rebuild issues

[matholland]

I installed new crank bearings, new crank, fresh bore on my cylinder to a 416 with a new je 10;8:1 piston. Stock can for right now. It starts up, I can drive it around...once it gets warm its almost as seething is binding and it wants to kill itself at an idle. I can keep it running by giving it some gas. But if I am barely going in first or low ROMs it is enough that it will kill itself. The first time it did it I thought it locked up. I am not sure where to look on this one. The motor will shake a bit like you can tell something may be getting in a bind.

[Blodg]

Are you sure it is not a jetting issue if it is only at idle? I am not much help but I sure hope it's not an oil circulation problem as that would be a catastrophe with all the work you did to it.

[matholland]

No I'm not sure to be honest. It ran fine before the rebuild. The only thing that changed was a bigger bore and piston. Same exhaust same cam. Now I did pull my carb off and simmer it in lemon juice to clean it real good. I had an issue with my slide after I got it back together it corroded itself to the carb and would not move the slide up at first. I pulled the top of the carb off and cleaned it and it did OK after that. It will sit and idle when its cold just fine and idles great even when it is warm. Earlier when I started it I let it idle for a while and went down the road and back then let it idle again for a bit. I went to pull off and it caused issues again like it did before. If I rev it a bit then it will take off still but if I let off it dies. Then when I try to start it again it will start and die immediately unless I hold the gas a little bit. Even when I drive it and punch it then it still takes off and seems to run good but doesn't seem like jetting is spot on. I didn't figure k would have to rejet with just a bigger bore. Again from the times I have tried this issue is only happening as it gets warm.

How do I go about seeing if it is an oil pump issue? I am not riding it, I'm scared too. Something just doesn't seem right and I don't want to grenade it.

Just to confirm the the ring with the copper goes first with the writing up then the second ring with the writing up them the small ring, the brass ring then the other small ring correct?

[DragonGunner]

Bore size wouldn't matter that much but compression would...were u running high compression b4 the JE..? What r your jets now? I would raise the needle one notch, this allows a little more gas flow, also if you soak it did any gunk get stuck in the air scew area? Amazing how many people clean a carb but never take out the air mixture screw and spring, this also could and might need a touch of a turn out or in, just a little can be a differance...I had a issue with when I gave it gas just a little it would hoke out....took apart the acclester pump and had alot of white dry crap build up, cleaned and it ran perfect.....to check oil flow just loosen the line going out to the tank, start and see if any oil spits out.

[DragonGunner]

also how positive r u that you got the marks lined up on the counter balancer when you put the cases together?

[matholland]

No I wasn't running a high compression before the je. It was a stock compression ratio that was. 020 over. My needle isn't adjustable. It only has one notch. I noticed that when I was cleaning the slide. I am going to pull apart the carb in a bit and go through it and clean everything by hand rather than letting lemon juice do the work. I'll let you know what size jets I have in it now because I don't remember off the top of my head. Not sure which line you are talking about. Are you talking about one of the 2 lines on the clutch side that bolt to the motor?

Thanks for the help!

[matholland]

also how positive r u that you got the marks lined up on the counter balancer when you put the cases together?

I'm positive on this one because this was the first bike I had tore apart that had one. My yfz450 didn't have one and Nome of my 2 strokes did. I made sure I got instructions for this. There was only one way that the lines would meet up...the big part of the balancer was at the bottom...I printed off some instructions on the bottom end because it had the balancer part in it. It looked like it matched with the picture and my lines met up.

[JOHNDOE83]

It could be a jetting issue, 400ex comes lean from the factory and changing pipes, cams and bore size matter greatly for jet size.

There is stock bore 400exs on this site running 200 size main jets and saw great improvements all throughout the rpm range once they went large on jet sizes.

If you haven't changed any jets that could very well be your issue, if the oil is to full it will also sputter and act up.

To check for oil flow, simply disconnect the oil line that returns oil to the oil cooler and start your motor if it spits out a good flow of oil its fine.

Read all the jetting FAQ at www.jetsrus.com this will help you determine whats doing what and were and if its possibly carb related.

[matholland]

It could be a jetting issue, 400ex comes lean from the factory and changing pipes, cams and bore size matter greatly for jet size.

There is stock bore 400exs on this site running 200 size main jets and saw great improvements all throughout the rpm range once they went large on jet sizes.

