mcqlln 3 Posted January 5, 2021 I have a 2001 Foreman S that is smoking extremely bad. Recently changed piston, rings, valves and valve seals. Ran a compression check with reputable instrument three times, showing 210 each time. During the tear down the cylinder did not show any signs of scarring, scratches, etc. and miked out within tolerances in a Haynes manual. Machine runs great right now. Just smokes like crazy and is using a lot of oil. It has gotten hot one time since the rebuild due to the fan not activating, but not real hot. It is on a toggle switch now so it has cooling all the time. Share this post Link to post Share on other sites
toodeep 1,746 Posted January 5, 2021 That compression is high but an oil soaked piston can do that. I have to ask.. Was the cylinder honed and rings staggered on the piston? 1 Share this post Link to post Share on other sites
Fishfiles 20,140 Posted January 5, 2021 How many hours are you talking about ? --- did it smoke right off the bat and never stop , it just might need to burn out oil in the muffler ------ How was the connecting rod wrist pin journal , if it is a loose fit then the piston can wobble and take out the new piston and rings quick ---- did by any chance this engine get flooded and not cleaned out ----- the oil filter backwards ? 1 Share this post Link to post Share on other sites
_Wilson_™ 6,498 Posted January 5, 2021 abit more history of the machine is needed ^^^^ why was the engine rebuilt, etc. Share this post Link to post Share on other sites
mcqlln 3 Posted January 5, 2021 started smoking all of a sudden. low compression. probably not maintained well at it's previous location. Share this post Link to post Share on other sites
mcqlln 3 Posted January 5, 2021 My son did the work and he is pretty concious about making sure all is right. He is a polaris 1000 play in the mud guy so he is always working on some one's machine is his riding group. With the compression good (210) on the rebuild would the rings still be questionable? It got hot one time due to fan switch not operating so my guesswork leans me toward the valve seals? Share this post Link to post Share on other sites
Fishfiles 20,140 Posted January 5, 2021 If it got real hot , it might have fried the valve stem seal or even the o-ring under the valve seat ----- 1 Share this post Link to post Share on other sites
toodeep 1,746 Posted January 5, 2021 High heat will usually damage a piston before it does enough damage to the valve terrain unless it's a prolonged long heat then usually both. If the machine has ever been sunk and has debris inside the motor that fine grit will never let the rings seat properly. 1 Share this post Link to post Share on other sites
jeepwm69 7,413 Posted January 5, 2021 Yep, has it been sunk? If so, until you tear it all the way down and clean it out, you'll probably never get it to stop smoking. Share this post Link to post Share on other sites
_Wilson_™ 6,498 Posted January 5, 2021 4 hours ago, mcqlln said: started smoking all of a sudden. low compression. probably not maintained well at it's previous location. i take it you just purchased this bike ? perhaps sunk by the previous owner ? yep, sounds to me like it's been sunk, Share this post Link to post Share on other sites
Fishfiles 20,140 Posted January 5, 2021 Reading back and in between the lines , I take it that , you installed a new piston , rings right into your used jug ? -- did you do any cross hatch honing on the walls of the bore ? ---- Share this post Link to post Share on other sites
mcqlln 3 Posted January 5, 2021 It has been sunk previously and never torn all the way down. From the advice I am getting here it sounds like it is time to pull the motor and get it on a table for a complete rebuild. Thanks everyone for the words of wisdom and taking your time to help me. 3 Share this post Link to post Share on other sites
shadetree 5,791 Posted January 5, 2021 1 hour ago, mcqlln said: It has been sunk previously and never torn all the way down. From the advice I am getting here it sounds like it is time to pull the motor and get it on a table for a complete rebuild. Thanks everyone for the words of wisdom and taking your time to help me. yep, you are correct..time for a complete tear down and over haul. BE WARNED !! : the crank is now discontinued !!. i am not sure if the rod can be still purchased ?, but i do know a new crank is not around now !. please source a rod before you go tearing into this engine !!. without a rod ? ( if yours is bad ? ), all this work will be for nothing. we are here to guide ya on any help you need...JUST ASK US !. 1 Share this post Link to post Share on other sites
mcqlln 3 Posted January 6, 2021 That kind of knowledge is invaluable!!! Thanks for letting me know. Share this post Link to post Share on other sites
87Iroc 344 Posted January 6, 2021 Used Mr Crankshaft for mine to rebuild the crank. Enjoyed doing bidness with him. 1 Share this post Link to post Share on other sites
mcqlln 3 Posted January 6, 2021 Got contact info and location for Mr. Crankshaft? Need to get a quote before I decide to tear this thing apart. Thanks Share this post Link to post Share on other sites
87Iroc 344 Posted January 6, 2021 http://www.mrcrankshaft.com/ If I had to guess. Somewhere in the 250 range. He's in western TN or KY somewhere. I think I paid 248 shipped for mine and it cost 22 or something to send it out from INdiana to him. 2 Share this post Link to post Share on other sites
jeepwm69 7,413 Posted January 6, 2021 Yep, send it to VInce. He'll get you fixed up. Share this post Link to post Share on other sites
Fishfiles 20,140 Posted January 6, 2021 I have used Mr Crankshaft two times , I seem to remember it was $225 the first time for a 450 using his store brand rod with the freight charges , second time for my 300 I had him upgrade to a Veshra rod and it was $300 I see a few used 450 cranks on e-bay and a brand new one , but they wanted like $600 for that NOS one As far as used goes , every year and model of the 400 and 450 uses the same crank , PSN is a good source --- Share this post Link to post Share on other sites
jeepwm69 7,413 Posted January 6, 2021 Vesrah rods for my 500's are about $100, and he charges about $125, including return shipping, to install and true the crank. 1 Share this post Link to post Share on other sites
87Iroc 344 Posted January 8, 2021 My crannk from him came with a beefy looking rod on it. I had thought all he installed was 'the good ones'... Share this post Link to post Share on other sites
Fishfiles 20,140 Posted January 8, 2021 6 hours ago, 87Iroc said: My crannk from him came with a beefy looking rod on it. I had thought all he installed was 'the good ones'... No , you have to ask for and pay more for the Vesrah rod -------- there was a time not too long ago , maybe 8 years now , when you could get a Honda OEM rod separate of an entire crank assembly from Honda even though there was no part number on the finche 1 Share this post Link to post Share on other sites
jeepwm69 7,413 Posted January 8, 2021 Vince will let you supply your own rod if you want. Here's one for a 450 for $80 shipped. https://www.ebay.com/itm/Vesrah-VA-1017-Connecting-Rod-for-Honda-TRX400-TRX450/162080260798?epid=209919986&hash=item25bcbc82be:g:PnoAAOSwepZXTelR Share this post Link to post Share on other sites
jeepwm69 7,413 Posted January 8, 2021 Even cheaper. If it doesn't look good, the seller has to take it back. https://www.ebay.com/itm/Vesrah-VA-1017-Connecting-Rod-for-Honda-TRX400-TRX450-Open-Box/184519597197?epid=209919986&hash=item2af6399c8d:g:aZYAAOSwxElfhz7o https://www.ebay.com/itm/Honda-TRX-450S-Foreman-1998-2001-Connecting-Rod-Kit-450/383525234886?epid=24002747278&hash=item594be2a8c6:g:KdoAAOSw7GVfxQyB Share this post Link to post Share on other sites
toodeep 1,746 Posted January 8, 2021 The 450 rod/crank is pretty tough. I would tear it down, inspect and go from there. I bet it will be good to go without any worries. If it isn't there are plenty of options posted. 1 Share this post Link to post Share on other sites
