Man I have quickly become addicted to your channel, this is rad ass content and the vlog style going to buy then fixing is making them all hits. Congrats 👏
Love your channel I’m a new subscriber, if I could make 1 suggestion I would bring some tools when you go look at these bikes on the get go and pull the plugs and bore scope them yourself:)
Watching this shows something important that I need to work on for myself: treating each task as a voyage of discovery instead of a major catastrophe. Total zen. No stress. Well done.
Im 42 and been watching your videos for past month... I cant stop. I am working on my sons atv and I can relate a bit. Your content is so good... I made my 12 year old son watch it with me and now his addicted too. Thank you for not cursing in your videos, even when you hit the bottom end. I would not be able to keep my cool like you do considering the problems you face here and there.
I've said it before I'll say it again. I love how calm and methodical you are. I wish I could be mire like this when I get into projects especially when unexpected problems arise. Looking forward to the 300 being finished as well. As for this I'd go big bore. You have more proof of work than almost any reseller. You should be able to get a premium for this when it's all said and done. Keep up the great work.
I like his calm too but I want to throw stuff when he repeats himself 5 different time. Roll forward back stuck on something. Starter stuck on something. Manual roll stater 3 times stuck on something. Choose top or bottom end to open up. Pull spark plug where is it hung up.
If I had to guess. It was a chain reaction of events. First started by the lexx pipe and cdi box upgrade. More exhaust flow due to enlarged pipe and adjusted fuel map due to cdi upgrade Which in turn allowed to rev higher and floated a valve. In turn piston meets valve and boom bob's your uncle. The hole in the piston is from the valve stem giving it a little pokey pokey. Imo. I'd go back to stock. This particular machine is very robust right from factory. After market parts destroy machines at least in my experiences. For general all purpose riding, stock is the way to go. Just my opinion.
Do you think there's some of that piston in the bottom end still it would suck to go through all that trouble and have a piece of the piston get sucked up in the bottom end I think it should get a whole tear down and inspection
No he can't figure out valve float He can't even figure out how it over revved And bent the valve breaking it off he's looking and saying stupid things like it didn't get enough oil.. every bent valve in history is from over-revving 94% of the time
I have the same bike. The seller did the same thing to me…..said he was riding it and it just stopped. Told me it was the solenoid stopping it from turning over. Paid “$1,700”for it…..must be the scammers price for exploded 700’s. Hope you put out more tutorials so I know how to repair this thing. Up until your video no one has put anything online about the Honda 700xx.
Get a boreascope and take it with you on your inspections. It's a great tool that will save you thousands and help the seller to remember what really happened to it. 🙂 It will also give you way more leverage on the amount you are willing to pay. You might have been able to get it for $900 - $1000. If they won't allow you to scope it just walk away you'll be doing yourself a favor. You will know they are hiding something!!!! Great teardown and assement back at your shop.
@@billhartsfield424 I was just going to say. Plus, if you have a hole in the piston, who knows what little bits of metal went through it and are wedged somewhere, just waiting to be dislodged by the vibrations of a running engine.
Don’t forget to look in the bottom end for that little chunk that came from the hole in the piston. That could cause problems after a rebuild. Keep up the good work.
Since the valve broke, the bottom end is damaged. The connecting rod bearing for sure should get replaced. If I did this I would rebuild entire engine, probably all bearings and seals plus anything worn. The camshaft with a flat spot is beginning to fail, it should be replaced. My experience working on all different types of engines is that when there is broken metal in the engine, inside the oil it ends up in the bearings, gear teeth, anywhere oil goes. Those items likely should be replaced. Usually this guy's repairs are sound, his thoughts bottom end is ok are way off. The piston had a hole in it ... where did the metal go? The crank stopped turning ... the force or piston coming to abrupt stop .... what parts saw those extreme loads? Were they designed to take it?
Awesome video man. Good luck with the rebuild. I'm not familiar with trx700 but I've seen that kinda damage from downshifting instead of upshifting. Engine spins to fast, valve springs can't keep up and piston makes contact with the valves. At least it's in good hands now.
Dude if you're someone who knows what you're doing as you do, this is 100% worth the rebuild on one of these. Especially if you're getting any deals on parts.
When you're getting a good deal you have to assume the worst and not take seller info at face value. That usually works in your favor except for when it doesn't. When it doesn't, we get some great content and a real world idea of the risks associated with "needs work".
He knew that it had catastrophic failure he just wanted to unload it and hope that he could get somebody to buy it and take it without too many questions he's not an idiot even if you're not mechanically inclined you know when something don't look right like a spark plug
Throw everything at it, big bore stage 3 , hot cams. New power commander. This is where you get your revenge on that dam turbo. Keep this quad Joe, now you have to room to run something that’s gonna be that fast.
I think this machine would be worth it to do a complete rebuild. They are somewhat rare and would be great to add to a collection. Value in my area is between $7K-$8K. Even if you put several thousand into it, it's worth it.
If you're getting $7k-$8k in your area let me know where you're at. I'll send them to you all day long for $6k, you can make a nice profit and so can I!
I think you should do a complete engine rebuild. Why? Because I am doing that same thing on my 700xx and I could use all the help and advice. LOL! I had metal shavings in the bottom section.... My cam bearing(s) failed and caused huge damage. Can't wait for the followup videos on this. Great job!
Yeah you can look up the OEM part and see that its heat treated on the top like that so I don't think the crank overheated, guessing broken woodruff key on the flywheel or something and skipped timing.
Also check your oil reservoir in the bottom there's two screens in the hoses that go in sometimes when you replace the o-rings in it you bend those screens and you don't get oil flow to your motor you restrict it and they clog up and everybody forgets about them so you might want to check those out too the black oil reservoir canister the screens are built into the hose on the bottom
Glad to see this on your channel. I bought one in March and it's a beast. I bet it ran low on oil. I gotta add oil every few hours on mine. Fun watching you fix just about anything.
you shouldnt have to might wanna get that checked out before it ends up like his or atleast make it easier on yourself i have to fill my ltz 400 because the case it cracked so i know how it feel
Bummer, I would have never drove so far to pick up a bike that didn't run. Especially one where the engine was locked up. Too bad, cause it's a good lookin' bike. I didn't even know Honda made one-cylinders that big... Reminds me of the legendary two-stroke 500cc "Quadzilla" that Suzuki used to make. They were simpler, and were a bit easier to work on though. Those were wicked awesome bikes! I wish you the best of success buddy, I know you'll be able to make this one into a runner. Who knows, maybe you'll find some cheap parts and you'll ultimately break even! I wish you well, and peace out from Quebec, Cheers! :P
WOW that is an insane amount of carnage. Usually you see that kind of damage in a multi cylinder engine that keeps running, but a single cylinder engine normally dies before they're damaged that badly. Crazy!!