If you haven't changed any jets that could very well be your issue, if the oil is to full it will also sputter and act up.

To check for oil flow, simply disconnect the oil line that returns oil to the oil cooler and start your motor if it spits out a good flow of oil its fine.

Read all the jetting FAQ at www.jetsrus.com this will help you determine whats doing what and were and if its possibly carb related.

I have changed the jets in it. I'm getting ready to tear into the carb now and will post back with sizes. I am 500ft above sea level. Stock header supertrapp slip on with airlift off and uni air filter. Will post back with results.

[matholland]

Got the carb apart its nasty inside all kinds of corrosion never using lemon juice again. 150 main 42 pilot. Moving up to a 155 main. Air screw was clean and at 2 turns out. Cleaning the carb and I'll post back.

[Blodg]

I have never heard of using lemon juice before?

[matholland]

Alright, I cleaned the carb and got to mess with it a little more this time....it is definately NOT fuel or spark related. Something is definately getting into a bind, and it seems to only happen when the bike is warm or hot....When I first got it out I went up and down my road 4 or 5 times without problems after I got the carb. cleaned. Riding wheelies on it and everything. However, now that it has gotten warm and I tried to go a further distance, I hear a weird noise and I can't target where it is coming from. But when it does it, it almost sounds like it is locking up. It puts a huge strain on the motor (I was in 4th gear the first time it happened, and it just lost all power, I let off and it died)...I am able to start it back up, if I give it gas...if I do not give it gas it wont ever start, and if I let off the gas then it will not idle at this time because there is a little bit of stress on the motor. I was only about 4 or 5 city blocks from my house at this time when this happened....I was able to start it and it happened 6 more times by the time that I got it back to my house...I notice that every once in a great while when I start it cold, its like the starter clutch keeps spinning after its started....(I had dropped the starter clutch, and all the bearings came out when I was rebuilding this quad) I put it back together, so I am wondering if something with that starter clutch isn't right?) IDK WTF is wrong...its very aggrivating, it's been scorching hot outside and I have been sweating balls trying to figure it out.

[Blodg]

To check for oil flow, simply disconnect the oil line that returns oil to the oil cooler and start your motor if it spits out a good flow of oil its fine.


^This goes without saying but just to be sure - after seeing if oil is flowing out of the disconnected line immediately shut the motor off and hook the lines back up. Not so much for you mat but in case any noobs are reading this.

[matholland]

I have never heard of using lemon juice before?

I had saw it on some other forums, and I had google'd it a while back...It seems to be real common on streetbikes as there are usually 4 carb's.

https://www.google.com/search?q=lemon+juice+carb+cleaning&oq=lemon+juice+carb&aqs=chrome.3.69i57j0l3j69i62l2.4850j0&sourceid=chrome&ie=UTF-8

[matholland]

^This goes without saying but just to be sure - after seeing if oil is flowing out of the disconnected line immediately shut the motor off and hook the lines back up. Not so much for you mat but in case any noobs are reading this.

Oh yeah, I have not checked this yet, because after I saw how dirty the carb was from the lemon juice, I figured that was my issue there...after it ran fine and all. Then it got warm again, I didn't want to remove the bolt holding the line, nor did I want hot oil all over me lol, so it is cooling off now.

I have to say, I am almost scared to pull the head off to look at the cylinder....God, I hope nothing is majorly wrong....if there is, I would be very tempted to part it out. lol

[Blodg]

Could the cylinder bore not be sized right and as the piston heats and expands it is too tight? Did the shop that bored it have the actual piston to measure so they know what size to bore it to? That is the only way to properly do it...

[matholland]

I took it to the local honda shop, and I took them the piston and the rings....but that is the only thing that I could come up with as well. I going to run and grab a mic in a bit and look through the plug hole and see if I can see any grooving.

[matholland]

Could the cylinder bore not be sized right and as the piston heats and expands it is too tight? Did the shop that bored it have the actual piston to measure so they know what size to bore it to? That is the only way to properly do it...


Man you hit it right on. I pulled the top end apart. I'm pissed. I am going to raise 9 kinds at the Honda shop for boring my cylinder. Here is some pics.


They are in this album https://picasaweb.google.com/m/viewer#album/116424294864098183298/5881333082523167089

[Blodg]

I did look at the link but can't see any pics...

