Plastic cam tensioner gear

I'm putting this out there for consideration and comment.
I've always adjusted manual cam chain adjusters on a running engine and the reason I do this is because as the camshafts rotate, the cams engage and disengage the cam followers and when they do, the cams will load up and unload the cam chain. If you were to adjust the chain on a stopped engine, it's possible to have the engine stopped just as a cam lobe is engaging a cam follower and at that point it would feel like the chain is tight when in fact the chain has been artificially held tight by the force of the cam follower on the cam. Adjusting on the fly, you can "feel" the average tenson. The whole purpose of the tensioner system is to take up the slack and not apply any tension. I really don't like calling the system a tensioning system. It should better be referred to a cam chain adjuster. Mind you, the factory original did apply a light tension due to the fact that the spring applied the "tension" to advance the adjuster.

That's it I'm done. Comments?

I NEVER adjust on a running engine, I always bring the engine up to TDC on 1/6, engine cold, then reset the tensioner.

I wonder : is the upward expansion of a hot engine block and head exceeded by the expansion of the cam chain as it, too, gets hot?

biltonjim wrote: I wonder : is the upward expansion of a hot engine block and head exceeded by the expansion of the cam chain as it, too, gets hot?

It's a great question. There are a lot of variables to be considered. The crankcase, cylinder block and cylinder head are made of aluminum and the co-effecient of linear expansion is greater for aluminum than it is for steel (the camdrive chain) I wonder if anyone has adjusted the chain cold and then checked it hot to see if there's any reason to possibly set the chain tension when the engine is at operating temp rather than when cold.

What ever happens with expansion inside the engine, the stock tensioner would always take up slack in the chain. So it would "adjust" either hot or cold, which ever situation caused the most slack in the chain.

With a water cooled engine, I would think overall expansion in the engine is pretty minimal, but I would bet the chain would "out grow" the rest of engine at operating temperature. Adjusting a manual tensioner when cold would provide some cushion to avoid running too much tension.

My kz650 has a manual adjustment, and it always seems to make more noise when it's warm leading me to think that is loosens up as the engine heats up.

Old topic... But I just ordered the Liskas gear. My wallet is feeling the pain. Wonder if I should have just stolen the wife's cutting board and machined one out of that.