Cam Chain Tensioner....beating a dead horse

cyclon36 · Post by **cyclon36** » Tue Dec 07, 2010 9:27 am

Ok, I know this topic has been covered extensively as I just spent the last hour reading the old threads that have to do with it :-)

The tensioner is obviously a problem on these older bikes. Both the parts engines I've torn down have pretty much destroyed tensioner wheels in them and I'm not looking forward to what the one in my CB77 looks like. I've read Ed's sanding procedure but wanted to see if there were any ideas for a lasting solution.

I have a few questions....

1. would it be possible to replace the tensioner wheel with a small sprocket?
2. would machining a new wheel out of teflon or delrin be a good answer?
3. are there any aftermarket replacements that could be retrofitted?

I've also read mention of something about a Kawasaki Z1 replacement but wasn't able to find details on it although I did find this page: http://www.partsnmore.com/parts/kawasak ... ng]=custom

Seems as this site makes sprockets as roller replacements: http://kzzone.com/sprockets.html

If you have any input on these questions, please post up. Thanks

jensen · Post by **jensen** » Tue Dec 07, 2010 9:53 am

Hi,

I use POM, it works.
also for the primary tensioner.

jensen

Snakeoil · Post by **Snakeoil** » Tue Dec 07, 2010 10:17 am

Jensen,

I Googled POM as well as racked my brain for what this must be. It that the Dutch abbreviation for HDP or High Density Polyethylene? What is POM?

I read those threads as well and I remember LM or somebody else saying he made replacements from nylon. I think Teflon is too soft and won't hold up. Delrin would probably work. I also remember somebody saying that the tensioner wheel from a K1 Kawi was the right part, but it is smaller. You may have missed some of the posts on the subject.

regards,
Rob

cyclon36 · Post by **cyclon36** » Tue Dec 07, 2010 10:24 am

Snakeoil wrote:Jensen,

I Googled POM as well as racked my brain for what this must be. It that the Dutch abbreviation for HDP or High Density Polyethylene? What is POM?

I read those threads as well and I remember LM or somebody else saying he made replacements from nylon. I think Teflon is too soft and won't hold up. Delrin would probably work. I also remember somebody saying that the tensioner wheel from a K1 Kawi was the right part, but it is smaller. You may have missed some of the posts on the subject.

regards,
Rob

Had to search for it myself: http://en.wikipedia.org/wiki/Polyoxymethylene_plastic

It is indeed, Delrin.

jensen · Post by **jensen** » Tue Dec 07, 2010 10:50 am

Hi,

this answers your question and your assumption :

http://www2.dupont.com/Plastics/en_US/P ... elrin.html

Jensen

Snakeoil · Post by **Snakeoil** » Tue Dec 07, 2010 1:27 pm

Thanks guys. Looking in McMaster-Carr, they offer several products including Delrin. What I noticed about Delrin is the max operating temp is 200F. That seams a little low for an air cooled engine, but maybe not. There is a similar material called Turcite that is perfect for bearing applications. Only drawback is a 2 inch diameter rod is $86/foot.

regards,
Rob

56_oval · Post by **56_oval** » Fri Dec 10, 2010 3:11 am

Is the cam chain constantly running in oil? I was curious about not running a roller at all, and switching to a runner. It's used on all the newer cars. A long curved plastic foot the the chain rides on. I don't see how it's not possible. Just gotta find a tensioner that fits. But in order for it to fit, the chain has to ride in oil...