Cam bearings and tensioner woes

XsJosh

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Some of you, ok a couple of you were following my cam timing thread. Now that I feel the timing is dialed in I went to reassemble everything and noticed my cam bearings are not feeling very good. Two of them spin smoothly and the other 2 feel like junk. So I ordered 4 new ones koyo 16005. While it's all apart I also found I'm missing the little brass (or rubber coated metal from mikesxs) spacer from my cam chain tensioner. I've been running this way probably 7 or 8 years with no noticable I'll effects (though it explains why my tensioner is so far in). Question is, do I really need to replace this spacer? If you've read this far, thanks for any input.
 
If it's what I'm thinking it is, it's not a spacer but rather a damper washer. Without it, the tensioner can tick like loose valves. Older models had a copper washer fitted, late models switched to that rubber/metal washer. But, that new washer is 1mm thicker than the old copper ones so Yamaha compensated for that by shortening the adjuster screw by 1mm. So, measure the length of your adjuster screw. That will tell you which damper washer you need. Details on the washers and screws are here, post 22 and 23 .....

http://www.xs650.com/threads/cam-chain-tensioners.1056/page-2

If your adjuster is screwed really far in, that has nothing to do with the missing damper washer, it means your cam chain is all stretched out and probably needs to be replaced.
 
I have to respectfully disagree, when I first re-phased my engine the cam chain was new. With the tensioner adjusted per the manual it was very noisy. Figuring the motor was going to have to come apart again anyway, I adjusted the tensioner until the plunger would move in and out 1-2mm while running. The plunger running this way without the damper washer sticks out about the thickness of the new style rubber coated washer. The motor has been quiet this way for probably 3000 miles, though I have to admit it's always concerned me that I might have been running it super tight. (The screw needed to be turned further in to make up for the missing washer) Now the question, which style should I go with? I have what seems to be a later tensioner with out the lock nut. Motor is an 82 or 83.
 
Like I said, measure the length of the adjuster screw. The earlier 60mm long screw uses the 2mm thick copper washer. The later 59mm long screw uses the later 3mm thick rubber/metal washer .....

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Matching the correct washer to the right length screw allows you to make the end of the plunger even with the end of the screw for a correct adjustment ......

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Mismatching the washer and screw length won't .....

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Yes, now that I think about it, you're right. Having no washer will require the adjuster screw be turned in more to compensate.
 
If the motor is an '82 or '83, it should have the type E adjuster assembly which has a lock nut .....

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Maybe with that damper washer missing, someone removed the lock nut because there wasn't room for it since the adjuster screw had to be turned in so far. Examine the plunger. The type E will have a larger head .....

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Definitely an "E" type and the lock nut is there, I was expecting another nut on top of that. Is the washer a friction fit of sorts with the plunger shaft? If not how does it work?
 
No, it's just a loose fit on the shaft. It's there to pad the plunger head when it strikes the back of the adjuster screw. Like I said, if it's missing, you may get a ticking like loose valves.

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The cam chain wears just like any other chain, unevenly. It develops tight and loose spots. Those running against the spring-loaded tensioner are what cause the plunger to "pulse" in and out slightly. And that's what you want to see, a small amount of in-out movement. If it doesn't move at all, you've got it set too tight.
 
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