After a recent rebuild, all was well for about 100 miles and now I have a intermittent clicking/snapping noise, more noticeable after warm up. Sounds very, very similar to the clicking that the auto decomp does when kick starting. No noticable power loss or any unusal performance change above idle. No hiccups, etc when it does click at idle. Clicking is very intermittent and no discernable pattern of when it clicks. Any thoughts / ideas? Cam chain? tensioner? Is it the autodecomp? If it is the autodecomp - what exactly is it doing ? Is it the kick start auto decomp cycle or is it kick-back cycle? I've reviewed and digested the drawing of the autodecomp mechanism and I think I understand how both operate but maybe I'm missing something. Come on guys, I'm pullin my hair out!!!
I've seen this before and it's most likely one of two things. If you have the de-comp cable adjusted without enough slack the rocker will hit the de-compressor arm on the head. You'll know if this is the case because the little arm on the head will be twitching every time the valve opens. This will make a rythmic clicking that keeps time with the RPM. If you have a clicking that comes and goes for no apparent reason regardless of RPM than it's your cam chain guides. You can get the rear guide out by removeing the cylinder head cover and the cam. You'll have to remove the right side engine cover to get at the bolt that holds it on. To replace the front guide you have to pull the head. The good news is the clicking will probably go away from replaceing just the rear guide. Also, the dimensions for cam chain tensioner tool in the honda manual are wrong. What I did was grind an old flat blade screwdriver so it could wind up the tensioner.
This is my XR650R making the click/snapping noise, posted on rrussell's computer last evening to save time....the clicking noise is not constant and usually only heard at idle after warm up. We're not absolutely certain it's the de-comp systems because the bike never misses or stutters when the clicking occurs. maybe it's not trying to de-comp and your are correct in the adjuster wearing. It's definitly not the manual lever decomp as it never "pulses" and has plenty of slack.Swapping the adjuster is a simple process and I should've done it when apart. Have any idea what the snapping/clicking sound is when the tensioner is worn. What would actually cause the sound? Curious. Thanks
It's the damnest thing, when you take the guides out and inspect them you'll see that they are worn but nothing about thier apearance would make you think that they are worn out. However, at the end of thier service life the rear one no longer applys enough tension so the chain will find a frequency it likes (usually at lower rpm) and it will oscilate. At first the clicking will come and go but eventually it becomes constant. Your cam chain is living dog years right now so get at least the rear one changed. Before you tare it apart double check your valve clearances to make sure it's not the issue. I don't think it is but the rule is check the easy stuff first.
Thanks a lot XRider, that helped me a lot Too tight manual decomp,constant clicking from L EX valve. It is/was best heard from bouncing off of front fender when turning front wheel to the right, while sitting on bike trying to figure where is it coming from Thanks a lot! Lesson learned
I do! I'm so glad, and happy it doesn't need to be spend $$ on it too It was so exciting to putting tank and all back up knowing it is for last time
I miss routed my decomp cable once and yeh, if I turned the bars hard left the engine died. Had me scared for a minute out in the middle of no where.
