I’m getting an 18hp 1960 Johnson 2 Stroke that we found in the back of my grandfathers shed. He upgraded to a 25 horse in the 70s and it hasn’t run since. Now that I’ve conquered my Mercury 250 EFI (knock on wood) I need a new challenge! Going to find a little panga or Jon boat to put it on for the bay when it’s too windy for offshore.
About a month ago had a mobile mechanic do compression test on a motor I just bought and it showed that it was low on all cylinders. I took it to a Evinrude shop and they tested it and they were all perfect. $250 down the drain for a bad test.
Quick tip, if the compression test is low, spray a good amount of oil in the combustion chamber then re test, if the compression is now high it means the ring are damaged if it's still low it means your valves are bunt out. Thought you would have known this trick.
@@anndivine9989 leakdown test supplies continuous air that can be heard or felt leaking from exhaust, intake, crankcase. He even says it in the video. Love that your informative, Google it.
I had a 225 yamaha 2 stroke blow up when I was trying it out to buy. It ran perfect for a couple of miles and I figured it was good. I turned around and headed back in nailed it to get on plane and kapow... I did not buy it...lol and ring free stopped my 150 4 stroke from using oil badly, I could not believe it...thanks for your videos
Love the videos, wish they were out years ago. Got an old 40 hp merc collecting dust, rust and sun now because resources weren’t available then and local tech’s didn’t want to help because it’s a merc.
Here is my boat story, we were in our 42 invincible with quad 350s last year 30 miles offshore, one engine went out because it overheated, then we started to head back then another engine went out because of something in the bottom end, we started to get sketched out.. we were about 5 miles offshore and all the electronics shut off and it caused both the other engines to stop. Not a fun experience
I melted a 2.4 liter 200 merc when I was in high school. It overheated so bad that the pistons were stuck to the chrome bore. I also blew up an old v4 110 evinrude, the vro pump failed and it blew a window in the block.
I blew up a 2004 Evinrude 250 FICHT one time. My buddy called me to say the bite was on. I was low on gas had it full throttle and PUFF cylinder number 3. Blew a hole in the top of the piston. I always had an issue with that motor.
I would do a leak down test for a best results. but for a quick test to get a ball park area of problem your making short work of it with that test. I like your channel buddy! I've got educated with a Opti Max 225 in the past few months. your channel helped.
Hi Aaron, I always feel smart after watching your videos, even when I'm not fully understanding it all! ☺ But I am learning, and learning a lot!.... Thank you for all the work and effort you put in to your educational videos...
MAKE SURE YOU HAVE FULL THROTTLE AND FULL CHOKE ON!!!! I have personally seen 30% psi difference with these two conditions the other way (low throttle, choke off). This is especially true on older outboards I work on (60's and 70's).
I had a 2000 Yammy OX66 250 with 600hrs blow on me due to lack of fuel. Lost cylinders 2 and 4. Trade it for a used 2004 Yammy 300HPDI. Which also blew cylinders 2 and 4 due to a clog in the HP fuel pump basket filter. The HPDI, I resleeved / re built the cylinders and replaced the HP fuel pump. Now it's running fine. 👍🤞
Great Video's Bloke . Just been through the cracked block scenario on a 115 susuki. Takes the wind right out of your sails . But a new Honda and Minn Kota take away alot of the sting though it hurts the wallet.
I have never seen a outboard blow up in front of me always just the aftermath. Rods thru cases, wiring harnesses fused to the cases and heads. Motor got so hot I’m surprised it didn’t melt the cowling.
Had my 200 Ocean Pro eat a ring and spit it out at 810 hrs. Took out a piston and a head. Was told it was a carbon buildup. Had the power head rebuilt, running great now lots of power and it’s a thirsty 2 stroke.
Lol test drive, ignition coil shorted out and caught the wire harness on fire! Engine started over heating and then I saw the smoke :( had to let the smoke slow down, (in case of a fuel leak) to help smother itself out, then pulled the cowling and just patted the rest of the fire out with the rag lol that was an interesting ride first thing in the morning lol
I was 10 when my dad bumped me off at the river. I turned the key for the first trip after a long river and saw people waving their arms and screaming at me to turn around.. apparently the fuel hoses had dry rout and the engine caught fire very quickly. I was able to douse the engine using a 5 gallon bucket and Pauling water. The worst part really was paddling the boat up current to get back to the ramp. Lol
Exactly right. . That is why they are phasing two strokes out. . They last too long. . Everything is becoming disposable. . Years ago fridges lasted 30 years now you’re lucky to get 5 years out of a fridge.
The more parts that make up any machine means there are more parts that all have to be working together in sync. Every moving part has only so many moves in it before it fails. What that means is that there are many more parts working their way to eventual failure in a complicated machine like a 4-stroke.
I had a Merc 135 2-stroke outboard blow up real good. Crankshaft bearing failed. Much money was spent on a reconditioned crank, bearings, and the lower pistons and rings. 15 years later it is still running fine as it ever did. I can't sell it though, because as soon as people hear it had major work they don't want it. So I guess I am doomed to keep it until it dies. Could be a while though, I just did a cold compression test and I have between 102 and 109 psi in all cylinders, the two pistons that were replaced being the higher ones. Oh well it keeps me from dropping $50 grand on a new boat.
I did have a race kart engine and a Seadoo 787 blow on me while driving it. Detonation was the culprit on both. My ear suffered even with a helmet on in the kart. The head was curved up and the rod bent. That was when I was 12 yo. The 787 2 smoke ran on race gas. A friend who went to the race with me thought he was doing me a favor and put the wrong fuel in while I was in the head. Believe me, I came out the hole ahead of everyone and it ran so fast down the the front straight. I was going wow in my head and then boom just before the first turn buoy. LOL Towed in...oh well, lessons learned.