I think I would take the entire engine out of the frame and rebuilt it the best proper way you can. Obviously new bearings, new cylinder, new piston and rings and I would even install a new cam. Costly...yes, but than you will have a near new engine you can rely on for a long time... JMHO Thumbs Up!
Connecting rod stretched? Overheated wicked bad at high r's. Multiple points of failure. My theory. Definitely big bore with stage 3 hot cams. My take. Excellent video thanks for taking us along
Loving your channel!! Watching your shows everyday lately. I’ve grown up with motorbikes so it’s great to be learning so much about the inner workings!! Thanks for sharing . Keep doing what your doing 👌Reuben from Queensland Australia
Great video Joe go for a big bore it should elevate the valve issue as common problem on this model investing in a big bore is the route I would go but get feedback of others aswell and see what works best for you have a great week mate look forward to the rebuild video 📹
@@mattsloop2736 Kerosene is probably great for carbon build up, sludge, oil, whatever soft thing you wanna erase, but I don't think it will work great on any metal pieces that might have already ended up at the bottom end.
@@mattsloop2736 Well sometimes the old ways are still the best. Sometimes the car/motorcycle isn't worth spending too much money on it until you're sure it can be saved. Look at the cool channel NoNonsenseKnewsHow, the dude often use diesel to clean or unseaze old rusty cylinder in rusted old cars he's trying to start up after decades.
People upgrade pipes and compression and all kinds of things on four-wheelers and every other kind of moter I just think they were ripping on it riding the wheels off of it and not maintaining it and maintenancing it the way you're supposed to and checking it out when you hear noises and making sure everything's okay that's why it failed you can't ride the wheels off of it and not maintenance it I know this video is old but great video and God bless
piston hitting valve.. is usually a good idea to replace rod / bottom end too... With the force of the impact, It has more than likely affected the rod / big end bearing... So basically your looking at a FULL rebuild... Bottom end, Piston, Barrel, Head etc... I'd never take my chances and keep that bottom end in there now...
I have decided that the next dirt bike or quad that I buy, I will take Joe with me, because he gets these good deals everyday. I don't know how he does it. Great Video as always Joe.
Build it back to Oem, also loose the "tuning" box, together with bad maintenance (old and not enough oil!) probably the cause of failure! The seller was FOS anyhow, but you'll fix it like always!
^^This. If you're racing and already plan to rebuild the engine on a regular schedule, fine, go wild with the upgrades. But the vast majority of owners should just keep the thing stock. Say you do a "big 3" upgrade and you gain 10% peak horsepower...the reality is you're pushing that engine much closer to its limit. Honda's engineers knew exactly what they were doing when they designed that engine, and they deliberately built in that 10% as design margin. Anything you do to reclaim that extra power comes at the cost of reliability.
If it were me, I would be splitting those cases and looking for any metal chunks. Clearly there is atleast one decent sized one in there somewhere cause of the hole in the piston. The crank rod looked like it had too much side to side movement as others have said so I would do a closer inspection of that. At a minimum given the money your going to put into it with a new head, cylinder, piston, rings, cam and chain, I would think you would atleast want to spend the little extra money for bottom end gaskets to ensure there are no metal chunks floating around down there. It would also allow you to do an inspection of the transmission while you have it split. It would really suck to put all that money into it just to discover something else was messed up that you could have taken care of cheap.
I believe it had to do with the mapping system he put on it with the pipe. It most likely increased fuel/air mixture beyond the specs. Just my thoughts.
everyone holds the throttle open , and lets the motor run against the rev limiter , that may have caused the problem , or if that part of the cdi box was bad , just a thought. Great content👍
I have an 08'. I was thinking about messaging you to see if you were interested, but I live in Illinois mid state. These quads are beasts! The independent rear end definitely makes a difference in getting over stuff and uneven terrain. You fix it you're probably gonna wanna keep it!
Judging from cam and broken valve. My guess would be over tightened valves causing valve to kiss piston and wear out cam. Can't wait to see this one run. I didn't know they made a 700cc. Nice find. 👍
Got a 3 year old Polaris 1000 xp v twin in right now, dropped valve in cylinder 2, guy kept riding. To limp it back to his trailer by then it was toast. Gonna be about a $2500 rebuild if I find everything it it needs. Even roasted fuel injection. Polaris wouldn't touch it, would slap in new engine that's it. Would be around $5500 for that. Keep up the good work. Love the dog, mine don't like the shop she just chills out front all day. Unless it's freezing.
Ouch, that sucks. Hindsight, it looks like if you pulled the spark plug, you would have noticed it was mechanically re-gapped Edit: Clearly I posted this before getting to the end of the video, sorry lol
Could someone have taken it way past red line to float a valve or two so when the piston came up it hit a valve which broke causing all the damage? I like the way you do your diagnostics,you’re easy to follow!
HIs diagnostic skills are a lot to be desired, it drives me nuts😂 and I've done this for many years I don't know how many times I can watch him except for the screw-ups. And comedy.
this answer is correct. And with the after market mods grenadeing this machine, it was also run extremely hard, beat up from the street up. It's one thing riding fast, but they were raw dogging it, that's why they were modding it, so they can beat it harder.
It’s so good for you to know your way around these machines and for you to be able to give it a look over and then go with your instincts on what you believe is wrong with it. It’s too bad that you can’t trust anyone when it comes to people selling stuff because when it comes to money, you can’t trust a god damn thing that comes out of a person’s mouth. People will just beat on their stuff and break it,then they’ll have the nerve to tell you that it only needs the carb cleaned or something like that. Once you get into tearing down the engine, you come across something that’s one step away from catastrophic failure!