Of course you should be able to have the local shop do it but for a peace of mind that is why I sent my cylinder out to a reputable shop that deals with building motors as a core business.

[matholland]

I did look at the link but can't see any pics...

Of course you should be able to have the local shop do it but for a peace of mind that is why I sent my cylinder out to a reputable shop that deals with building motors as a core business.

Oops, sorry. Can you see them by going here?

https://plus.google.com/photos/116424294864098183298/albums/5881333082523167089/5902848201830134530?banner=pwa&pid=5902848201830134530&oid=116424294864098183298
https://plus.google.com/photos/116424294864098183298/albums/5881333082523167089/5902848256400742594?banner=pwa&pid=5902848256400742594&oid=116424294864098183298
https://plus.google.com/photos/116424294864098183298/albums/5881333082523167089/5902848290786295826?banner=pwa&pid=5902848290786295826&oid=116424294864098183298

[Blodg]

Wow that is terrible. It sounds like the bore and piston were not sized right but did you ever check to make sure it was getting oil? I would suppose a lack of oil would maybe cause the piston to look the same?

[matholland]

Wow that is terrible. It sounds like the bore and piston were not sized right but did you ever check to make sure it was getting oil? I would suppose a lack of oil would maybe cause the piston to look the same?


No, I didn't unfortunately, I forgot all about it...I went to the auto shop down the rd that I have a key to, and looked for their mic to look down into the cylinder through the spark plug hole, but I spent about 10 minutes and couldn't find it (shop is a mess). I was already aggravated because I couldn't find it in the mess of a shop, so I just came home and pulled the top end off...I know that the piston rings were very hard to get in the cylinder, it seemed awful tight now that I think back...had to use a small screwdriver and start one side, then use the screwdriver to compress the other side, and work my way down. I have always been able to use my fingers on every top end I have been into.

If I held the crank with some string to keep it from slapping, and pull that return line off and hold the starter button, would that simulate the same thing and pump oil? Didn't know if I could test it that way or not? It SHOULD be getting oil, unless it just crapped out on me, but that isn't to say that it is...never assume lol.

I can tell you that there was plenty of oil in the head when I pulled it, and my valve cover gasket was leaking on one side just a tad due to some stripped bolts that I am going to heli-coil this go around....if I don't decide to part it out rather than messing with it...I am about tired of messing with it...160 for piston and gaskets, $50 for the bore...and I still need a cylinder/piston/gaskets...might as well anyway...for 300 bucks you can buy a je piston and a cylinder bored already...There is $500 into a top end, because I know the honda shop isn't going to cover anything...It is so aggravating knowing that I just threw $210 down the drain for a screw up on their part.

[matholland]

Wow that is terrible. It sounds like the bore and piston were not sized right but did you ever check to make sure it was getting oil? I would suppose a lack of oil would maybe cause the piston to look the same?

Also, just thinking out loud here...If it wasn't getting oil at all, do you think that it would have actually seized up rather than after it cools back down, then I am able to start it right back up?

[Blodg]

Also, just thinking out loud here...If it wasn't getting oil at all, do you think that it would have actually seized up rather than after it cools back down, then I am able to start it right back up?

Yes it does sound more like the bore was not sized properly based on the issue with it only doing it when hot and the fact that you said the cam/head was bathed in oil. If the oil was not circulating the cam would have probably shown a lack of oil also.

[DragonGunner]

OMG!!!!! Ya if you checked oil coming out of line your oil flow was good, plus the motion of the crank will through oil up to your cylinder anyway....I would say it was bored to small, or you ran it before you put oil in it......when i put rings in I never could with my fingers, I cut a piece of aluminum license plate and rap around rings with a hose clamp tighten down slightly, oiled really good and slide into cylinder.....this is a shame, if you had oil in it and rings where right I wold be pretty mad. OR if you didn't have enough oil in it and the ol level gets too low it will shut off, that is the senser located under the foot shifter. If this was the case, an you kept trying to start and run it it would be bad new. I had a oil line come lose once in a race...leaked oil 3/4 of a mile then it quite running, started and died and didn't sound right and wouldn't start again.....looked alot like your piston and cyclnder wall....only you know if oil or enough oil was in there....the dealer who did the work may be thinking the same thing.....good luck.

[CJM]

Did you make sure the rings were properly gapped before you installed everything? Also did you test fit the piston?

