-foot offshore boat. I live in florida and don't have to worry much about winterizing the engine. I pull it out every couple years and let machine shop go through it. Love it. Sounds awesome.
"I'd never swap from Diesel to Gas." First thought - follows B is for Build 🤣
At least Chris' videos are a help in figuring out manifolds and such. I am actually happy to see the twin LS engines seem to handle his boat quite well. I will also be curious to see what you end up running for prop once you've got a lot more HP to work with, this should be a really fun boat.
First guy I thought of too when he said that 🤣
In stead of draining the engine we just had a big tub of antifreeze, ran the outboard in and pumped it in, did that for 5 winters never froze. No issues also stopped the rusting.
I'm a retired west coast fishing guide. Not many pros use ANY Mercury engines of any kind
Good breakdown regardless
Such an informative video. Considering Rich is relatively new to marine, the content is still incredibly well researched. I can’t wait for B-Is for Bodge’s LSX powered boat to spectacularly blow up
Rich you talk about the blocks freezing and describe the drain ports. Although the drain ports work their is actually a much easier way to keep them from freezing. Simply you get a pair of muffs on the lower and pump non toxic antifreeze in then fire the motor up and run it for about 5-10 minutes. According to Merc this will fill the entire raw water side of the cooling system with antifreeze and your good. And as long as u use non tox u don’t have to drain the antifreeze out in the spring.
The secret is to live in a part of the world that doesn't stay frozen for 9 months out of the year. If it never freezes you dont have to winterize! Only fun about the cold is snowmobiling and that gets old quick.
Tell the Texan's that, because I got a nice cheap boat. It only takes once
@@DEBOSSGARAGE I am a Texan. You realize I was just kidding and ragging on Y'all Canadians? Every few years we have a freeze and have to actually winterize our boats. The ones that sit outside anyway. It never, ever, gets cold enough to worry about something in a garage.
Firs statement probably the most honest words ever spoken! The owners are the problem. Ive had them unplug hour meters and swear they had not used it since i fixed it. He didnt know i put an hour meter in the engin compartment. Others didnt realise i can hooj up a laptop and see every single second of how you ran your engine! Yup, 2 hours with 6psi oil pressure and 4 at 200f, that pretty much voids your warranty.
My hands down favorite Mercruiser engines are the 165 both the inline six and the four banger. Both very economic and incredibly reliable. My 1976 Merc 165 L6 runs at a religious 143 degrees and only burns about 5-6 gph at 3200 rpm and 26-27 mph. That's its sweet spot and cruising speed. I'm slowly restoring an 18' 1976 Apollo tri hull. With a 15"x17 pitch prop, just me and a full tank of fuel on perfect water she does 41 mph at 4500 rpm WOT. For such a heavy boat it has a pretty good hole shot and is a fantastic boat for tubing.
Many times late in the year I've put eather a space heater or a halogen work lite in the engine bay to keep it warm enough over a unusually cold night. Worth it to get another couple warm boat days inn.
just watched your stuff grea tinfo i just got my 35o back from machine shop after two years and forgot where the knock sensor were its a 2001 350 mpi was hoping to spy on your motors but did not see them great job
I have a 2005 5.0L. Make sure you changes the plugs regularly. When i bought the boat the plugs had never been changed. They were rusted in place and disintegrated. I had to pull the heads to fix that problem. Major pain. All good now. Boat runs great.
Mine has had low compression in the rear stbd cylinder since I bought it.. wasn't aware of it until 2 years in when a mechanic found the problem
Had a military sub engineer today working in a motor shop . He told me to take my knock sensor and put it on the other side of the motor . In its current place close to the starter , it feels the starter and sends this info to the computer . I did what he said , my starting turned over so much better . Before I would say 2 or 3 cycles then the engin would start , on the other side I wills say almost instant . I'm not a mechanic but he was right on my Murk 5.7 in my 2005 28 footer
One thing to add - the Mercruiser 5.7 (and probably the other displacements) uses a roller cam rather than a your standard flat lifter setup you find in the on-road engines. This works well for extended idling, which these motors do. Solid motors for sure.
I love mercruiser inboard , had an 84 5.7 with an m.r. outdrive. I flushed the engine after every use , kept oil changed and changed outdrive oil yearly too
Great video. Glad to see I’m not the only one that forgets to put the ladder up. LOL
The Merc Quad Cams would sure make good discussion. For me maybe in a few decades when the price gets right. 1650 hp ain't bad.
Great video with lots of useful information. However I would have to disagree with your statement about "repaired" block crack not lasting more than a season. I've personally patched a couple with permatex the right stuff and they are still going strong. Totally acceptable quick fix imo. It's not a structural crack and the cooling system is not under any substantial pressure. Replacing the block for a hairline crack on the cooling system side is silly. That being said, it should definitely be disclosed if the boats being sold.
And actually yeah J-B weld might only last a season because it doesn't flex or grab like permatex the right stuff
Mercrusers were manufacturing in stillwater Oklahoma good jobs back then
My 4.3 sucked for about a year of inconsistent use. Got my Mariah SX18 for 4k that wasn’t used too much, but it was never looked after super well. Used to leave my stranded all the time, dump oil, or just shut off cause the damn wire clips kept getting brittle and cracking. Now it runs perfectly and it’s not left me stranded in a while, although it doesn’t enjoy going from Florida to the mountains in North Carolina
I had a VolvoPenta 5.7 - similar setup - and I am so glad to not have to deal with an I/O (sterndrive) engine any longer. Being a brackish/saltwater boater and living in an area that freezes my I/O always made me very nervous.