Awesome video. I always enjoy the work you do on quads. This particular one...well, it sucks how bad it is. As for me, if I'm keeping it, I go big bore kit no doubt. It sounds like you're wanting to sell it after its fixed so knowing these machines are beasts in stock form, why pay the extra money into an already expensive project?? Can't wait for part 2 and see it all come together.
I'd definitely would install with the big bore kit, somehow I would feel more justified with the rebuild.. I would definitely call the original owner up letting him know what a great guy he is..
Love you videos. Thanks for raising the value of my 700xx I swear no one knows about these gems. I just snapped the crank in mine last night so it’s funny this just popped up on my feed. Please let us know if you find cause I’ll be searching for mine!
You should really invest in your own borescope and bring it along with you while checking over these ATVs. Especially if the listing says the engine is locked up or not rotating. Simple enough to pull the spark plug and see for yourself what happened internally. Even just pulling the spark plug would have been a huge red flag, and from there, you could negotiate the price down even further. Probably wouldn't hurt to do your homework before purchasing on the price of replacement parts, based on what you know from the ad. Even if it didn't need everything listed, once you found the damage you could do some quick calculations and go from there. If the seller isn't willing to let you do at least that, walk away. He definitely knew something internal had let go, why else would he mention that someone else had borescoped it before you came along? As someone else mentioned further down in the comments, I would definitely check the flywheel key during the rebuild. If it sheared, it could have very easily skipped timing.
That’s a really good thing that I’m sure not many people would think about. And super useful in his situation with buying stuff that needs work weather it’s running or not.
Here is what I think happened, the small coolant hose you seen at first that was leaking caused the owner to add coolant from time to time. He neglected to put coolant in on a regular basis and the head cracked causing the coolant to leak into the crank case. Due to that happening, caused the oil to lose it's lubricity and not keep the valves running smooth and lubed, in turn heating up the components in the head, also visible by the discoloration, and eventually dropping the valve causing the carnage you know see.
New Subscriber here! If I had to take a wild guess, there might be a deficiency in the spring tension with the factory valves. They might not have enough spring tension to place on the valve, causing them to float, especially after it's heated up. Maybe there is an aftermarket valve train assembly you can get for it.
When you bend valves at high RPM the valve can break and when it does this is what you get. Why did it come out of time in order to bend? Tensioner. Plain and simple. You should also get into the bottom end, it rarely ends well when you put a hole in the piston. The bearing gets a flat spot(in automotive applications) and eventually knocks. This isn't always true but most of the time. When you have enough force to push through aluminum like that, its enough to either bend rods or damage the bearing. I have a really cool keychain from a Galant VR4(4G63) I built years ago that had a failed brand new OEM tensioner. Considering powersports are roller bearing...hard to say. Glad it's not me lol.
I myself own 2 of these monsters and absolutely love them so I would recommend go ahead and rebuild it as far as stock or big bore really that choice I would think would come from if your going to keep or flip in my area they go between 4 to 6 depending on condition
The big end has definitely got very hot looking at the colour of the crankshaft, they probably ran it without oil till it started to knock, put oil in it, and then the valve broke shortly after. You should really strip the bottom end, too, as there will be a chunk of piston in there somewhere. Mustie1 had a similar failure on a smaller Honda ATV, but his was the oil filter fitted the wrong way round. Hope you get it sorted.
I agree with your thought. I also came to that conclusion based on how much dirt was around the motor, and the oil color (although hard to judge based on the coolant contamination) was very black, and dirty, especially when he pulled off the oil filter cover. I’m sure that poor machine never saw an oil change or even had the level checked. Glad to see he’s rebuilding it, the machine is totally worth it. Super rare, unique, and that motor is based off the ultra reliable and powerful XR650R dirt bike.
I noticed the head nut next to the bad valve was really hard to release. I'm thinking, since this seems to be a common problem, I would inspect the water jacket in that area. I have seen manufacture errors like this in the past. Incomplete water passage heats up that part of the head.also check the valve breaks for porosity in the metal., I don't know how deep you want to dive but you could see if other failures are in the same production year. Could have been a bad "lot" of valves, or heads. Well it seems the law of odds caught up with ya. You have had a few easy ones lately.. 👍
Back when I was still turning wrenches we had something we referred to as "floating a valve". You could find a bent or broken valve especially in small V8's like the 318 that had been over revved for to long, running wide open for extended periods. Timing chain, cam, rockers and everything in the top end would check out fine, other than a bent or broken valve or two. I wonder if that exhaust mod allowed this 700 to sustain higher RPMs than it could safely handle, it floated a valve and ate itself? I call it floating a valve because at higher RPMs it can be possible if the valve springs are to weak to keep up for the valve to hang open for that split second it takes to get smacked by the piston. I'll admit I didn't catch on until the second time it happened in my personal sleeper build that I went with heavier valve springs, after I did that no more issues with floating valves. Now at the end of this video I see this may be a common issue with this engine so that tells me the springs are to weak from the factory. I didn't see heavier valve springs on your list of parts, (or if they even make them), but you mentioned the big bore kit hopefully it comes with them. I know this video is a year old but maybe you'll see this and it helps. Take care and God Bless... EDIT FOR PS. I had to add you need to tear this entire engine down and inspect it with the piston having a whole in it who knows what ended up in the bottom end. I know that will add to you total hours into this machine but I'm pretty sure it will save you money in the long run. From watching your videos I also know you want to maintain a good reputation so making sure the entire engine is in good shape will give you piece of mind.
Ive never needed to add oil to mine but i known mine since the dealer first had it and besides changing fluids and filters I have only changed from thumb throttle to twist throttle. I like bikes without after market parts on them better in my opinion they have more protective measure then trying to get more speed or power in my mind. Wish he would been more honest and dropped price to 900 for you
if you do end up going big bore, you will need to remap, so if you go that route, then you know it will be done correctly. I would weigh the cost of big vs standard bore and then check your fuel map. I think this thing was ran wide open lean for too long and damaged the valve which stated the chain reaction of doom.