It is possible it was fine but on the tighter end of the spectrum, you may have possible overlapped a ring (probably an oil ring). I just redid my 450r and had a similar issue where I kept trying to put the cylinder on but it wouldnt go, stupid oil ring kept overlapping.

Id say its time to mic the piston and cylinder, there should be a slight difference.

[matholland]

OMG!!!!! Ya if you checked oil coming out of line your oil flow was good, plus the motion of the crank will through oil up to your cylinder anyway....I would say it was bored to small, or you ran it before you put oil in it......when i put rings in I never could with my fingers, I cut a piece of aluminum license plate and rap around rings with a hose clamp tighten down slightly, oiled really good and slide into cylinder.....this is a shame, if you had oil in it and rings where right I wold be pretty mad. OR if you didn't have enough oil in it and the ol level gets too low it will shut off, that is the senser located under the foot shifter. If this was the case, an you kept trying to start and run it it would be bad new. I had a oil line come lose once in a race...leaked oil 3/4 of a mile then it quite running, started and died and didn't sound right and wouldn't start again.....looked alot like your piston and cyclnder wall....only you know if oil or enough oil was in there....the dealer who did the work may be thinking the same thing.....good luck.

It definately was not an oil level issue. Quad had plenty of oil in. Even when I put the piston in before this one, I was able to use just my fingers to get the piston in the cylinder. Hopefully they will do something and cover some of it, but I would be shocked if they do.

[matholland]

Did you make sure the rings were properly gapped before you installed everything? Also did you test fit the piston?

It is possible it was fine but on the tighter end of the spectrum, you may have possible overlapped a ring (probably an oil ring). I just redid my 450r and had a similar issue where I kept trying to put the cylinder on but it wouldnt go, stupid oil ring kept overlapping.

Id say its time to mic the piston and cylinder, there should be a slight difference.

I did not. Since I took them the piston and the rings both as they said they needed them, I did not thing twice about double checking anything just because I figured they knew what they were doing. I suppose I assumed, and shouldn't have. I was just assuming that with a fresh bore, things should be perfect. I have actually never had a cylinder bored in the quads/bikes I have taken apart as most that need boring are nickle plated. It seems to be just as cheap to get another cylinder and go with a stock bore. Either that, or the piston was wore enough where the cylinder was still fine and all it needed was a hone and a new piston and rings. So getting this cylinder bored is a first for me. I am no pro at this stuff, but I can follow directions, and I have had quite a few apart. I am plenty capable of things, and have always been mechanical inclined it seems. I know that overlapping the rings could be possible, but they seemed to have went in a-ok, and after I bolted the cylinder down I added some more oil to the top of the piston and I cranked the motor over by hand a few times as I always do when installing a top end. The piston went up and down smoothly with no funky noises or anything. I also checked to make sure that it wasn't grooving the cylinder wall or anything and continued on.

[matholland]

Yes it does sound more like the bore was not sized properly based on the issue with it only doing it when hot and the fact that you said the cam/head was bathed in oil. If the oil was not circulating the cam would have probably shown a lack of oil also.

This really sucks. Any thoughts or suggestions on proving that it was a boring issue rather than another mechanical failure or due to something not getting installed right?

[JOHNDOE83]

This really sucks. Any thoughts or suggestions on proving that it was a boring issue rather than another mechanical failure or due to something not getting installed right?

LOL, bring it back to the machinist, pretend like your a new customer and pretend like its a differ cylinder and piston. Tell them you want it check to make sure its right before you install it, if they call you and say its wrong tell them to fix it and why!!! LOL

If they tell you its fine then you might have to pay a shop cost tho :-/

[matholland]

I talked to the honda shop today and talked to the guy that did the boring. I told him what happened and right off the bat he said did you have the 400ex cylinder bored to the 416 with a JE piston, and I said yeah. He said that he set the piston to cylinder clearance at .002. He said that he was going to put it a little looser, but was hesitant on doing so as he didn't want it to make noise. He told me to bring it back in, and he would get me a new JE piston and rebore it for me. So they are definately making it right, and satisfied with the outcome in it. Looks like I did a lot of ranting for nothing.

[Blodg]

Wow that is awesome they are going to stand by it and buy a new piston! I know the shop manual says .002" but when I took one of my bored and stroked 350X motors to a builder years ago he said he does not go by the specified clearances. I am not a builder and don't quote me on this but I am pretty sure he said he went as high as .005-.006" clearance because the modified motors run hotter than a stock motor and, therefore, expand more.

