Cam chain information

[byron]

I am just looking to start work on the engine and would like some information about the cam chain and it's tensioner.
What is the amount of stretch that is acceptable on that double chain?
What should the contact face of the tensional look like?
Before I stripped the bike down there appeared to be no noise from that area.
Here are three photos of the chain and tensioner taken in a freezing garage this evening

Thanks in advance Byron

 

[fayeslane]

Can't answer your question but given you're that far in why not replace both anyway. They are not expensive and then you would know that it was all good.

 

[solidstate100]

Can't answer your question but given you're that far in why not replace both anyway. They are not expensive and then you would know that it was all good.

^100% that. It would be a false economy and a whole PITA not to do it while you are there - cheap as chips to do.

 

[byron]

So am I right in thinking that there is no measurement for this. It appears to be the original set as there is no clip link.There is a slight groove on the follower and the sprockets appear to be fine.
My feeling is leave it as £75 for the set and £30 for the puller.

 

[solidstate100]

You didn't say what mileage the bike/engine has done, but notwithstanding that as its an airhead engine and if it IS the original, it has no doubt got a couple of decades of age on it at least, and countless heat cycles, which can lead to deterioration of the slipper, piston seals, slipper tensioner etc, ie things are probably now less than optimum etc.

to be fair the photos you posted give no real indication of its true state, really need to be hands on and closely inspect/tweak/pull etc etc, however at the end of the day it is of course your decision, but I know what I would be doing..........

 

[Rob Farmer]

Your sprockets look worn but if it's quiet I'd leave it alone. If you do decide the swap it you will need new sprockets on the crank and camshaft.

 

[Steptoe]

What is the amount of stretch that is acceptable on that double chain?

Double chain must mean that engine is pre 1979 ? If so I'd replace a double chain while the engine is out on the bench.

There's very little stretch/length between a worn out chain and a new one.

 

[byron]

The engine is off an R 90 S and I think I will replace the chain and tensioner. Thanks chaps