You forgot about 4 new tires.....there goes your "break even" tally..... Bummer dude, it might end up being a keep and enjoy type thing. Ill bet it is a RIPPER though. Keep up the great work brother. I really do enjoy watching you work on these. Take care, ~Jonny5🥁
Love your stuff man, good shit. Your videos are like ASMR to me lol I put them on and just let them play for hours in the living room. I’m sure my girlfriend and 3yr old daughter are sick of hearing your voice at this point. 🤙🏻😂
I remember back in 2008 when the economy tanked, my local dealer had one of these in the murdered out black spec for like $3999.99...the thing was like half price. My dad almost got it he loved the independent rear suspension.
Brocken valve and dropped into the sylinder causing it to not turn completely over would definitely be my guess!! Definitely a top end problem!! And yes I had a buddy of mine that blew up a 385 stroker motor that I had built and I was out of town working!! I told him to get it back to the shop!!! The first thing I did when I got off the interstate and home I went straight for the drain plug!!! Well there was definitely over a gallon of straight antifreeze come out first thing and then I new it was junk!!!
1. Initially: My gut says it threw a rod and needs both top and bottom rebuild $1000, Tires $500, Plastics and MSC $500, Labor $1500-$2000. Hope I'm wrong. 2. I did think valves when the guy described the noise. Also felt seller was withholding info. 3. I did think to look at the plug before buy. Probably could have got this for $1000 or
Where do you find these fixer uppers? I would love to find a few of these to work on. I really enjoy looking at your approach to fixing these machines.
I’ve owned one of these with a programmer, pipe, intake, air box lid delete and it came to life for sure. However, these really need a PC5 tuner and custom dyno/tune to assure no lean conditions. I was screaming at the screen when you were inspecting it…”noooo, the motor is shot!” 😂
My 400EX did the exact same thing but I was doing 65mph when it failed! I had a drag bike shop in Anchorage fix it with boring it. Port and polish and a few other things. After that it was the best race wheeler I ever owned!
Damn man. I worked on one of these that suddenly quit running one day. It had fuel, spark and air, but still wouldn’t run. I tore the engine down and found a small machine screw that was keeping one intake valve open a good bit. Just wedged in between the valve and the seat, never made contact with the piston. I removed it, and the thing ran perfect 😂
When you have a stuck nut or bolt or anything with threads, try tightening it just a little bit then rotate to remove. I know it sounds counter intuitive, but it works most of the time because you're trying to break it free and that tiny bit of movement is usually all it takes. It's a possibility that someone revved the engine way past redline and valve float, piston collision *pop* now you have part of a valve bouncing around in there...or improper fuel.
You would think the ride in the back of the truck would have stirred up the oil and coolant. I bet the put that crank bolt cover on with an impact. Those things don’t have to be very tight. Can’t wait to see the inside!
The fuel tuner caused the top end to blow up. I’ve have one of those and a bunch of the foreman models. All the ones I put fuel tuner on blew the top end. If I left them stock they’d run forever even if it was burning oil
Ok, Head is fairly easy fix, Might need a shave and a seat check for cracks, check all valves for straight or replace ALL valves Cylinder sleeve=re-sleeve that sucker to stock and buy a new piston and rings unless you are brave and weld piston up. If you are going to race the thing then yes your parts list is the way to go. You do Great work young man.
The good thing is you have the knowledge to repair it .The block isn't damaged and he said he wasn't going that fast when it stopped running. So I don't think your looking at major damage. Wish you the best git er done.
"It just stopped working" Translation "We heard a big noise and then a crap ton of clanking around until it finally seized up."
Man I have quickly become addicted to your channel, this is rad ass content and the vlog style going to buy then fixing is making them all hits. Congrats 👏
Love your channel I’m a new subscriber, if I could make 1 suggestion I would bring some tools when you go look at these bikes on the get go and pull the plugs and bore scope them yourself:)
Watching this shows something important that I need to work on for myself: treating each task as a voyage of discovery instead of a major catastrophe. Total zen. No stress. Well done.
Im 42 and been watching your videos for past month... I cant stop. I am working on my sons atv and I can relate a bit. Your content is so good... I made my 12 year old son watch it with me and now his addicted too. Thank you for not cursing in your videos, even when you hit the bottom end. I would not be able to keep my cool like you do considering the problems you face here and there.
That dude lied to your face and on camera.. I'm 58, from a different generation. This would be a good time to call a man out.
Pretty sure he did just not as loud a you suggest
I've said it before I'll say it again. I love how calm and methodical you are. I wish I could be mire like this when I get into projects especially when unexpected problems arise. Looking forward to the 300 being finished as well. As for this I'd go big bore. You have more proof of work than almost any reseller. You should be able to get a premium for this when it's all said and done. Keep up the great work.
I be throwing stuff all over
I like his calm too but I want to throw stuff when he repeats himself 5 different time. Roll forward back stuck on something. Starter stuck on something. Manual roll stater 3 times stuck on something. Choose top or bottom end to open up. Pull spark plug where is it hung up.
If I had to guess. It was a chain reaction of events. First started by the lexx pipe and cdi box upgrade. More exhaust flow due to enlarged pipe and adjusted fuel map due to cdi upgrade Which in turn allowed to rev higher and floated a valve. In turn piston meets valve and boom bob's your uncle. The hole in the piston is from the valve stem giving it a little pokey pokey. Imo. I'd go back to stock. This particular machine is very robust right from factory. After market parts destroy machines at least in my experiences. For general all purpose riding, stock is the way to go. Just my opinion.
very good answer and i think the right one
My uncle’s names is Patrick
Agree. Keep it Honda reliable
Do you think there's some of that piston in the bottom end still it would suck to go through all that trouble and have a piece of the piston get sucked up in the bottom end I think it should get a whole tear down and inspection
This answer is correct!
Great stuff sir! I’m not even into ATVs, but I enjoy learning stuff and understanding how everything works. You’re highly skilled. Thanks!
He does everything bike quads side-by-side and snow mobiles etc
No he can't figure out valve float
He can't even figure out how it over revved
And bent the valve breaking it off he's looking and saying stupid things like it didn't get enough oil.. every bent valve in history is from over-revving 94% of the time
I have the same bike. The seller did the same thing to me…..said he was riding it and it just stopped. Told me it was the solenoid stopping it from turning over. Paid “$1,700”for it…..must be the scammers price for exploded 700’s. Hope you put out more tutorials so I know how to repair this thing. Up until your video no one has put anything online about the Honda 700xx.
