Jump to content
TJA

99 foreman engine rebuild.

Recommended Posts

Good morning, well the engine locked up on my Foreman. So I am looking for parts. I noticed a brand on eBay called Niche. Anybody use any of their parts? Anyone have any brand they recommend? Thanks in advance!

Share this post


Link to post
Share on other sites
 

I might use a Niche brake cable or something along those lines.  No way I'd use anything they make in an engine.

 

What all are you planning on doing? 

 

Having your stock cylinder bored to a new oversized piston is the way to go on the top end.  If you don't have a local shop that can do it send it to G&H.  Use a Shindy piston once you determine how much OS you need to go.

 

If your rod is shot (likely if it seized) then send your crank to Vince at Mr Crankshaft.com.  He will install a new Vesrah (made in Japan) rod on it and true and send it back to you for a fraction of what a new OEM crank will cost you.

 

New timing chain (OEM or DID)

 

New seals on shifter, crank (rear alt cover), front and rear output shaft. 

 

New valve stem seals.

 

 

  • Like 3

Share this post


Link to post
Share on other sites
 

I'm not sure what broke, it was sitting at idle warming up to go get my deer and it made a loud crack and stopped immediately. The previous owner had replaced the top end with ebay stuff ( probably chinese) so the stock jug is long gone. It always had valve noise, I'm just hoping not to put a mint into this thing. I only have about $1500 in it and the rest is in reasonable shape. I really won't know until I tear it down. Thanks for the reply and the references. 

Share this post


Link to post
Share on other sites
 

Is it a 400 or 450?  The 450 cylinders bolt onto the 400, and you keep the 400 head for a little bump in compression.

 

Looks like a new cylinder is $300, then you'd have to get a piston, rings, wrist pin etc.

 

Used will run you $100 or so on ebay, and then you could get a Shindy piston for $75ish.  If you have a local shop a bore shouldn't cost you much.

 

Or you could see if the ebay seller will ship the cylinder directly to G&H, then have them do the work and send on to you.

 

https://www.ghdiscountatvsupply.com/honda-trx450-foreman-engine-motor-top-rebuild-kit-and-cylinder-machining-service/

 

 

  • Like 1

Share this post


Link to post
Share on other sites
 

G+H Discount ATV does a great job and their price is right ---- but , I think you said the jug has been changed before to likely China stuff , I wouldn't want a China jug or pay to have a China jug bored , I would ask G+H if they have a OEM jug they could sell you and bore that one , or buy a used OEM jug from PowerSportsNation and have that one bored  

  • Like 1

Share this post


Link to post
Share on other sites
 

Well, like my Chevy's, I want this to be and upgrade also. How many more CC's can I get with an overbore? I like the idea of more compression, I only run E90 anyways. Better cams? I'm looking for bulletproof power, not racing power. More cubes is always good. More squish, even better. The darn thing never ran right since I got it. The kid who did the "rebuild" was an accountant. I hope he is a better accountant than he is a mechanic. That is why he used the cheapest stuff he could find on eBay. I probably won't get to tear it down until after Christmas but I want to get a plan in process. Thanks again for the ideas. 

Share this post


Link to post
Share on other sites
 

My 450's jug  has been over-sleeved and runs  a  custom 500 piston , then it runs a 400 head on top for more compression , HMF muffler, Dyna-Jet jets 

  • Like 3

Share this post


Link to post
Share on other sites
 

Sounds like timing chain jumped.....Id pull the head and see whats up before ordering too many parts.

 

  • Like 3

Share this post


Link to post
Share on other sites
 

Check out Carolina Cycle, I too came across a 98 450es with a lot of new parts (externally) at a good price. but the motor was extremely loud! (internally). ran strong, not smoking. undergoing a slow tear down, I discovered a bad cam chain tensioner, bad chain. So, to replace the tensioner & chain, (the top end has to come off). bike had only 2535 miles on it, why did it fail? suspect an oil pump failure. (Good luck finding one in the USA) I found two - one in TN, one in CA. or rebuild what you have. Long story short, why not go back to all stock OEM parts. Carolina Cycle was the cheapest OEM parts I could find (Partszilla was overpriced) in my opinion. So, I put a new cylinder, rings, piston & wrist pin in. All stock OEM parts! Bike runs Great, Starts on command. 450 is probably more power than I need, But why not! LOL     Good luck on your rebuild. 

  • Like 1

Share this post


Link to post
Share on other sites
 
 

Running like a top! Start's on command. 

Edited by JRB
Add

Share this post


Link to post
Share on other sites
 
 

Cam tensioner failed. So to replace, the whole topend has to come off. So new oil pump (good luck finding one) cam tensioner,chain,guides, ristpin,piston,rings,cylinder. Did a leak test on valves.  All good. New carb (didn't need). All OEM parts. Carolina cycle was the cheapest. + a New complete wire harness. P.O. had hacked most of it. 

Edited by JRB
Add
  • Like 1

Share this post


Link to post
Share on other sites
 

JRB, mine was running loud also. No smoke. I haven't had the time to tear it down yet. I'm happy to hear that your build came out well.

Share this post


Link to post
Share on other sites
 

All my work was done with the engine in. I would pull the tank then you can remove the top end. See why yours locked up. If you need to remove the F cover, get a cherry picker to lift the front up.

20210814_160240.jpg

  • Like 1

Share this post


Link to post
Share on other sites
 
 

I haven't done anything yet except to push it into the free stall! My wife is going to staples or somewhere to print out the service manual in a high quality and spiral bound format. Right now it is still flintlock season in Pa and I have 1 more tag to fill. Once I read the service manual a couple times, I'll yank the engine and see what I have to work with. Something inside let go as she is seized.

  • Like 1

Share this post


Link to post
Share on other sites
 
 
 
 
 

Yep, carbon build up on the top of the piston, wait a minute... 

Share this post


Link to post
Share on other sites
 
 
 

It has a quarter inch of play in the connecting rod. Is this worth saving? Is the crank case separate from the transmission? All that Chinese aluminum went somewhere. Thanks guys.

Share this post


Link to post
Share on other sites
 

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

×
×
  • Create New...