I have a 1975 70HP Johnson 4-Stroke I recently picked up and did a compression test. All three cylinders read 125-130. But is it normal for the tester gauge to go down or is that another issue with the motor? Thank you.
I have an early '90's 175HP mercury outboard on my 1993 23ft trophy Bayliner. Omw to Catalina island one of the ears on the prop broke off. It gave me alot of vibration and with less than 10miles to go, I decided to keep going at low RMP And low speed of (10MPH). I got to the island and putted around, fished for a few hours and decided to head back to San Pedro (25miles). After 15miles my engine completely shutoff . Got towed back to my slip and tried to start the motor and had no spark anywhere. Did a compression test and all read 65psi. Now I'm looking to repower my boat. 😫😫
Bought a 2001 merc 150 cxl 2 stoke 8 years ago. Compression test back then said 85psi on all 6 cylinders. We checked it with 2 testers and got the same results. Based on your info, i should have passed on the engine. 8 years later, it has the same numbers and same performance as it did when I bought it. Thoughts?
For an older 2-stroke like that, 85 is still a little low, normally that type you will see around 90-105PSI, but there are other factors to consider, like the starter and the battery and the power cables to the engine. As long as all the cylinders were 85, I wouldn't think to much into it either, 8 years of run time and who knows how many hours, engines obviously got no issues with it :) A lot of compression tests you want to make sure there isn't a difference between cylinders, they just give you an over all view of the mechanical health of the engine :)
@BornAgainBoating thanks for the reply. Unfortunately, i don't have an hour meter on this one and it has no computer to tell me. Merc doesn't provide numbers to look for except that they should be consistent. As long as it runs, we'll enjoy it. Plenty of power for my 20' Proline.
When doing a compression test on my 150HP 4 cylinder verado, do I need to take all the spark plugs out so I don’t risk the engine firing up when in key start the engine? Or can the other spark plugs stay in while you check the one cylinder? Thanks
Just had an incident with my Yamaha F150. I was on my way out on a trip and felt a loss of power so I went to neutral to check the engine and as soon as I came to a stop I saw smoke coming from my cowling. Turned the boat off just as the warning sensor came on. After pulling the cowling, I saw some oil pray on the engine was causing the smoke, so I got towed in. Once I got towed in I saw one bolt came loose from the manifold. Now I got a clanking noise coming from the engine after fixing the bolt issue and refilling my oil.
Ouch! Well, that's not good my friend, not sure what caused the lose bolt issue, but the spraying oil and creating smoke, that means the engine was hot enough to burn the oil to make it smoke when it hit the engine. Which most likely means that the engine over heated, and that was the main problem, not sure why the alarm didn't sound before it got that hot, but, now the clanking noise, is not good, you'll need to do a compression check and I would say a leak down test. That will tell you more about the condition of the cylinders, and hopefully figure something out. But the clanking noise is not good, especially after a massive overheat, whether that was caused by lack of water flow, which means the alarm should have sounded sooner, or lack of oil, which would make it get stupid hot stupid quick and potentially have some catastrophic damage :/ sorry to hear about that :(
Great analogy between marine & automotive RPM operating range. Ring Free Plus & Quickleen are a staple in anyones tool box. Hope everyone picked up the subliminal message ( Invest in the best testing equipment )leak down tester...lmao Another great tutorial.
Never had an engine blow up on the water. My Yamaha 150 is a 1994. It looks and runs great. But I often wonder if one day it might decide to “give up the ghost”. I have no idea how many hours it has on it because I did not buy it new.
Had a 05 DF250 blow a head gasket a couple years ago with very low hours. Heard (after the fact) that there were a handful of bad casting that year. The issue probably would've been covered under warranty if the original owner actually used the boat....
Never have had an engine blow up on my watch! Albeit, in 2003 I took my brother with the Boat Club of Costa Rica to a trek down the Sarapiqui River into the San Juan River in Nicaragua and from there to the mouth of the San Juan River into the Caribbean. On the way up stream to Costa Rica after 5 hours of battling the current my 1969 Chrysler 20 Hp overheated and we had to be towed within our country at least! Both of the cylinders scored and compression was established to 105 psi on the top cylinder and 108 on the Botton cylinder at operating temperature. The post mortem was blamed as an error of mine for not sealing the heavy duty water pump with form a gasket, which is not a normal procedure on the Workshop Manual. Yesterday I checked the compression cold-cold as I had no means to put the motor into a water drum and it had been recently fogged, and the compression was at 100 psi even. I imagine that I could get more hours of fishing enjoyment out of this motor before replacing the powerhead. I have one powerhead of such motor in storage...
How would you test button-start engines? Will the button not start the engine with the lanyard off? And when will it stop trying to crank an engine with no spark plugs?
All the test button does is allow you to momentarily jump the starter solenoid and turn the starter over, spinning the engine. The engine will only start if the plugs are in, the lanyard is on, and the key switch is in the one position. Then it will start the engine.
If you test the engine in water and it works well, is it necessary to do the compression test? It is a used 2001 150hp Mercury engine! And what would be a reasonable price for this engine?
If you are looking to buy it, I would definitely still do the compression test and it depends is it an opti or an XR6, either way, not more than a couple grand depending on the condition
So, you are saying that screwing in the comp. tester should only be done on 4 strokes? First time I ever heard that. What is the reasoning on this statement other than 2 strokes have lower compression? What happens if I screw in the comp. tester on my 2 stroke? Wrong reading? Please explain. Thanks!
Had an omc seadrive on a v20 and blew one cylinder but still made it back in on 3. Piston burned a hole threw. Don't miss 2 smokers. It's hard to trust those vro motors in the ocean.
I blew a piston on a V4 Evinrude 88 last year and just removed the wire to that plug and kept on running. Couldn't find a new motor till this summer so I ran a V3 Evinrude 66 the rest of the year! 😀 those old 2strokes are damn near bomb proof
Wait can't you use the same type of compression tester for a 2 stroke as well? It doesn't have to be the one with the rubber boot that you push in the spark plug hole right??