Get a boreascope and take it with you on your inspections. It's a great tool that will save you thousands and help the seller to remember what really happened to it. 🙂 It will also give you way more leverage on the amount you are willing to pay. You might have been able to get it for $900 - $1000. If they won't allow you to scope it just walk away you'll be doing yourself a favor. You will know they are hiding something!!!! Great teardown and assement back at your shop.
Borescope* lmao
@Tripp Holland really bro? Lmao
Tear the whole engine down to inspect and clean everything with this money involved.
@@billhartsfield424 I was just going to say. Plus, if you have a hole in the piston, who knows what little bits of metal went through it and are wedged somewhere, just waiting to be dislodged by the vibrations of a running engine.
No no no. The seller already said someone had scoped it and the piston looked OK. This was most likely storage damage......
My guess is valve failure, too. I’d stick with stock bore and all Honda parts, rebuild it and flip it. Great video!
You forgot to add in battery. And tires this is a big loss dang atleast were getting good content
Don’t forget to look in the bottom end for that little chunk that came from the hole in the piston. That could cause problems after a rebuild. Keep up the good work.
Since the valve broke, the bottom end is damaged. The connecting rod bearing for sure should get replaced. If I did this I would rebuild entire engine, probably all bearings and seals plus anything worn.
The camshaft with a flat spot is beginning to fail, it should be replaced.
My experience working on all different types of engines is that when there is broken metal in the engine, inside the oil it ends up in the bearings, gear teeth, anywhere oil goes. Those items likely should be replaced.
Usually this guy's repairs are sound, his thoughts bottom end is ok are way off. The piston had a hole in it ... where did the metal go? The crank stopped turning ... the force or piston coming to abrupt stop .... what parts saw those extreme loads? Were they designed to take it?
Sorry to see all the damage. I would remove that aftermarket tuning box. Seen them break before and leaned out the engine. Good luck with the rebuild.
This answer is correct.
Helt enig :)
så det er flerer vikinger her :P@@VikingNorway-pb5tm829
Awesome video man. Good luck with the rebuild. I'm not familiar with trx700 but I've seen that kinda damage from downshifting instead of upshifting. Engine spins to fast, valve springs can't keep up and piston makes contact with the valves. At least it's in good hands now.
That’s my guess.
Dude if you're someone who knows what you're doing as you do, this is 100% worth the rebuild on one of these. Especially if you're getting any deals on parts.
When you're getting a good deal you have to assume the worst and not take seller info at face value. That usually works in your favor except for when it doesn't. When it doesn't, we get some great content and a real world idea of the risks associated with "needs work".
I’m wondering if that tuner box removed the rev limit and it was over reved and then boom!!
Or it leaned out
with my experience over the years i can say over rev with loose lash adjustment
You wouder to.mutch stop.over analizeing
But he said he was going only 15 mph. Ha ha
@@JeffTucker-j1p than he said it was idling
Honda out did there selves on the Trx 700, this thing is wild. The rear end alone is bad ass!
this seems to be the best small engine repair channel on the tube, thanks!
He knew that it had catastrophic failure he just wanted to unload it and hope that he could get somebody to buy it and take it without too many questions he's not an idiot even if you're not mechanically inclined you know when something don't look right like a spark plug
I really like the blog style videos 👍🏾 Especially when you bring us along for the ride.
Throw everything at it, big bore stage 3 , hot cams. New power commander. This is where you get your revenge on that dam turbo. Keep this quad Joe, now you have to room to run something that’s gonna be that fast.
I agree
I think this machine would be worth it to do a complete rebuild. They are somewhat rare and would be great to add to a collection. Value in my area is between $7K-$8K. Even if you put several thousand into it, it's worth it.
If you're getting $7k-$8k in your area let me know where you're at. I'll send them to you all day long for $6k, you can make a nice profit and so can I!
Solution, if possible, find a secondhand engine…
@@danebowen729 he's up in Wisconsin I'm not for sure what part
7-8k😂😂😂😂😂
@@kyleeubanks252 what’s funny about that? They go for 7k in my area advertised as ‘needs tune-up’. That’s selling prices, not listing prices.
I think you should do a complete engine rebuild. Why? Because I am doing that same thing on my 700xx and I could use all the help and advice. LOL! I had metal shavings in the bottom section....
My cam bearing(s) failed and caused huge damage. Can't wait for the followup videos on this. Great job!
It failed at high RPM, not doing 15 mph as he stated. the valve head was hammering around the cylinder for several revs before it locked.
That crank has definitely gotten very hot in the past to have turned that blue. Might be worth double checking the crank bearings and rod bearing
It came like that from the factory, They heat treated it.
Yeah you can look up the OEM part and see that its heat treated on the top like that so I don't think the crank overheated, guessing broken woodruff key on the flywheel or something and skipped timing.
They heat the crank up to press the the connecting rod / bearings in
Do a big bore kit for sure!!
That's how it's assembled, heated and pressed
Also check your oil reservoir in the bottom there's two screens in the hoses that go in sometimes when you replace the o-rings in it you bend those screens and you don't get oil flow to your motor you restrict it and they clog up and everybody forgets about them so you might want to check those out too the black oil reservoir canister the screens are built into the hose on the bottom
Glad to see this on your channel. I bought one in March and it's a beast. I bet it ran low on oil. I gotta add oil every few hours on mine. Fun watching you fix just about anything.
you shouldnt have to might wanna get that checked out before it ends up like his or atleast make it easier on yourself i have to fill my ltz 400 because the case it cracked so i know how it feel
I admire your love for the mechanic work you do. Great talent and awesome videos. Keep up the good work.
Bummer, I would have never drove so far to pick up a bike that didn't run. Especially one where the engine was locked up. Too bad, cause it's a good lookin' bike. I didn't even know Honda made one-cylinders that big... Reminds me of the legendary two-stroke 500cc "Quadzilla" that Suzuki used to make. They were simpler, and were a bit easier to work on though. Those were wicked awesome bikes! I wish you the best of success buddy, I know you'll be able to make this one into a runner. Who knows, maybe you'll find some cheap parts and you'll ultimately break even!
I wish you well, and peace out from Quebec,
Cheers!
:P
WOW that is an insane amount of carnage. Usually you see that kind of damage in a multi cylinder engine that keeps running, but a single cylinder engine normally dies before they're damaged that badly. Crazy!!
