Type A can chain tensioner has cracked rubber dampener. Help

[Metal]

Hi guys.
I'm moving along on a full rebuild of my 1970 xs1. I went to tighten the cam chain using the tensioner and I noticed a lot more travel then I was used to seeing. So I backed off the tensioner and removed the whole assembly. My cam chain tensioner is a type A. The rubber cushion dampener block between the tensioner and the push rod had cracked from old age. I need a new cushion. Where can I find a replacement? I think I could carve a new one out of some urithane if I had to. Just don't have any idea what derometer the original rubber is or where to get urethane.

 

[Metal]

The part number is 256- 12232-01-00

 

[TwoManyXS1Bs]

Yellowdog had a similar problem on his '72: http://www.xs650.com/forum/showthread.php?t=29326

I also have type A tensioners. Although it's referenced as a 'rubber' damping block, I believe that it's actually a harder period-typical phenolytic. I'd be interested as well if any of the modern plastics could be used as suitable replacements.

 

[Metal]

So in the end I gave up looking and decided to make my own dampener from tooling plastic. I just drilled out the rivets. The rivets are much bigger than the look. 7.2mm. I recommend starting with a small drill bit then stepping up. I then took the old dampener and traced it's profile and sanded out my new dampener to a snug fit. Now I have to find a way to rivet the unit back together. I'm off to the hardware store to find a solution that's low profile. I'll let you know what I find.

 

[TwoManyXS1Bs]

Thanx, Metal! I've dog-eared this thread...

 

[Metal]

I went to ace hardware and found some 5/16 threaded alloy spacers that were very close to the length needed to hold the unit together. Then for clearance I just used some low profile Allan screws 10-32 1/4 long. I drilled the old rivet holes out to 5/16 and sanded down the new spacers length so they were just a tad short. Use some thread lock and put the hole thing back together. Once installed it worked perfectly. Hope this helps others. Dan.

 

[yellowdog]

Much better solution than mine,I basically added some liquid rubber to mine .!
Reminds me I must take it out and have a look to see if has survived