Came here for this too. I'm confused as I thought you could. But now I'm curious and want to hear the answer. I have the screw in type and was going to test my 2 stroke but now I am going to wait to figure out the answer
Yes. You can, theres no difference really, just another tool that makes the compression testing quicker, your screw in testers are fine and a little more accurate ;)
It will work on a two stroke if at tdc because at that point the piston covers all the ports and you will see if the rings leak. Thats all you will see not like 4 stroke where it can be piston rings or valves
Isnt carbon a problem only on direct injected engines? I know pretty much all cars that are direct injected they get carbon build up, and we end up with burnt valve seats, interesting to see that WOT is recommended to clear carbon on an outboard lol we sell decarb services on cars and what we do is we run a carbon cleaner through a vacuum port to get the back of the valves soaked and loosen up thag carbon
Rogelio Bravo Direct Injection does cause more carbon than throttle body/injectors. Typically, throttlebody or intake inject forms carbon on the valves whereas DI does the pistons and valves. Using additional chems like Sea Foam on a regular basis will keep carbon down. Hot soaking an engine with various products is a last resort.
@@PFLEONARDI0906 well i havent seen a gasoline engine that doesnt have a throttle body yet, i know they exist but i havent seen one yet, but arent all non direct injected engines port injected? Which means the valves usually get fuel sprayed behind them cleaning them in the process, when you have direct injection the injector is in the combustion chamber, which is why the valves get carbon build up on them, making them a problem
Yes, it's way more of an issue on direct injected engines. The carbon build up takes time, like you said, the fuel comes in and basically cleans the valves. But if the engine is ran for hundreds of hours at the low speeds is when the build up happens. Usually you'll see it a lot on rivers, places like the inter coastal and with people that do a lot of trolling. That's why the ring free and the quickleen are used to clean it off the valves, its basically the same thing as the decarb service you sell for the cars :) A another problem, (That I should have put in the video :/ amazing how much stuff you can forget when trying to cover a subject :( ) is getting cheap gas or using a lot of ethanol gas and having moisture in the fuel. The valves rust up and give a lot of leak down as well!
@@BornAgainBoating wow, i didnt know ethanol could be such a problem, lets say that you are using just regular pump gas, or premium gas but you always use your boat to almost empty the can, does that really become a problem then? Or do you have to strictly stick to E0 gasoline?
Hi... Thanks for the video... I just bought a 200 HP Johnson outboard. All the cylinders were psi tested to 100-110 except the top left read 40psi..... Any thoughts ideas would be greatly appreciated. Thanks...
Thank you for your question! Please post it in our Born Again Boating Community! Go here and scroll down to access - it’s free: www.bornagainboating.com/
I have a 150 pro v 80s model all but one cylinder is at 100psi one is at 95 I only way checking it wasn’t running right smoking more than it normally does and started overheating
I’ve been meaning to ask this question for some time. What kinds of checks, services, etc., should I do now on my 2005 Verado 250HP that has only 79 (yes 79) hours on it in 15 years. The boat is a Nitro 929, 21 foot bass boat being used only on freshwater lakes in Central Texas. Have never trolled. For various reasons, have not been fishing much for over 15years. I had the usual maintenance done such as water pumps, spark plugs, pencil coils, oil changes, FSM rebuild, etc. Motor runs good. Had it out today. Smart Craft gauges indicate good temps, pressure, etc. Want to use the boat more often now but am kinda concerned cause I understand that a big motor with such low hours might need some special attention now. Your video about compression test made me wonder. What do you recommend?
Not much else you can do! You said you've done the water pumps, plugs, coils, and fsm rebuild. There isn't much else that can be done! Youve done a good job already. I'd say to just use it and enjoy it! 2005, there might be a bell crank service bulletin for that engine, but that is still going to be warrants warrantable if it hasn't been done yet. And any mercury dealership should be able to get it done for you, since its a warranty issue.
Just did a conpression test on my 2007 175hp optimax, Starboard getting 90 on all 3, port side got 70 on top and 80 on both middle and bottom, should I be worried?
Great video! I just bought a 2002 115 Yamaha 4 stroke. No accurate idea of hours but according to previous owner around 500 hours. Compression is perfect in all 4 cylinders. No idea if there is any carbon build-up but would you recommend running the higher concentration of Ring Free now? Or just start using Ring Free every 2-3 fill ups?
Well be watching these vids for years and now I need help. I tested my 05 verado 250 with 760hrs on it. Get this all were the same but the issue is I'm at 135 psi each one. Motor has ran great and I get on plane no issues and she will hit 70 MPH and faster but can't drive it past the walk. Anyway, I see that brand new it says 180 psi. Do I have reason to worry? Thanks again for the years of videos. Hope ya see this. Edit, also can I use power tune on this motor as its never been done.
Many years ago before I knew any damn thing at all I blew up a Johnson 48spl by running ethanol gas with octane booster on it. Blew a hole right thru the block. Man that was dumb!
Yes, you can on mechanically controlled engines, it lets more air into the engine and gets you a higher compression number, but that doesn't work on digitally controlled engines :)
Can reed valves effect compression readings on a 2 stroke? I have a 1991 Johnson 225 that has 85 psi in all cylinders. Guess it’s tired? Thank you for the video.
Let my boat sit for a couple months when it was super cold. Put some fuel stabilizer in it and stored it. Brought it out to the dock and started up. As soon as I tried to throttle it up in the open it died. Shop says zero compression on cylinder 1. Any ideas on why and cost? Motor is 115 merc EFI 2008 4 stroke.