Maybe it was not locking up at first and they tried to pull/jump start her?
Maybe they dragged that bugger for miles with a truck trying to free it up. They were definitely not being open and honest with him in my opinion.
@@DDLovettExactly, they were deceptive douchbags. Karma
Because this quad is pretty rare and you make money from TH-cam, this is worth rebuilding man. It is a super cool quad for sure
I think I would take the entire engine out of the frame and rebuilt it the best proper way you can. Obviously new bearings, new cylinder, new piston and rings and I would even install a new cam. Costly...yes, but than you will have a near new engine you can rely on for a long time... JMHO Thumbs Up!
Connecting rod stretched? Overheated wicked bad at high r's. Multiple points of failure. My theory. Definitely big bore with stage 3 hot cams. My take. Excellent video thanks for taking us along
Loving your channel!!
Watching your shows everyday lately. I’ve grown up with motorbikes so it’s great to be learning so much about the inner workings!!
Thanks for sharing . Keep doing what your doing 👌Reuben from Queensland Australia
Great video Joe go for a big bore it should elevate the valve issue as common problem on this model investing in a big bore is the route I would go but get feedback of others aswell and see what works best for you have a great week mate look forward to the rebuild video 📹
Vinnie is quality control dog and he's just making sure you're doing it correctly lol
With that hole in the piston I would do what ever it takes to clean out the bottom end. There has to be some stuff got down there. Good job as always
We used to dump kerosene in the case and drain it and repeat. Sloshing it around and dump it our where the head bolts on.
@@mattsloop2736 Kerosene is probably great for carbon build up, sludge, oil, whatever soft thing you wanna erase, but I don't think it will work great on any metal pieces that might have already ended up at the bottom end.
@@BXtremP it used to rinse the shavings out pretty good. But that was when we didn't have money to rebuild the whole engine lol. Cheap redneck ways.
@@mattsloop2736 Well sometimes the old ways are still the best. Sometimes the car/motorcycle isn't worth spending too much money on it until you're sure it can be saved. Look at the cool channel NoNonsenseKnewsHow, the dude often use diesel to clean or unseaze old rusty cylinder in rusted old cars he's trying to start up after decades.
People upgrade pipes and compression and all kinds of things on four-wheelers and every other kind of moter I just think they were ripping on it riding the wheels off of it and not maintaining it and maintenancing it the way you're supposed to and checking it out when you hear noises and making sure everything's okay that's why it failed you can't ride the wheels off of it and not maintenance it I know this video is old but great video and God bless
piston hitting valve.. is usually a good idea to replace rod / bottom end too...
With the force of the impact, It has more than likely affected the rod / big end bearing...
So basically your looking at a FULL rebuild... Bottom end, Piston, Barrel, Head etc...
I'd never take my chances and keep that bottom end in there now...
I have decided that the next dirt bike or quad that I buy, I will take Joe with me, because he gets these good deals everyday. I don't know how he does it. Great Video as always Joe.
itsc called watching FB and CL all day everyday THAN being the guy who gets the deal
Build it back to Oem, also loose the "tuning" box, together with bad maintenance (old and not enough oil!) probably the cause of failure!
The seller was FOS anyhow, but you'll fix it like always!
^^This. If you're racing and already plan to rebuild the engine on a regular schedule, fine, go wild with the upgrades. But the vast majority of owners should just keep the thing stock.
Say you do a "big 3" upgrade and you gain 10% peak horsepower...the reality is you're pushing that engine much closer to its limit. Honda's engineers knew exactly what they were doing when they designed that engine, and they deliberately built in that 10% as design margin. Anything you do to reclaim that extra power comes at the cost of reliability.
If it were me, I would be splitting those cases and looking for any metal chunks. Clearly there is atleast one decent sized one in there somewhere cause of the hole in the piston. The crank rod looked like it had too much side to side movement as others have said so I would do a closer inspection of that. At a minimum given the money your going to put into it with a new head, cylinder, piston, rings, cam and chain, I would think you would atleast want to spend the little extra money for bottom end gaskets to ensure there are no metal chunks floating around down there. It would also allow you to do an inspection of the transmission while you have it split. It would really suck to put all that money into it just to discover something else was messed up that you could have taken care of cheap.
I believe it had to do with the mapping system he put on it with the pipe. It most likely increased fuel/air mixture beyond the specs. Just my thoughts.
everyone holds the throttle open , and lets the motor run against the rev limiter , that may have caused the problem , or if that part of the cdi box was bad , just a thought. Great content👍
If the guy bore scoped the cylinder there is no way he didn't see all that damage and with a valve sitting on top the piston.
I have an 08'. I was thinking about messaging you to see if you were interested, but I live in Illinois mid state. These quads are beasts! The independent rear end definitely makes a difference in getting over stuff and uneven terrain. You fix it you're probably gonna wanna keep it!
This statement is true.
Nah raptor 700 is king it’s not close
Judging from cam and broken valve. My guess would be over tightened valves causing valve to kiss piston and wear out cam. Can't wait to see this one run. I didn't know they made a 700cc. Nice find. 👍
Also if the motor was taken apart maybe the wrong gaskets were used. Honda likes to use shims as gaskets to shim cam journals and head spacing.
I'd say your absolutely correct! I've owned a 700xx many years an the valves need to be adjusted or they get to tight
Got a 3 year old Polaris 1000 xp v twin in right now, dropped valve in cylinder 2, guy kept riding. To limp it back to his trailer by then it was toast. Gonna be about a $2500 rebuild if I find everything it it needs. Even roasted fuel injection. Polaris wouldn't touch it, would slap in new engine that's it. Would be around $5500 for that. Keep up the good work. Love the dog, mine don't like the shop she just chills out front all day. Unless it's freezing.
I hope you plan to finish this up and take us for the ride. I hate watching this and then have no resolution.
Love the content.
Ouch, that sucks. Hindsight, it looks like if you pulled the spark plug, you would have noticed it was mechanically re-gapped
Edit: Clearly I posted this before getting to the end of the video, sorry lol
Could someone have taken it way past red line to float a valve or two so when the piston came up it hit a valve which broke causing all the damage? I like the way you do your diagnostics,you’re easy to follow!
That's my initial guess.