[matholland]

Wow that is awesome they are going to stand by it and buy a new piston! I know the shop manual says .002" but when I took one of my bored and stroked 350X motors to a builder years ago he said he does not go by the specified clearances. I am not a builder and don't quote me on this but I am pretty sure he said he went as high as .005" clearance because the modified motors run hotter than a stock motor and, therefore, expand more.

He said that he was hesitant on going to .0025-.003 when he was originally doing it. I can't seem to find much info on the cylinder to piston clearance on a 416....What is everyone running on theirs so that I can let them know?

[matholland]

After 3 weeks, I got a new cylinder and a new piston from the honda shop...Said they didn't like how the boring came out again...so I JUST got it together today, well actually got it together last night, but didn't put oil in it and put that gas tank on until today after work. I started it, let it idle for a minute, hopped on it and went up and down my road twice, around my house once, got to the edge of the driveway and it died...Now when I try to start it, it will not start at all...even when giving it gas...if I give it some gas while holding the start button I hear some sort of knocking, as it attempts to start, and I can't pinpoint to where it is actually at. It trys to start, its firing, but doesn't actually start...fml...I am so close to parting this POS out and taking a loss on it...

[Blodg]

Hopefully you checked to make 100% sure you have flow from the oil pump before you ran it with the new cylinder and piston?

[CJM]

Sounds like the timings off.

[JOHNDOE83]

I would say if your still using the 155 main jet youll still be way to lean for a 416, possibly needing bigger then 180.

You might wanna invest in some bigger jets before you try to break it in again.

[matholland]

Alright, so another wristpin failure...grooved the crank a bit...lasted a whole 5 minutes...This time it was at an idle, and therefore did not screw the cylinder up....just managed to grove the crank just a hair, and grove the piston a lot in the wristpin hole...apparantly its not getting oil there I guess...I didn't check it for flow, didn't have a chance to, it didn't last long enough....What does this sound like? How can I test the pump if can't get it running....

I am trying to think about the history of it...when I got it, it was running fine, took it on a few rides, but some top end gaskets were leaking and it was smoking....so I tore it down to put new gaskets in it, and a new piston with the same size bore which was .020 over. I put all that back together and it locked up on me about 2 miles from my house.....grooved the cylinder up bad as well as the piston, and the wristpin siezed and grooved the crank....so then I then bored it to a 416 with a je piston, put in a new crank, main bearings and seals, put it back together, and it acted different...it would lock up when hot, but start up again after it cooled off...the wristpin did not sieze in the crank this time even after starting it multiple times and letting it lock up killing itself, but would start back up....Then it got a new cylinder and piston with a rebore, and it lasted its shortest time and siezed the wristpin to the crank....wtf.

I have just realized that I am MISSING the spring that goes behind the oil filter! I am not sure if this could have been causing my problems?? Thinking back, I changed the oil I believe for the first time before I started it on the FIRST piston that had a wristpin failure. I am not sure if the quad even came with one....It could have been missing from the previous owner...I do not remember a spring in there, however it could have fallen out and I not have realized it....I should have known that right off that bat, as there is always a spring there...I would think that I would have noticed this previously, but apparantly not! I have done some searching, and it seems like this would not cause something like this, but I figured I would post this.

As far as jets go, I don't think thats the issue...I have a big collection of jets, and when I jetted it last time, I went the biggest I could and backed myself down...It only has a slip on, and the air lid off, and @ my elevation ~500ft above sea level, it seems to be jetted fine, it wasn't with the 416 when I did this, but if it was that lean it wouldn't run right when the throttle is smashed...Also, if it was, I don't think it would cause a wristpin failure that fast.

[Blodg]

I don't know if missing the spring would cause this problem for sure but it would comprise the oil flow which does sound like your problem.

[matholland]

I talked with a buddy that works on them a lot and he said the spring forces the filter against the cap to force oil through the filter. Otherwise it isn't forced through. He said that you can run them without them so that shouldn't have been the issue. He mentioned he couldn't recall on the top of his head he didn't think the 400exs were this way but he said on some there is a jet that sprays oil to the wrist pin and it could have gotten clogged from the metal shavings. I just can't think of anything else but the oil pump but I don't want to replace that, buy another piston, and the same thing happen again!