Quick question so on a two-stroke you have to use that type a compressor gauge with the rubber on the end? Because I did my compression test with the other one.😬
So I had a motor loose 10 mph this weekend and did a compression test and it had 120 on all cylinders except cylinder 2 and it had zero compression. Is it gone? Also after it lost lower I gained 10 psi in water pressure
Yes, the quicken from mercury is for all their products including mercruisers, idk much about diesels so you'll have to ask a diesel person for info on that ;)
For a 150 four-stroke, that does seem a little cold, depends on the water temperature though as well. And what's it go to after you run the engine for awhile at speed?
@@BornAgainBoating 120 all the time , the water is 72o here 84 in the Gulf it may be the gauge or the thermostat I guess . The gauges on this boat are Farria and they are pretty crappy ...none work but it reads the same thing on the instrument panel on my GPS ..
Dammit Ive seen alot of videos and they never mention removing the kill switch before testing if doing it that way. I thought it wouldn't try turn over withought kill switch? Was going to test myself pre purchase of a 2nd hand and buy the kit as mechanics are closed tomorrow and don't want this outboard to be sold if it's good
Hi I have a 200hp Yamaha 4stroke outboard the gearbox gives a cranking sound when on neutral and gets worse whenever the reverse is engaged pls what can I do
Take off the shift cable from the shift mechanism on the engine. Then manually shift the engine and see if the noise goes away while shifting manually. If it does, then you can adjust the shift cable, or replace it if it needs to be replaced. If it doesn't go away, you'll want to drain the lower unit oil and see what it looks like to make sure nothing is wrong with the lower unit.
@@BornAgainBoating I did drain the oil, it's all black and contains metal filing. And it's disturbing considering that I did the 100th hour service a week before.
So what does doing a leak down test on 2 stroke determine? My 3 cylinder is 90, 90, 75. I’m being optimistic on a head gasket starting to go. But with said test, the results wouldn’t tell you if it is gasket or rings? Would hear air coming from throttle body? Idk.
I was asked by somebody if I checked the compression on my 200 Yamaha and I said , no I'm going to the keys in five weeks and I want one less things to worried about , but the plugs all looked the same ..., can't same the same for the 40 Honda I'm dragging down there too
I’m trying to do a compression test my 03 Yamaha 25hp 4 stroke and I can’t even get a proper reading on the gauge , it will climb up on the gauge as soon as you hit the start button but will immediately leak back down to zero but it will start up just fine. All of the fittings seem secured and I don’t understand why I can’t get an accuracy reading. What would this mean ?
Pistons only creates pressure on top dead center level then lost the pressure immeditely as they are moving up and down. You are using a regular gauge but should have testing gauge which measure maximum pressure always and keep the measurement until you reset it manually from the button. Look at the gauges on the videos carefully.
Try to do a warm compression test, but if you can't then cold should be really close to the same numbers. You don't need to over do it with the tests though. A good engine will produce good compression readings all the time
Ring free treatment works great. I never believed much in mechanic in a can, but this stuff really works great.
I’m getting an 18hp 1960 Johnson 2 Stroke that we found in the back of my grandfathers shed. He upgraded to a 25 horse in the 70s and it hasn’t run since. Now that I’ve conquered my Mercury 250 EFI (knock on wood) I need a new challenge! Going to find a little panga or Jon boat to put it on for the bay when it’s too windy for offshore.
About a month ago had a mobile mechanic do compression test on a motor I just bought and it showed that it was low on all cylinders. I took it to a Evinrude shop and they tested it and they were all perfect. $250 down the drain for a bad test.
Quick tip, if the compression test is low, spray a good amount of oil in the combustion chamber then re test, if the compression is now high it means the ring are damaged if it's still low it means your valves are bunt out.
Thought you would have known this trick.
Irrelevant due to having a leak down tester to confirm the cause of low compression as he showed in the video.
@@scr454
Leak down test only tells you that you have blowby, does not tell you wear it's leaking, this method does.
@@anndivine9989 leakdown test supplies continuous air that can be heard or felt leaking from exhaust, intake, crankcase. He even says it in the video. Love that your informative, Google it.
WOW! "Thought you would have known this trick." WOW!
I had a 225 yamaha 2 stroke blow up when I was trying it out to buy. It ran perfect for a couple of miles and I figured it was good. I turned around and headed back in nailed it to get on plane and kapow... I did not buy it...lol and ring free stopped my 150 4 stroke from using oil badly, I could not believe it...thanks for your videos
Love the videos, wish they were out years ago. Got an old 40 hp merc collecting dust, rust and sun now because resources weren’t available then and local tech’s didn’t want to help because it’s a merc.
I had a reed valve break and ravage the inside of the motor. Not exactly explosive but did some pretty good damage
Here is my boat story, we were in our 42 invincible with quad 350s last year 30 miles offshore, one engine went out because it overheated, then we started to head back then another engine went out because of something in the bottom end, we started to get sketched out.. we were about 5 miles offshore and all the electronics shut off and it caused both the other engines to stop. Not a fun experience
I melted a 2.4 liter 200 merc when I was in high school. It overheated so bad that the pistons were stuck to the chrome bore. I also blew up an old v4 110 evinrude, the vro pump failed and it blew a window in the block.
I blew up a 2004 Evinrude 250 FICHT one time. My buddy called me to say the bite was on. I was low on gas had it full throttle and PUFF cylinder number 3. Blew a hole in the top of the piston. I always had an issue with that motor.
I would do a leak down test for a best results. but for a quick test to get a ball park area of problem your making short work of it with that test. I like your channel buddy! I've got educated with a Opti Max 225 in the past few months. your channel helped.
Hi Aaron, I always feel smart after watching your videos, even when I'm not fully understanding it all! ☺ But I am learning, and learning a lot!.... Thank you for all the work and effort you put in to your educational videos...
You can do it!
MAKE SURE YOU HAVE FULL THROTTLE AND FULL CHOKE ON!!!! I have personally seen 30% psi difference with these two conditions the other way (low throttle, choke off). This is especially true on older outboards I work on (60's and 70's).
