cam chain rattle--tensioner vs chain?

Hello Everyone,

I have a cold start rattle that's progressively getting worse. The bike is relatively low mileage (8k-ish) but has seen a lot of high rpm dirt riding so has lead a relatively tough life.

Apologies if this has been covered elsewhere but I can't find a discussion of how to diagnose a bad cam chain vs bad tensioner. I'm also reading that bad tensioners cause bad chains. I'm happy to replace both but of course would rather not if only one is bad.

The service manual just says to look for damage/stiffness but does not give a spec for how much stretch is too much.

Is Krieger the only option for a manual tensioner?

thanks,

-morgan

I'd just put the Krieger manual tensioner on it and be done with it.

If the stock tensioner is shot this will fix it or if the chain is stretched it will tighten it so either way your fixing the problem with the new tensioner.

I don't have one but helped put one on a klx with a stretched timing chain and it fixed the noisy chain.

Can't get a hold of Kreiger. Any contact info or any other manufacturers?

They're on ebay.
http://www.ebay.com/itm/Yamaha-WR250R-WR250X-cam-chain-tensioner-/302239409096?hash=item465edf63c8:g:8P0AAOSwpDdVgHE6&vxp=mtr

I've had a Krieger on mine from about 7,000km. Changed the chain at 26k, but i figured most of the damage was done in that first 7k with a crappy tensioner. So I got an extra 19k of abuse before it had to have a new one.

Rattles from cold as per instructions, but at operating temp where it really matters, the cam chain is always under full control. The tensioner can't back off unless the locknut is loose. Nice.