TOPIC:

Maybe the Liskas are usable with the narrow valve cover.

 
Yes! Liska use the early design idler bracket as it fits pretty much all styles of cover.

Thanks Zed, I thought so. It's amazing how time flies when your getting older! Years ago, never thought about newer style parts in an early 900 engine. Plus I was going to machine up some of the flat blocks they sell to replace the rubbers, Was going to play with some (DELRIN) material instead of aluminum? But then again? 350° is not very high temp! For the top of cylinder head.  Delrin acetal resin is a crystalline resin with a melting point of 177°C (350°F) Aluminum it is! I just have a lot of delrin scrap stock, it's so easy to work with. Speaking of Liska, I was going to try and make idler cam chain gears with delrin in the center with new quality needle bearings I can get, one of these months or years. 

I make my own blocks using aluminium and the same for the idler centres.
Don't think i would trust Delrin or anything similar.

  

Wow? Any disadvantage to running aluminum vs rubber? I wonder why they did it from factory?
I have hard time finding all those blocks but I have mini mill and lathe and I can totally make them myself.

Excellent Zed, I do recall seeing your post with these idler gears.
Zed would you care to divulge the thickness specs.? for the 4  top pieces?
Of course I can guess and estimate for them. I have a whole pile of used ones!
Maybe you should ad these items to your for sale carb parts! Light weight, easy to ship international, people can send you cores of chain gears.
I'm sure when built new, the factory rubber helped with any excessive noise and vibrations in the valve train.
Very cool stuff!

The rubber is just to give a bit of cushion and sound dampening to the cam chain system.
The solid alloy doesn't degrade like the rubber so is permanent and doesn't make any noticeable noise difference.
I also use modified Z650 tensioner bracket (MIDDLE in the pic) which has a larger roller than the Z9/1000 ( LEFT)  and readily takes a toothed idler which won't wear like the rubber roller does.
The only original rubber parts i use if the bottom roller and the small front guide.