I had a 2000 Yammy OX66 250 with 600hrs blow on me due to lack of fuel. Lost cylinders 2 and 4. Trade it for a used 2004 Yammy 300HPDI. Which also blew cylinders 2 and 4 due to a clog in the HP fuel pump basket filter. The HPDI, I resleeved / re built the cylinders and replaced the HP fuel pump. Now it's running fine. 👍🤞
I have a 115 Mercury EFI and shop said I have zero compression on cylinder 1. How much did it cost you to resleeve?
I did it myself...found a shop that had a junked motor. Torched and tapped out the used sleeves.
Great Video's Bloke . Just been through the cracked block scenario on a 115 susuki. Takes the wind right out of your sails . But a new Honda and Minn Kota take away alot of the sting though it hurts the wallet.
I did have an engine blow up on me. It was not an outboard but Wheelhorse mower. When the big boom comes from between your legs it's a bit scary!
twss!😜
I have never seen a outboard blow up in front of me always just the aftermath. Rods thru cases, wiring harnesses fused to the cases and heads. Motor got so hot I’m surprised it didn’t melt the cowling.
Had my 200 Ocean Pro eat a ring and spit it out at 810 hrs. Took out a piston and a head. Was told it was a carbon buildup. Had the power head rebuilt, running great now lots of power and it’s a thirsty 2 stroke.
Had the same happen on a V4 Evinrude 88
Soooo... what's the story with the engine fire at 2:45? :)
Lol test drive, ignition coil shorted out and caught the wire harness on fire! Engine started over heating and then I saw the smoke :( had to let the smoke slow down, (in case of a fuel leak) to help smother itself out, then pulled the cowling and just patted the rest of the fire out with the rag lol that was an interesting ride first thing in the morning lol
I was 10 when my dad bumped me off at the river. I turned the key for the first trip after a long river and saw people waving their arms and screaming at me to turn around.. apparently the fuel hoses had dry rout and the engine caught fire very quickly. I was able to douse the engine using a 5 gallon bucket and Pauling water. The worst part really was paddling the boat up current to get back to the ramp. Lol
I have 1986 force 125 getting 140 psi in each cylinder running strong!!
Basically 2 strokes can last a hole lot longer then 4 strokes.
Not trur
Exactly right. . That is why they are phasing two strokes out. . They last too long. . Everything is becoming disposable. . Years ago fridges lasted 30 years now you’re lucky to get 5 years out of a fridge.
The more parts that make up any machine means there are more parts that all have to be working together in sync. Every moving part has only so many moves in it before it fails.
What that means is that there are many more parts working their way to eventual failure in a complicated machine like a 4-stroke.
Love it!🙂👍🏻👏🏻👏🏻👏🏻👏🏻👏🏻👏🏻
Should you test compression a 2 stroke with WOT?
Not really, ive never tried it but I don't think it will change the readings on a 2stroke :)
I had a Merc 135 2-stroke outboard blow up real good. Crankshaft bearing failed. Much money was spent on a reconditioned crank, bearings, and the lower pistons and rings. 15 years later it is still running fine as it ever did. I can't sell it though, because as soon as people hear it had major work they don't want it. So I guess I am doomed to keep it until it dies. Could be a while though, I just did a cold compression test and I have between 102 and 109 psi in all cylinders, the two pistons that were replaced being the higher ones. Oh well it keeps me from dropping $50 grand on a new boat.
I did have a race kart engine and a Seadoo 787 blow on me while driving it. Detonation was the culprit on both. My ear suffered even with a helmet on in the kart. The head was curved up and the rod bent. That was when I was 12 yo. The 787 2 smoke ran on race gas. A friend who went to the race with me thought he was doing me a favor and put the wrong fuel in while I was in the head. Believe me, I came out the hole ahead of everyone and it ran so fast down the the front straight. I was going wow in my head and then boom just before the first turn buoy. LOL Towed in...oh well, lessons learned.
I have a 1975 70HP Johnson 4-Stroke I recently picked up and did a compression test. All three cylinders read 125-130. But is it normal for the tester gauge to go down or is that another issue with the motor? Thank you.
I have an early '90's 175HP mercury outboard on my 1993 23ft trophy Bayliner. Omw to Catalina island one of the ears on the prop broke off. It gave me alot of vibration and with less than 10miles to go, I decided to keep going at low RMP And low speed of (10MPH). I got to the island and putted around, fished for a few hours and decided to head back to San Pedro (25miles). After 15miles my engine completely shutoff . Got towed back to my slip and tried to start the motor and had no spark anywhere. Did a compression test and all read 65psi. Now I'm looking to repower my boat. 😫😫
Bought a 2001 merc 150 cxl 2 stoke 8 years ago. Compression test back then said 85psi on all 6 cylinders. We checked it with 2 testers and got the same results. Based on your info, i should have passed on the engine. 8 years later, it has the same numbers and same performance as it did when I bought it. Thoughts?
For an older 2-stroke like that, 85 is still a little low, normally that type you will see around 90-105PSI, but there are other factors to consider, like the starter and the battery and the power cables to the engine.
As long as all the cylinders were 85, I wouldn't think to much into it either, 8 years of run time and who knows how many hours, engines obviously got no issues with it :)
A lot of compression tests you want to make sure there isn't a difference between cylinders, they just give you an over all view of the mechanical health of the engine :)
@BornAgainBoating thanks for the reply. Unfortunately, i don't have an hour meter on this one and it has no computer to tell me. Merc doesn't provide numbers to look for except that they should be consistent. As long as it runs, we'll enjoy it. Plenty of power for my 20' Proline.