Thank you that's exactly what happened
HIs diagnostic skills are a lot to be desired, it drives me nuts😂 and I've done this for many years I don't know how many times I can watch him except for the screw-ups. And comedy.
That rod bearing has to much side to side play in it. Better double ck that. Great video as always. Keep them coming
I agree with you.
Far too much side to side for my liking also 🤷♂️ 💯 should of checked the plug instantly!
Not too much
I agree
this answer is correct. And with the after market mods grenadeing this machine, it was also run extremely hard, beat up from the street up. It's one thing riding fast, but they were raw dogging it, that's why they were modding it, so they can beat it harder.
This is fun to watch. We are learning a lot. Backyard mech stuff.
It’s so good for you to know your way around these machines and for you to be able to give it a look over and then go with your instincts on what you believe is wrong with it. It’s too bad that you can’t trust anyone when it comes to people selling stuff because when it comes to money, you can’t trust a god damn thing that comes out of a person’s mouth. People will just beat on their stuff and break it,then they’ll have the nerve to tell you that it only needs the carb cleaned or something like that. Once you get into tearing down the engine, you come across something that’s one step away from catastrophic failure!
Awesome video. I always enjoy the work you do on quads. This particular one...well, it sucks how bad it is. As for me, if I'm keeping it, I go big bore kit no doubt. It sounds like you're wanting to sell it after its fixed so knowing these machines are beasts in stock form, why pay the extra money into an already expensive project?? Can't wait for part 2 and see it all come together.
Man I really like that quad sorry for all the damage on it, I hope you get it back up and ripping again👍🏼👍🏼
Joe even if had no rod you get it going no time nice buy looking forward for first ride
I'd definitely would install with the big bore kit, somehow I would feel more justified with the rebuild..
I would definitely call the original owner up letting him know what a great guy he is..
Love you videos.
Thanks for raising the value of my 700xx I swear no one knows about these gems.
I just snapped the crank in mine last night so it’s funny this just popped up on my feed.
Please let us know if you find cause I’ll be searching for mine!
You should really invest in your own borescope and bring it along with you while checking over these ATVs. Especially if the listing says the engine is locked up or not rotating. Simple enough to pull the spark plug and see for yourself what happened internally. Even just pulling the spark plug would have been a huge red flag, and from there, you could negotiate the price down even further. Probably wouldn't hurt to do your homework before purchasing on the price of replacement parts, based on what you know from the ad. Even if it didn't need everything listed, once you found the damage you could do some quick calculations and go from there. If the seller isn't willing to let you do at least that, walk away. He definitely knew something internal had let go, why else would he mention that someone else had borescoped it before you came along? As someone else mentioned further down in the comments, I would definitely check the flywheel key during the rebuild. If it sheared, it could have very easily skipped timing.
That’s a really good thing that I’m sure not many people would think about. And super useful in his situation with buying stuff that needs work weather it’s running or not.
Here is what I think happened, the small coolant hose you seen at first that was leaking caused the owner to add coolant from time to time. He neglected to put coolant in on a regular basis and the head cracked causing the coolant to leak into the crank case. Due to that happening, caused the oil to lose it's lubricity and not keep the valves running smooth and lubed, in turn heating up the components in the head, also visible by the discoloration, and eventually dropping the valve causing the carnage you know see.
New Subscriber here! If I had to take a wild guess, there might be a deficiency in the spring tension with the factory valves. They might not have enough spring tension to place on the valve, causing them to float, especially after it's heated up. Maybe there is an aftermarket valve train assembly you can get for it.
Once you take the block out with the 4 valves are you supposed to be able to push the valve open by hand?
@@captaindeadpool1640 You shouldn't be able to with ease. Those springs are supposed to have good tension. Are you working on a motor?
You really know your stuff buddy,I really enjoy watching your videos and I’m also learning a few things,great stuff.Watching from NB Canada
When you bend valves at high RPM the valve can break and when it does this is what you get. Why did it come out of time in order to bend? Tensioner. Plain and simple. You should also get into the bottom end, it rarely ends well when you put a hole in the piston. The bearing gets a flat spot(in automotive applications) and eventually knocks. This isn't always true but most of the time. When you have enough force to push through aluminum like that, its enough to either bend rods or damage the bearing. I have a really cool keychain from a Galant VR4(4G63) I built years ago that had a failed brand new OEM tensioner. Considering powersports are roller bearing...hard to say. Glad it's not me lol.
Ran low on oil caused that failure. Go with the big bore kit!
I myself own 2 of these monsters and absolutely love them so I would recommend go ahead and rebuild it as far as stock or big bore really that choice I would think would come from if your going to keep or flip in my area they go between 4 to 6 depending on condition
The big end has definitely got very hot looking at the colour of the crankshaft, they probably ran it without oil till it started to knock, put oil in it, and then the valve broke shortly after.
You should really strip the bottom end, too, as there will be a chunk of piston in there somewhere.
Mustie1 had a similar failure on a smaller Honda ATV, but his was the oil filter fitted the wrong way round.
Hope you get it sorted.
New to your channel love watching you brake the bikes / quads down and diagnose issues and fix them.
Hi, over revving did the damage, value bouncing. ?
That's a beast of a bike!
Check out my channel. My XX has been my favorite machine! EHS Big 3 mods, featuring the Barkers Performance exhaust 💥
@@trailsandtribulations7137 I'll definitely check out your channel now. I have cool vids too 😉
Lack of maintenance is probably why it went
I agree with your thought. I also came to that conclusion based on how much dirt was around the motor, and the oil color (although hard to judge based on the coolant contamination) was very black, and dirty, especially when he pulled off the oil filter cover. I’m sure that poor machine never saw an oil change or even had the level checked. Glad to see he’s rebuilding it, the machine is totally worth it. Super rare, unique, and that motor is based off the ultra reliable and powerful XR650R dirt bike.
