cam chain tensioner
 

Hi
I'm just about to give my bike a complete service. I'm confident about everything, however the cam chain is a mystery to me. Do I need to do anything with it, or adjust the tensioner?
Thanks David

Hey David,
If you can't hear the cam chain rattling then things are probably okay and there's no huge need to worry about it unless you are leaving for a long trip.
But if you are like me (paranoid) you might want to take the cam chain tensioner off and see how many of the grooves on the tension rod are engaged. Doing so will tell you how much more slack the tensioner can take up.
According to an earlier thread the spring in the tensioner isn't strong enough to engage the last 5 grooves so if there are 5 (or less) grooves above the base of the tensioner body then the chain is pretty well stretched out and you should think about replacing it.
If your bike is really high mileage or old you might want to think about replacing the tensioner spring too,like any spring it gets weaker with age and a weak spring would mean an ineffective tensioner (never heard of one failing though). Again, if it's not doing it's job you will hear it.Good luck and sorry if this sounds a bit convoluted.
Nate

Thanks Nate
I too am paranoid.
I'll give this a try.
Dave

STOP!
Before removing the entire tensioner, you want to check the wear of the chain, as follows:
1: remove the big (size 19, I think, nut that holds the spring in place
2: remove the tensioner by removing the two Allen bolts
Then count the number of notches that are visible from the plunger. If the number is below two thirds of the total number of notches your chain is OK.
If you don't remove the spring first the plunger will go out by spring force when removing the tensioner f.ck.ng up the reading.

Auke

Yes,
Sorry! You have to take the spring out first or it will push the tensioner rod all the way out once there isn't a cam chain to stop it. The latch that holds the tensioner rod in place is one-way, so in addition to giving you a false idea about a worn chain, if you put it back in while it was completely extended it could make your cam chain way too tight.
Sorry I didn't make this clear in my earlier posting,
Nate

Thanks for the advice.
I don't hear any rattle just yet so its probably best to leave it. At least now I know how to do it, should I get bored, or more paranoid.
Cheers Dave