I blew up a 99 mariner 50hp 4 stroke a couple weeks ago, blew out all the oil and had a piston rod go through to block
When doing a compression test on my 150HP 4 cylinder verado, do I need to take all the spark plugs out so I don’t risk the engine firing up when in key start the engine? Or can the other spark plugs stay in while you check the one cylinder? Thanks
Just had an incident with my Yamaha F150. I was on my way out on a trip and felt a loss of power so I went to neutral to check the engine and as soon as I came to a stop I saw smoke coming from my cowling. Turned the boat off just as the warning sensor came on. After pulling the cowling, I saw some oil pray on the engine was causing the smoke, so I got towed in. Once I got towed in I saw one bolt came loose from the manifold. Now I got a clanking noise coming from the engine after fixing the bolt issue and refilling my oil.
Ouch! Well, that's not good my friend, not sure what caused the lose bolt issue, but the spraying oil and creating smoke, that means the engine was hot enough to burn the oil to make it smoke when it hit the engine. Which most likely means that the engine over heated, and that was the main problem, not sure why the alarm didn't sound before it got that hot, but, now the clanking noise, is not good, you'll need to do a compression check and I would say a leak down test. That will tell you more about the condition of the cylinders, and hopefully figure something out. But the clanking noise is not good, especially after a massive overheat, whether that was caused by lack of water flow, which means the alarm should have sounded sooner, or lack of oil, which would make it get stupid hot stupid quick and potentially have some catastrophic damage :/ sorry to hear about that :(
Great analogy between marine & automotive RPM operating range.
Ring Free Plus & Quickleen are a staple in anyones tool box.
Hope everyone picked up the subliminal message ( Invest in the best testing equipment )leak down tester...lmao
Another great tutorial.
Well said!
Never had an engine blow up on the water. My Yamaha 150 is a 1994. It looks and runs great. But I often wonder if one day it might decide to “give up the ghost”. I have no idea how many hours it has on it because I did not buy it new.
Had a 05 DF250 blow a head gasket a couple years ago with very low hours. Heard (after the fact) that there were a handful of bad casting that year. The issue probably would've been covered under warranty if the original owner actually used the boat....
Great video , my brain hurts from all the educational information you guys give. Feels good! Lol. Keep em coming. 😎🌴 stay safe!
Our pleasure!
Never have had an engine blow up on my watch! Albeit, in 2003 I took my brother with the Boat Club of Costa Rica to a trek down the Sarapiqui River into the San Juan River in Nicaragua and from there to the mouth of the San Juan River into the Caribbean. On the way up stream to Costa Rica after 5 hours of battling the current my 1969 Chrysler 20 Hp overheated and we had to be towed within our country at least! Both of the cylinders scored and compression was established to 105 psi on the top cylinder and 108 on the Botton cylinder at operating temperature.
The post mortem was blamed as an error of mine for not sealing the heavy duty water pump with form a gasket, which is not a normal procedure on the Workshop Manual.
Yesterday I checked the compression cold-cold as I had no means to put the motor into a water drum and it had been recently fogged, and the compression was at 100 psi even. I imagine that I could get more hours of fishing enjoyment out of this motor before replacing the powerhead. I have one powerhead of such motor in storage...
How would you test button-start engines? Will the button not start the engine with the lanyard off? And when will it stop trying to crank an engine with no spark plugs?
All the test button does is allow you to momentarily jump the starter solenoid and turn the starter over, spinning the engine. The engine will only start if the plugs are in, the lanyard is on, and the key switch is in the one position. Then it will start the engine.
If you test the engine in water and it works well, is it necessary to do the compression test?
It is a used 2001 150hp Mercury engine! And what would be a reasonable price for this engine?
If you are looking to buy it, I would definitely still do the compression test and it depends is it an opti or an XR6, either way, not more than a couple grand depending on the condition
04 150 ficht v6 Top: L - 105 psi R - 110 psi Mid: L - 105 psi R - 105 psi Bot: L - 105 psi R - 105 psi Is this a sign of a healthy test?
2 / 18 / 20
Idk what that means :(
Yes. Those compression readings look good!
Born Again Boating are you able to tell me why the top right cylinder is the only one thats 110 psi
On 2stoke do you see a different psi on a cold motor over a warm motor.
You can yes, but not a massive amount.
So, you are saying that screwing in the comp. tester should only be done on 4 strokes? First time I ever heard that. What is the reasoning on this statement other than 2 strokes have lower compression? What happens if I screw in the comp. tester on my 2 stroke? Wrong reading? Please explain. Thanks!
Had an omc seadrive on a v20 and blew one cylinder but still made it back in on 3. Piston burned a hole threw. Don't miss 2 smokers. It's hard to trust those vro motors in the ocean.
I blew a piston on a V4 Evinrude 88 last year and just removed the wire to that plug and kept on running. Couldn't find a new motor till this summer so I ran a V3 Evinrude 66 the rest of the year! 😀 those old 2strokes are damn near bomb proof
I have a mercury outboard 50 hp blow piston and ring was mixing water and oil now is a total rebuild
Always great info.
Glad you think so!
Wait can't you use the same type of compression tester for a 2 stroke as well? It doesn't have to be the one with the rubber boot that you push in the spark plug hole right??
Came here for this too. I'm confused as I thought you could. But now I'm curious and want to hear the answer. I have the screw in type and was going to test my 2 stroke but now I am going to wait to figure out the answer
Yes. You can, theres no difference really, just another tool that makes the compression testing quicker, your screw in testers are fine and a little more accurate ;)
@@BornAgainBoating Thank you!
Once again every video I learn something new thank you very much
My pleasure!
can you show us how you did hook-up the remote starter ? Thanks
send the gauge back to snapon lifetime warranty worth a try good add for them. I've iearned a lot from your shows thanks
That Ted Williams is a CLASSIC Aaron! Very cool
Air cooled :) lol I've had to get that engine running more than once lol
So if I understood right, the compression test must be done on full throttle only?