The worst part about the SX era volvo drives is the hydraulic system. The way they designed it, if you have to replace one hydraulic line, you have to replace the whole system! And they sell the whole system as a package cuz they KNOW what they did to you. Dissimilar metals corrode permanently in place. Even if you can unthread the fittings, the threads come out with it.
Suuux! The worst is the pass-thru hydraulic manifold part. It's $400 by itself!
I had a 165 hp, 6 cylinder that I changed out the block. That boat and engine ran from 1988 through 2009. At that point the engine was tired and the hull was tired so I scrapped it. I would drain the block including the intake and exhaust. Drain and replace the grease in the lower unit and add stabilizer to the fuel. Never had any issues when starting in the spring.
Thanks for showing where the tag is.
Having not one idea about boats a thought occurred to me. Why not use a heat exchanger to cool the engine? Use regular antifreeze then use the raw water to cool the coolant? I know weight and cost are a problem but I don't see a valad reason not to do it.
That is common and considered a premium option. Referee to as closed cooling as opposed to raw water as he described. Also works better on EFI engines as it keeps them water temp more consistent
That's what we are doing with the LS swap. Already have the heat exchanger
The quick connect fittings between the block drains, and the hoses that go to the grey bottle, are famous for plugging with sand/rust, just pulling the one blue plug won't keep it from freezing and cracking
He's my pet now
Mercury usually specified forged components in their rotating assemblies, so engines with freeze damage like the one you pulled still have usable, USA-forged steel cranks, rods and pistons inside them. I'm not aware of any aftermarket companies who are forging new crankshafts in the US, so if you're building a small block/big block Chevy, a neglected, low-hour boat engine is a cheap source for high-quality parts. I'll take a forged GM crankshaft from the 90s over a new Chinese one any day.
in addition to the differences between the gm truck motor and Mercruiser marine motor you already mentioned, the connecting rod bearings and the main bearings are also different
what about running lpg on said boat?
loved the video my cousin had a 3.0 4 i called it the super duke damn reliable pushrod engines
Thanks Rich love the channel. I live in an are where its below 10 degrees for several months in the winter the last boat I owned was a maxim 20sl with the 6 cylinder merc and I just ran coolant through the motor every year when I put it up and it stayed outside for six years never had an issue. I pulled the plugs the first year then a guy at the boat shop suggested just running coolant through it so I did and it worked never cracked anything. The problem i had was with water pumps idk why but 4 water pumps in 6 years.
Excited to see your ls boat project
You got it right, neglect is the issue. I have a question for you what if a guy had a perfectly good 350 mag and wanted to put in a truck would the cam work in a vehicle?
I have installed many l31 marine engines in trucks. I was getting really good deals on brand new l31 vortec engines. I prefer the l31 marine manifold and I have installed many of them in 96-2000 trucks and SUVs.
I to will never own one of these boats, but the information and knowledge of this guy is AWSOME, and I thank you. I saw a 1969 Dodge Charger being built up a while ago, you car guys might have saw it on the show circuit or mags, it had a mercury motor in it, kinda looked like a cross between a flathead and hemi, the guy told me Mercury wants to get in the automotive end of motors, IDK. Anyways, thanks for the lesson.
Mercruiser was making their own blocks when got to tour the Oklahoma factory in highschool. Sadly they left the state not long after.
What's wrong with winterizing by running your engine with the outdrive in a barrel of 50% antifreeze? You won't worry about drain plugs.
Very informative as always, thanks Rich.
Had on in a Crist-Craft with a merc-cruiser (5.7) for over 10 years and never had a single problem with it at the Lake of the Ozarks.
Funny how everything mechanical revolves around proper maintenance. Besides fluids, brakes, filters and tires I’ve only spent about $1,500 USD on my 21 year old PSD and my buddies don’t do anything except drive their vehicles and they spend thousands on diffs, trannys, turbos, engines, etc. This gentleman and his builder just did a great video reviewing synthetic oil and the vital importance of proper warm ups of the engine and proper maintenance. Love this channel since he’s a straight shooter.
Heat exchanger. I run two of these in Alaskan saltwater. I never let raw salt water into my engine, run a oil cooler, coolant heat exchanger, and wet exhaust. Never drain anything for winter, I just pour about 3 gallons of RV Antifreeze into my raw water scuppers and it’s ready to go.
I always pulled my thermostat out hooked my bunny ears up and dump raw antifreeze in the bunny until antifreeze comes rolling out and by using 💯 per cent antifreeze if you do miss some water the pure antifreeze fixes that .
I have a couple 5.7's in my 30' Sea Ray Sundancer, never gave me any issues..but it takes some maintenance.
scored a marine 305 and it is throaty on the road, found it new in the box which was beat from setting around and the price was awesome fo rit
Some marina engines use a heat exchangers which means there is antifreeze in the cooling system
hi guys, new to the boating world here. I take pride in learning how to do my own work but a little behind in the learning process. I bought a boat from an old engineer in Detroit, Michigan who said the merc had a cracked head but that it was properly repaired (sleeved) when he bought it. I have only owned it a couple weeks now. I am starting out with purchasing all safety equipment before I go out and bought the shop manual for mercruiser. It is an 1986 tiara 5.7L. I would love any input you guys could pass along. I maintain all my own vehicles but it has been a long time since I worked with non fuel injected motors. I was in the Navy when distributor caps were still being used. I found a few spots that were soft on the top deck so I am going to get my first experience doing some fiberglass work. I have thought about using coosa board to replace soft spots which to my understanding is balsa. Loved the video by the way. I think you converting to diesel would be an excellent video.
How do you distinguish a two bolt from a four bolt engine?
I'm curious about the 6.2 mercuisers. They look like a typical small block chevy but in an odd displacement