I noticed the head nut next to the bad valve was really hard to release. I'm thinking, since this seems to be a common problem, I would inspect the water jacket in that area. I have seen manufacture errors like this in the past. Incomplete water passage heats up that part of the head.also check the valve breaks for porosity in the metal., I don't know how deep you want to dive but you could see if other failures are in the same production year. Could have been a bad "lot" of valves, or heads. Well it seems the law of odds caught up with ya. You have had a few easy ones lately.. 👍
Back when I was still turning wrenches we had something we referred to as "floating a valve". You could find a bent or broken valve especially in small V8's like the 318 that had been over revved for to long, running wide open for extended periods. Timing chain, cam, rockers and everything in the top end would check out fine, other than a bent or broken valve or two. I wonder if that exhaust mod allowed this 700 to sustain higher RPMs than it could safely handle, it floated a valve and ate itself? I call it floating a valve because at higher RPMs it can be possible if the valve springs are to weak to keep up for the valve to hang open for that split second it takes to get smacked by the piston. I'll admit I didn't catch on until the second time it happened in my personal sleeper build that I went with heavier valve springs, after I did that no more issues with floating valves.
Now at the end of this video I see this may be a common issue with this engine so that tells me the springs are to weak from the factory.
I didn't see heavier valve springs on your list of parts, (or if they even make them), but you mentioned the big bore kit hopefully it comes with them.
I know this video is a year old but maybe you'll see this and it helps.
Take care and God Bless...
EDIT FOR PS.
I had to add you need to tear this entire engine down and inspect it with the piston having a whole in it who knows what ended up in the bottom end.
I know that will add to you total hours into this machine but I'm pretty sure it will save you money in the long run.
From watching your videos I also know you want to maintain a good reputation so making sure the entire engine is in good shape will give you piece of mind.
You've just got such a good attitude. Good on ya , Joe!
Hell yea man keep the good content coming
Ive never needed to add oil to mine but i known mine since the dealer first had it and besides changing fluids and filters I have only changed from thumb throttle to twist throttle. I like bikes without after market parts on them better in my opinion they have more protective measure then trying to get more speed or power in my mind. Wish he would been more honest and dropped price to 900 for you
if you do end up going big bore, you will need to remap, so if you go that route, then you know it will be done correctly. I would weigh the cost of big vs standard bore and then check your fuel map. I think this thing was ran wide open lean for too long and damaged the valve which stated the chain reaction of doom.
You forgot about 4 new tires.....there goes your "break even" tally.....
Bummer dude, it might end up being a keep and enjoy type thing.
Ill bet it is a RIPPER though.
Keep up the great work brother.
I really do enjoy watching you work on these.
Take care,
~Jonny5🥁
Love your stuff man, good shit. Your videos are like ASMR to me lol I put them on and just let them play for hours in the living room. I’m sure my girlfriend and 3yr old daughter are sick of hearing your voice at this point. 🤙🏻😂
Big bore love mine
Did you not fix this I don’t see the part 2 aha had me watching the whole thing 😂🤘
Sounds like a portable borescope would be a good tool to have with you when negotiating price!
“ Honda doesn’t like making anything big horsepower.”
Crf450 just breathing fire in the corner.
I remember back in 2008 when the economy tanked, my local dealer had one of these in the murdered out black spec for like $3999.99...the thing was like half price. My dad almost got it he loved the independent rear suspension.
Brocken valve and dropped into the sylinder causing it to not turn completely over would definitely be my guess!! Definitely a top end problem!! And yes I had a buddy of mine that blew up a 385 stroker motor that I had built and I was out of town working!! I told him to get it back to the shop!!! The first thing I did when I got off the interstate and home I went straight for the drain plug!!! Well there was definitely over a gallon of straight antifreeze come out first thing and then I new it was junk!!!
1. Initially: My gut says it threw a rod and needs both top and bottom rebuild $1000, Tires $500, Plastics and MSC $500, Labor $1500-$2000. Hope I'm wrong.
2. I did think valves when the guy described the noise. Also felt seller was withholding info.
3. I did think to look at the plug before buy. Probably could have got this for $1000 or
Where do you find these fixer uppers? I would love to find a few of these to work on. I really enjoy looking at your approach to fixing these machines.
I’ve owned one of these with a programmer, pipe, intake, air box lid delete and it came to life for sure. However, these really need a PC5 tuner and custom dyno/tune to assure no lean conditions. I was screaming at the screen when you were inspecting it…”noooo, the motor is shot!” 😂
Also, I have a video posted on timing for mine
My 400EX did the exact same thing but I was doing 65mph when it failed! I had a drag bike shop in Anchorage fix it with boring it. Port and polish and a few other things. After that it was the best race wheeler I ever owned!
Is there shops here in anchorage that works on older motorcycles my buddies r6 is throwing codes
R8's still my favorite 😍
Really surprised you don't have a pickup. Being a homeowner, I feel it's just about mandatory
Damn man. I worked on one of these that suddenly quit running one day. It had fuel, spark and air, but still wouldn’t run. I tore the engine down and found a small machine screw that was keeping one intake valve open a good bit. Just wedged in between the valve and the seat, never made contact with the piston. I removed it, and the thing ran perfect 😂
Thanks, this is the type of content i want, makes me want to start working on stuff my self.
I just need a bigger garage
When you have a stuck nut or bolt or anything with threads, try tightening it just a little bit then rotate to remove. I know it sounds counter intuitive, but it works most of the time because you're trying to break it free and that tiny bit of movement is usually all it takes.
It's a possibility that someone revved the engine way past redline and valve float, piston collision *pop* now you have part of a valve bouncing around in there...or improper fuel.
You would think the ride in the back of the truck would have stirred up the oil and coolant. I bet the put that crank bolt cover on with an impact. Those things don’t have to be very tight. Can’t wait to see the inside!
The fuel tuner caused the top end to blow up. I’ve have one of those and a bunch of the foreman models. All the ones I put fuel tuner on blew the top end. If I left them stock they’d run forever even if it was burning oil
You’re so honest. I feel badly that you believe the prices claimed to have been paid for these broken ATVs.
You're into it this far I hope you're going to split the cases and at least check out the bottom in for debris
Ok, Head is fairly easy fix, Might need a shave and a seat check for cracks, check all valves for straight or replace ALL valves Cylinder sleeve=re-sleeve that sucker to stock and buy a new piston and rings unless you are brave and weld piston up. If you are going to race the thing then yes your parts list is the way to go. You do Great work young man.
The good thing is you have the knowledge to repair it .The block isn't damaged and he said he wasn't going that fast when it stopped running. So I don't think your looking at major damage. Wish you the best git er done.