Melted a 140 Suzuki 2 stroke straight to hell🔥
Thank you so much for sharing this !!!.
No problem 😊
Are leak down tests relevant on 2-smokes or is that just a 4-stroke thing?
It will work on a two stroke if at tdc because at that point the piston covers all the ports and you will see if the rings leak. Thats all you will see not like 4 stroke where it can be piston rings or valves
Thanks for the content, learning a lot.
My pleasure!
I have an old 1980 Chrysler 100hp with 150psi on all cylinders. I assume this is fine?
I'd say yes!
Born Again Boating good to know. Thanks :)
Do you have to use rubber boot when testing 2 stroke? Or can you use the screw in adapter?
You can use the screw in, rubber boot just makes quick and easy :)
Isnt carbon a problem only on direct injected engines? I know pretty much all cars that are direct injected they get carbon build up, and we end up with burnt valve seats, interesting to see that WOT is recommended to clear carbon on an outboard lol we sell decarb services on cars and what we do is we run a carbon cleaner through a vacuum port to get the back of the valves soaked and loosen up thag carbon
Rogelio Bravo Direct Injection does cause more carbon than throttle body/injectors. Typically, throttlebody or intake inject forms carbon on the valves whereas DI does the pistons and valves. Using additional chems like Sea Foam on a regular basis will keep carbon down. Hot soaking an engine with various products is a last resort.
@@PFLEONARDI0906 well i havent seen a gasoline engine that doesnt have a throttle body yet, i know they exist but i havent seen one yet, but arent all non direct injected engines port injected? Which means the valves usually get fuel sprayed behind them cleaning them in the process, when you have direct injection the injector is in the combustion chamber, which is why the valves get carbon build up on them, making them a problem
Yes, it's way more of an issue on direct injected engines. The carbon build up takes time, like you said, the fuel comes in and basically cleans the valves. But if the engine is ran for hundreds of hours at the low speeds is when the build up happens. Usually you'll see it a lot on rivers, places like the inter coastal and with people that do a lot of trolling. That's why the ring free and the quickleen are used to clean it off the valves, its basically the same thing as the decarb service you sell for the cars :) A another problem, (That I should have put in the video :/ amazing how much stuff you can forget when trying to cover a subject :( ) is getting cheap gas or using a lot of ethanol gas and having moisture in the fuel. The valves rust up and give a lot of leak down as well!
@@BornAgainBoating wow, i didnt know ethanol could be such a problem, lets say that you are using just regular pump gas, or premium gas but you always use your boat to almost empty the can, does that really become a problem then? Or do you have to strictly stick to E0 gasoline?
Hi... Thanks for the video... I just bought a 200 HP Johnson outboard. All the cylinders were psi tested to 100-110 except the top left read 40psi..... Any thoughts ideas would be greatly appreciated. Thanks...
Thank you for your question! Please post it in our Born Again Boating Community! Go here and scroll down to access - it’s free: www.bornagainboating.com/
I have a 150 pro v 80s model all but one cylinder is at 100psi one is at 95 I only way checking it wasn’t running right smoking more than it normally does and started overheating
I’ve been meaning to ask this question for some time. What kinds of checks, services, etc., should I do now on my 2005 Verado 250HP that has only 79 (yes 79) hours on it in 15 years. The boat is a Nitro 929, 21 foot bass boat being used only on freshwater lakes in Central Texas. Have never trolled. For various reasons, have not been fishing much for over 15years. I had the usual maintenance done such as water pumps, spark plugs, pencil coils, oil changes, FSM rebuild, etc. Motor runs good. Had it out today. Smart Craft gauges indicate good temps, pressure, etc. Want to use the boat more often now but am kinda concerned cause I understand that a big motor with such low hours might need some special attention now. Your video about compression test made me wonder. What do you recommend?
Not much else you can do! You said you've done the water pumps, plugs, coils, and fsm rebuild. There isn't much else that can be done! Youve done a good job already. I'd say to just use it and enjoy it! 2005, there might be a bell crank service bulletin for that engine, but that is still going to be warrants warrantable if it hasn't been done yet. And any mercury dealership should be able to get it done for you, since its a warranty issue.
Thanks for your quick response!! Want you to know that of all the How-To videos out there, yours are the most concise and clear ones - in my opinion.
Just did a conpression test on my 2007 175hp optimax, Starboard getting 90 on all 3, port side got 70 on top and 80 on both middle and bottom, should I be worried?
Great video! I just bought a 2002 115 Yamaha 4 stroke. No accurate idea of hours but according to previous owner around 500 hours. Compression is perfect in all 4 cylinders. No idea if there is any carbon build-up but would you recommend running the higher concentration of Ring Free now? Or just start using Ring Free every 2-3 fill ups?
How about using Seafoam in a marine application ?. Anyone have any advice ?.
I dont have much experience with seafoam, generally stick to the oem additives :)
Well be watching these vids for years and now I need help. I tested my 05 verado 250 with 760hrs on it. Get this all were the same but the issue is I'm at 135 psi each one. Motor has ran great and I get on plane no issues and she will hit 70 MPH and faster but can't drive it past the walk. Anyway, I see that brand new it says 180 psi. Do I have reason to worry? Thanks again for the years of videos. Hope ya see this. Edit, also can I use power tune on this motor as its never been done.
I get 91 and 98 psi on my Johnson 50hp. Is that too low? What’s a good range? Thanks!
Many years ago before I knew any damn thing at all I blew up a Johnson 48spl by running ethanol gas with octane booster on it. Blew a hole right thru the block. Man that was dumb!
Techron best for cars, OEM stuff for boats hands down
The WoT method during the ride in do much for 2 strokes? Or just 4 strokes?
I’ve always heard your supposed to hold it wide open and test compression is that not true?
