Cam Chain Tension

[Ivan]

Couple of ideas here:

If the chain is adjusted correctly, you may be hearing lifter noise, which is very similar, especially on a cold engine.

Also, in regard to cam chain wear, the guides in the engine wear as well. They are plastic and get grooves in them. They are plenty thick and I don't think will ever wear to the point the chain rubs metal to metal. On my bike, the chain was loose, even though the replacement engine I bought had a new chain in it. Peering through the chain galley, I saw the guides were worn as well. It is also possible the head had been milled down a bit much as well. My remedy was to chuck the tensioner housing in a lathe, and stick a live center in the bore that accepts the rod. I was able to remove about 200 thousandths of material from the mounting surface. This allows the rod to protrude farther into the engine, giving more adjustment range. I just needed some shorter bolts, and it has worked very well for over 2000 miles.

Just an idea or two.

[firecrackerboom]

it doesn't happen when it is cold, usually i just hear the noise for a bit when i come to a stop, and then when i accelerate past 2 or 2.5 k rpms, it goes away. When I come to a stop again, usually the noise is gone.

[Ivan]

I bet that is lifter noise. Before the bike gets fully warmed up, they have a bit too much lash. You don't hear it at higher revs, since they are quicker and the other engine noises drown them out. By the next stop, the engine has warmed up enough to close down the valve lash to where it doesn't clatter so much.

Anyone agree or disagree?

[desert1]

Cam chain life

I read somewhere that a cam chain should last for 100,000 kms or was that miles? Anyway Fire's bike only has 26,000 miles on it.....perhaps just valve noise.....
Bruce
78XS1100

[chrisso]

On this same subject- why did Yamaha not have automatic Cam Chain adjusters when they designed it?Ive had other 4 cylinder Jappers of around the same era & they didnt need the C Chain adjusted.Just a thought.........

[Korr]

there is about a 50% reduction in noise when i have the bike in gear. I just noticed it tonight after i moved my bike to a parking space outside my carport without my helmet. i was power walking it over and it sounded awfully quiet. would our bikes make less engine noise in gear compared to idle? it amazed me to hear the bike sound so trouble free.

just read your post Tad...thnx for the reassurance that they will make noise period. very relieved

oh shoot read some more lol

on the subject of automatic cam chain adjusters, i saw some videos of people replacing them for manual adjusters on their suzuki drz bikes. maybe they know something we don't. saw the vids on youtube.

[strippedFJ]

Originally posted by Korr
there is about a 50% reduction in noise when i have the bike in gear. I just noticed it tonight after i moved my bike to a parking space outside my carport without my helmet. i was power walking it over and it sounded awfully quiet. would our bikes make less engine noise in gear compared to idle? it amazed me to hear the bike sound so trouble free.

just read your post Tad...thnx for the reassurance that they will make noise period. very relieved

oh shoot read some more lol

on the subject of automatic cam chain adjusters, i saw some videos of people replacing them for manual adjusters on their suzuki drz bikes. maybe they know something we don't. saw the vids on youtube.

Auto cam chain tensioners proved to be very flaky on 70's/80's Jap 4's and all worked motors required replacement with a manual unit (or conversion of the auto to manual). The auto tensioners could slip under heavy loads.

[prometheus578]

"Valve lash noise"

Anyone agree or disagree?

Ok, I'll play your game.
One of the nice things about bucket/shim systems.. is that they're quiet.
As the engine/valves wear, the valves seat themselve up further into the head... reducing valve clearance. So... it's not like your bike will get louder, if anything, it'll get quieter.
Now, bikes with overhead cams and actual tappets.. they can get noisey if they're adjusted too loose. I've seen(and done) that before.
But, that being said... even when I was running with a bent valve and my clearance there was about .035", the engine was deceptively quiet.
The only noise you should hear from these bikes is cam chain noise... and then, you really shouldn't be hearing that, either.

Ok, and seeing how I'm playing games...
That tensioner/ chain guide issue.
Guides come with a groove already in them. Not so much a groove, but a ridge along the middle. This acts as a guide for the chain links, so the chain doesn't flop from side to side as it tracks along it.
Now, I haven't seen YOUR guide, but if it's got grooves in it, they'd be the first I have ever seen. The ends of the guide may look a little worn, but grooves?
Having to grind down the tensioner housing in order to take up slack... Hhmmm...
Somethings not right. I don't think a chain guide could be that grooved, that it would allow a "new" chain to have enough slack in it that a modification like that would be needed.
Chains stretch, this we know. And when they stretch, the tensioner must be adjusted, to push further against the guide to remove the slack.
Of course, we also know... that it's the distance between the links that is lengthened, producing that slack, as the chain wears.
this increased link distance will also be throwing your valve timing off.(an increased distance between the crank and the intake cam gear, as well as the two cams being slightly out of synch with each other, due to the sloppiness in the chain.)
Again, I haven't seen your chain, nor it's guide, so...
Maybe I'm wrong.
(Oh, that hurt!)

[Ivan]

The guides are worn enough that the ridge is on the outside of the guide. On another engine I have, the middle ridge is worn to nothing near the lower ends of the guides. Another thing I noticed is that all the marks on either of my tensioner rods were near the outer most 3/4 inch of adjustment, indicating that the tensioner was never used close to full compression. I am guessing that the head on my engine got milled down some too, leading to extra slack in the chain. The PO said the engine was completely rebuilt and machined, so I'd bet this may be the case on my engine. I checked the chain, and it has liittle if any wear. According to the PO, it was new. Anyhoot, machining the mounting face of the tensioner allowed the spring to be more compressed, making the chain a tad more snug. I haven't bought a degree wheel yet to properly check cam timing. If they are retarded, and it runs like it does now, I will probably soil my armor if I get them back to original timing!

As far as valve lash, shim buckets are definitely quieter than tappets. Since the original poster indicated he has not had the bike long, I didn't know if his PO had messed up the lash, that is why I went with that.

At times there is a method to my madness, at times.

[TADracer]

Ivan,

The giudes should not be worn that much. The rollers on the chain ride the ridge in the middle of the guide so if that stuff is right then then the chain will actually not rub on the guide too much since the rollers will act as wheels. So if you have that kind of wear then something is not right.

If your head is milled then you should be able to see evidence by the little bosses on the exhaust side where the exhaust studs screw in. Removing even a couple of thousandths from the head surface will cut into these a bit. I am not sure if you can see that with the head on the motor, though.

[prometheus578]

Thanks for the update, Ivan.
You obviously know what you're talking about.
I wrote what I did just for general knowlege.
You seem to have an extreme case.

[Ivan]

Originally posted by prometheus578
You seem to have an extreme case.

Everything is like that with me. I can't even wake up, comb my hair and take a leak without having to call rotorooter.