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Weak Cam Chain?

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I've ben reading alot about alot of KLX owners replacing the timing cam chain

saying the stock one is weak. Is this true ? or is it just part of the ACR being out of sync. and needing to be re-set. I plan on the ACR mod. by Brewster

and checking the idler gear and putting bushing and shim in to tighten up it's

loose tolerance. While i'm doing this should the Cam chain be re-placed.?

How many KLX owners have not done any of these changes and your bikes have had no problems.

I have been riding off-road for a long time and know my models fairly well for the past 10-15 years and always thought the KLX

was a pretty bug free unit, The more I read the more I get concerned, calm my fears about owning a potential time bomb. Thanks Borsy

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Borsy, I've been amazed at the reliability and overall build quality of the KLX. Between my son and myself we've put more than 7,000 hard trail miles on our KLX's without the tiniest breakdown. They've never left us out on the trail. Anything that was broken was due to rider error. :) Any bike you look at, and I repeat - ANY bike will have certain vulnerabilities. Even the XR's after you get to know their quirks. Will the cam chain on your bike let loose? Will the one on mine? I don't know. What I DO know is that they stretch over time and a stretched chain is much more likely to break than a new one. Remember, these engines are designed by the engineers to be "stock". How many of us leave our engines stock? I think the cam chain is vulnerable - especially if you do a big bore, agressive cams, etc. I've seen the damage that a broken cam chain can cause, and that was enough for me to replace mine when I had the top end apart getting a valve job. The shop that did mine charged me next to nothing to put it on cause the engine was all torn down. It was a no brainer. Also, in my opinion, a lot of the "sewing machine" noise in the top end of a tired KLX is a stretched cam chain. As an added benefit, the engine "sounds" much better after doing the chain. The only "issues" that I can think of on the KLX are cam chain weekness, idler gear mis-design, shift star shaping and the ACR. The ACR is an easy fix and in fact has been fixed by the factory on all the newer KLX's. The Idler has been addressed also, but I'd still have a look at it. The shift star is a very easy fix that some people just live with for years without fixing. And the cam chain. You just need to keep an eye on it. I say if you've got the engine torn down - do it. If you don't, wait til you do and replace it then. Hope this helps. I wouldn't worry about the KLX being a time bomb. It IS da bomb! :)

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borsy

The ACR mod will have NO affect on the cam chain. Like Bill said, the chain stretches with use. I replaced mine at around 3500 miles. An easy way to see if your cam chain is stretching is to see how well the marks on the cam sprockets line up with the top of the head, like when you do the valve clearance check.

I can only remember of one KLXer saying that his cam chain broke.

Ride on

Brewster

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Thanks Guys for the replies ! I feel alot better now about owning a KLX, I've never heard much about any real problems with these bikes until buying one and starting to read some user group forums, which would be true for any bike, I come from riding some great bikes, a 1985 XR350, a 1987 TT350, a 1990 WR250 and a 2000 DRZ400 some real great bikes with lots of care free miles. I'm sure with regular TLC the KLX300 will be in my list of Favorites.

Thanks Again, Borsy.

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:):) Give your new ride a chance! You'll end up lovin' her just like the others. :p

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The cam chain on any of the four strokes needs to be replaced for wear periodically. Its a small metal link chain with lots of connectors to wear out over time even though its contained in oil. The crankshaft primary gear suffers more from a worn cam chain than the camshaft sprockets. The bottom end in a KLX may be good up to 10 or 12k without a split-the-case rebuild (for trail riding) if you maintain it. The cam chain and idler gear are the two weak points.

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