Yes, you can on mechanically controlled engines, it lets more air into the engine and gets you a higher compression number, but that doesn't work on digitally controlled engines :)
Can reed valves effect compression readings on a 2 stroke? I have a 1991 Johnson 225 that has 85 psi in all cylinders. Guess it’s tired? Thank you for the video.
Let my boat sit for a couple months when it was super cold. Put some fuel stabilizer in it and stored it. Brought it out to the dock and started up. As soon as I tried to throttle it up in the open it died. Shop says zero compression on cylinder 1. Any ideas on why and cost? Motor is 115 merc EFI 2008 4 stroke.
instead of running WOT for 10 minutes could you just run at normal cruise speeds for like say 15 minutes?
They like to run wide open every now and then ;)
Can you just unplug primary side of coils instead of grounding spark plugs?
Any ideas on why a 200 hp suzuki 2 stroke could have 0 psi in one cylinder? Thanks
Head gasket or catastrophic failure. Do a bore scope. Of no obvious damage. Do head gasket
Head gasket, piston rings, or catastrophic failure :/
Thanks for the info!
how do you feel about marvel mystery oil as a fuel additive ... i put 32 oz per 50 gallons of gas, no other additive
Idk, I don't have any experience with it lol :)
Quick question so on a two-stroke you have to use that type a compressor gauge with the rubber on the end? Because I did my compression test with the other one.😬
No, either or is fine. I was just trying to show the options and a quicker way to do it :)
Born Again Boating got it thank you 😊
So I had a motor loose 10 mph this weekend and did a compression test and it had 120 on all cylinders except cylinder 2 and it had zero compression. Is it gone? Also after it lost lower I gained 10 psi in water pressure
Sorry, I want to know how to test the oil pump in the Mercury 150 hp optimax engine.
Can any of these carbon clean products meant for 4 stroke outboards be used for I/O engines?
Yes, the quicken from mercury is for all their products including mercruisers, idk much about diesels so you'll have to ask a diesel person for info on that ;)
Question my 150 temperature gauge reads 120 after warm up and hangs there + - is that too cold ?
For a 150 four-stroke, that does seem a little cold, depends on the water temperature though as well. And what's it go to after you run the engine for awhile at speed?
@@BornAgainBoating 120 all the time , the water is 72o here 84 in the Gulf it may be the gauge or the thermostat I guess . The gauges on this boat are Farria and they are pretty crappy ...none work but it reads the same thing on the instrument panel on my GPS ..
Dammit Ive seen alot of videos and they never mention removing the kill switch before testing if doing it that way. I thought it wouldn't try turn over withought kill switch? Was going to test myself pre purchase of a 2nd hand and buy the kit as mechanics are closed tomorrow and don't want this outboard to be sold if it's good
My 07 115 2 stroke Yamaha all 4 cylinders is 125 psi
Hi I have a 200hp Yamaha 4stroke outboard the gearbox gives a cranking sound when on neutral and gets worse whenever the reverse is engaged pls what can I do
Take off the shift cable from the shift mechanism on the engine. Then manually shift the engine and see if the noise goes away while shifting manually. If it does, then you can adjust the shift cable, or replace it if it needs to be replaced. If it doesn't go away, you'll want to drain the lower unit oil and see what it looks like to make sure nothing is wrong with the lower unit.
@@BornAgainBoating I did drain the oil, it's all black and contains metal filing. And it's disturbing considering that I did the 100th hour service a week before.
So what does doing a leak down test on 2 stroke determine? My 3 cylinder is 90, 90, 75. I’m being optimistic on a head gasket starting to go. But with said test, the results wouldn’t tell you if it is gasket or rings? Would hear air coming from throttle body? Idk.
It's your rings/ cylinder wear
Very nice video . And great tip.
Thanks a lot
Im missing tech Tuesday intro!
Same !
I have a 2001 johnson OP 150 and cruise at 3000 to 3500 rpm @ 28 to 32 mph is that good or bad!
Open her up every once in awhile! Let her breathe!
Yeah, that's good. Don't forget to hit wide open every now and then and let it breathe like Mike said :)
Thanks guys
I’m starting to Dislike Tuesday’s because it makes more things for me to check
I was asked by somebody if I checked the compression on my 200 Yamaha and I said , no I'm going to the keys in five weeks and I want one less things to worried about , but the plugs all looked the same ..., can't same the same for the 40 Honda I'm dragging down there too
LOL.. sorry man!
Lol ikr?! Same here I've got 3 outboards now 🤦♂️ and an I/O
Dads engine blower up, water pump went bad and just started smoking
I’m trying to do a compression test my 03 Yamaha 25hp 4 stroke and I can’t even get a proper reading on the gauge , it will climb up on the gauge as soon as you hit the start button but will immediately leak back down to zero but it will start up just fine. All of the fittings seem secured and I don’t understand why I can’t get an accuracy reading. What would this mean ?
Pistons only creates pressure on top dead center level then lost the pressure immeditely as they are moving up and down. You are using a regular gauge but should have testing gauge which measure maximum pressure always and keep the measurement until you reset it manually from the button. Look at the gauges on the videos carefully.
Can you just unplug the fuel line?
Do you do cold compression check then hot compression check? What would you recommend?
Should I do a cold compression and hot before seafoam then another cold hot compression check after sea foam video?
Try to do a warm compression test, but if you can't then cold should be really close to the same numbers. You don't need to over do it with the tests though. A good engine will produce good compression readings all the time
Comments are particularly interesting on this video
Great info.
Thanks for watching!
How long have you been a marine technician?
10 years :)
Wow awesome and you seem to love the career.
great channel!!!
Glad you enjoy it!
Pretty good boys
Great Video
Thanks for the visit
Is the a cleaner for 115 evinrude etec
I think evinrude calls their stuff carbon guard, shop.evinrude.com/products/343711/Fuel_Additives
good work
Thanks for the visit
I blow engines up like it's a popular thing to do