verslagen1 wrote on 12/31/69 at 16:00:08:

I didn't necessarily "dig" through the other posts...heck, I had to resurrect the topic from page 3 anyway.  So, I merely scanned them.  Yet, this subject isn't really where I was going with this.

But while we're theorizing, have you figured out exactly what causes the problem with the tensioner?  That is what I'm pursuing...obviously, the chain and gear have been eliminated.

...to which I see that you state that "we are dealing with a complex system of steel and plastic"

Come on...it ain't too complex for a nit pickin' engineer, is it?

Anyway, I'm wondering about the guides.  Mine has wear but the SSM has no measurement checks in it.

I just wondered if anyone bought a new one and applied either scale or a micrometer to it, yet.

If not, I guess I'll just have to buy a new one, because I'm not closing this engine up until I know what caused the tensioner extension.

verslagen1 wrote on 12/31/69 at 16:00:08:


Not discounting your tensioner modification, as I recall you calculated the chain slack somewhere.  I guess that with 64 links and .015" stretch found in 21 pins there is roughly .100" gain in length overall.  Didn't you calculate a ratio of the tensioner extension somewhere?

Therefore, since we can pretty much eliminate wear on the hardened cam gears from the "everything" list, it is really just a matter of chain and tensioner/guides.

Dam, even if you just have to open the case and utilize the 2nd hole in your mod, it's still gonna cost you $15 for a new case gasket.

I can't wait to see what Stinger's chain looks like after 30K, tomorrow.  Has anyone, with a tensioner that separated, measured their cam chain?  Does it even reach the service limit?

When I took mine apart, the plunger was extended 22mm.  I measured the chain and calculated that I should get 50k miles out of the chain itself given the amount of stretch at the time.

If the cover comes off without tearing, you can reuse the gasket.  It's been recommended that a gasket sealer be applied around the oil channel.  I've done it twice so far.  All I can say is if it leaks, replace it.

Yeah, of2 right, the 2 holer not the only way to extend the life.  You can bend the tensioner guide to take up some of the slack.  The issue I have with that is that dam plastic.

I wish there was an engine to play with.

Here's my idea (sorry, I don't have a spare engine to play with):

1) remove the ratchet paw from the tensionizer. This would stop the over tensioning when eng gets hot by allowing pull back.
2) mount a coil spring on guide, at a spot approx 1/2 way up (at about the 7" mark on the steel rule in your picture Greg). This is to reduce slap at rev'ing.  To do this, a gap would need to be measured to figure out size of spring. The spring has to be mounted (two small bolts (4-40?) threaded in the guide and a small plate?).  Would need a engineer type to do some calc's here.  Need to calc the spring strength and length so not to interfere with regular action of tensioner and still prevent slap.  Must also figure  in for some wear.

Note: this experiment would be reversible with only two small holes left in the guide.

Other choice ( not easily reversible) would be to machine the jug to add an externally adjustable sping in the middle of the guide.  I know Honda's have a setup that might be adapted.  Would require loosing some fins on the section where the chain is and getting the parts from another type bike.

verslagen1 wrote on 12/31/69 at 16:00:08:


If the "slack side" becomes more slack, the tensioner is (theoretically) supposed to ratchet out as needed.  That will gradually pull any additional bend out of the guide because it won't be able to spring back.  As you say, most of the wear is at the bottom radius and that tells me that in operation the chain guide is pretty straight anyway.

Pardon me....but let me correct.  Maybe I was simplifying too much, but The Book states 21 Pins or 20 "Pitch".  If you have 2 pins per link you have 10 links.  Please count.



If you are counting the connecting plates separately, then I guess that I'll have to say that my rear chain conversion required a 210 links of 520 chain

My plan is to bend the right side (straight) guide that is not moved by the adjuster and make the bend permanent and durable by backing it up with a block of wood.

The chain will have worn the valve timing 'retarded' by X degrees to make the X slop that I find when I open it up.  

I will then run the timing forward by X degrees by moving that slop to the right side by bending the straight guide up at the top near the cam gear and backing it up with the wooden block.  In essence, I put it back to a near factory stock valve timing and I renew the tensioner travel all at the same time.  

10,000 to 15,000 miles of free tensioner travel.

Add that to the Slavy/Verslagen 30,000-50,000 mile tricks that you can then do next and maybe I'll get somewhat closer to the engineering wear limit on my chain before I replace it.