chain tensioner

[hocman123]

i just finished rebuilding my top end after i have taken it all part to find my chain tensioner was bad. fixed it all up got it running good just to bring it out for a weekend trip to have it brakedown on the end of 2nd day after bring it back home i pulled the tensioner and just as i thoought broken again.

what could cause this to brake like this?

this is my 2nd one in a month to go through so something has to be casuing it maybe something in my lower end but i am not sure

[togup]

alright you say you have a fresh rebuilt TOP end that mean you did not change your timing chain? The chain could be to loose whipping the tensioner. Second ,were the chain guides put back in ?

[CJM]

I helped him do it and yes the chain was tight and we replaced the guide that you can simply pull out.

[aDviSol2y]

Might just be bad luck.

[hocman123]

well the big resaon i ask is b/c i remember someone saying that there's broke b/c somthing else whent bad in the bottom end and i was hopping to get a idea of what to look for before i take the case off

[TRX_450]

well from what youve posted it sounds like you DIDNT change the timing chain, and thats more than likely the problem.

[togup]

Originally posted by CJM
I helped him do it and yes the chain was tight and we replaced the guide that you can simply pull out.
can you better describe the damage to the tensioner? I have had the same one forever so I dont have a clue

[hocman123]

the internal spring on the tensioner keeps brakeing and idk what to do

[coastie720]

are you installing it fully extended? Or are you retracting it correctly, installing it, then releasing the spring?

[hocman123]

yes i am installing it the right way i keep the plastic hold in install everything else then put it in and pull the plastic out and then chain gets all tight

[TRXRacer1]

Originally posted by TRX_450
well from what youve posted it sounds like you DIDNT change the timing chain, and thats more than likely the problem. Although I don't always believe a chain replacement is necessary I'd have to agree here. What happens is if your tensioner is almost fully extended in order to keep that chain tight then they will fail faster. That's something you wouldn't automatically know either unless you were measuring for it. The CRF chain is cheap compared to the tensioner, might want to add it to your next order.

[hocman123]

Originally posted by TRXRacer1
Although I don't always believe a chain replacement is necessary I'd have to agree here. What happens is if your tensioner is almost fully extended in order to keep that chain tight then they will fail faster. That's something you wouldn't automatically know either unless you were measuring for it. The CRF chain is cheap compared to the tensioner, might want to add it to your next order.

yea i also belive u don't have to do it everytime but maybe it is my time to replace it really sucks but is better then blowing 70 dollers on tensioners every 10 hours of ride

and crf is that a honda atv b/c i allways hear about the chain but never seen a quad called crf on the part sites

[TRXRacer1]

You are correct. Crf as in 02-08 crf450r dirt bike. The trx450r is too long. Service honda has the chain for 33.96 and the 400ex tensioner for 54.44. Don't forget a right side case gasket.

[hocman123]

thanks for the help i wont forget the gaskit but with the axel bearings i need to do this is going to be one expensive order

[Pt's400ex]

Just to let you know depending on where the tensioner is actually broke it can be repaired. There's a snap ring I think that holds the end together. Take that off and you can rewined the metal spring inside. It took me a couple of hours before I finely figured it out but it saved me $50 anyways it's worth a shot. Jim

[CJM]

Originally posted by Pt's400ex
Just to let you know depending on where the tensioner is actually broke it can be repaired. There's a snap ring I think that holds the end together. Take that off and you can rewined the metal spring inside. It took me a couple of hours before I finely figured it out but it saved me $50 anyways it's worth a shot. Jim

Good to know :)