timing chain scraping noise

[relic-rider]

Ever since I got my 81 1000GL from my buddy it makes some terrible scraping metal on metal sounding noises. It only has 13,000 miles on her. I've been trying to isolate the noise since I got it. I've fixed numerous problems so far but none have rid me of this noise. I fixed a loose clutch basket nut, checked the stator housing, rotor and starter clutch. The starter clutch was in great shape and the rotor was on tight. There was one thrust washer missing on the idler gear, which I replaced. The carbs are synced and functioning well.
I just got done checking the top end and valve clearances. All of the clearances were less than .001 and a few were zero. I corrected these to the proper .03-.08 range. The guides look ok as far as I could see from the top. The chain didn't look worn or have any rub marks. The cover didn't have any drag marks on it. I pulled out the tensioner and it appears to be functioning ok. It came out and went in fine and you could hear it pop out once I released the set screw.
Before I adjusted the valves, it was a constant sound. It made the noise at all speeds and RPM's and did it cold and hot. Having the clutch in or out made no difference. Now after I did the valves, it is actually louder at colder engine temps ,and at higher temps, it lessens to its pre valve adjust noise levels. The thing is that every now and then, it gets to a point of not making any noise at all. No scraping, ticking or knocking. This seems to happen after riding a while and mostly in 5th gear at revs of about 2000- 2500. If I hold it there for a while sometimes the engine will stay quiet as a mouse. As soon as I give her more revs or downshift it goes back to the noise.
Could my tensioner still be bad even though it seemed ok? Or do you think my guides are worn? I've done some searching on here and I see a reference to the cam end float. Could this be the cause? The cams seemed in good shape and didn't move around at all when I had the cover off. I'm at a standstill now and my motor has teased me by being the quite mouse I know it should be for short periods. Whats next? Pull the top end? I've had a stethoscope on the engine and the noise is such that it is all over and I cannot isolate it. I'm sure it is cam chain noise, but how do I stop it?

[ta473]

cam chain

Disconnect the tach cable and try it my gs1100gk had a similer noise until i replaced the tach cable.

[relic-rider]

The tach cable was just replaced by my buddy before I bought the bike. I had the tach gear out and it looked ok. I've got to replace the seal on it, though, as it leaks.

[t3rmin]

How do the cam lobes look?

The tensioner is a fairly simple device and as long as it was still springy and re-installed properly (and it sounds like you did), I don't really see how it could be bad.

[80GS750]

have you tried adjusting the cam chain tensioner? make sure its not hung up...mine was way greasy and messy after it sat for so long....

i would pull it off, make sure its operating properly and put it back on..

my crankcase seems to be the loudest part of my bike, but it also sat for a while so its gonna take a few miles until the whole thing gets lubed the way it should be....

[mark]

With zero valve clearance, you've been placing a pretty good strain on your valve train. Perhaps you might pull the cams and check the ends and bearing journals for wear. Oil passage clogged?

If the sound is as bad as you say, I wouldn't ride the bike much anymore until I figured it out.

[brveagle]

i'd suspect the cam chain tensioner is not doing it's job

[relic-rider]

Yeah, I'll pull that off again and go thru it. I'll put an extra wind on the outer knob spring. Wish you could get that thing off without pulling the carbs. At least my airbox comes off easy.

[gustovh]

PM sent
Vince

[relic-rider]

Got some videos now!

Ok. Today I pulled the tensioner again and cleaned it up. I got the ball moving good, sanded the beveled end of the pushrod and wound the outer spring 1 more round. Still no go. Just as loud as before. I actually figured out how to make a couple of short movies with my camera. These are my first ever effort, so don't laugh. The sound on the camera comes through a little louder than it is, but you can get the jist of how annoying it is. The first movie is the bike at cold startup just idling at 1000 Rpms. The second is the bike with the choke on and running at 2500 Rpms. I turned the choke off toward the end of the second video.

[relic-rider]

Anyone have any ideas as to what is causing my noise??? It is sooooo irritating.

[chef1366]

You for sure have isolated this noise to the cam chain tensioner? Have you checked the clutch? Are the cam chain tensioner rods still good?

[vjgsor750]

Somebody swapped in the rare gs diesel when you werent looking. Holy smokes! When I first got my 82 GS750 I thought the clatter was a serious problem but was just normal. That there is some noise. The plastic (or plastic compound) cam chain guides could be shot. I dont know if you have to split the cases to change. Good luck.

[relic-rider]

Yeah, I'm figuring something is wrong with the guides causing the chain to drag on something. Looks like I'll have to tear down the top end sooner than later. I was going to wait, but this bugs the sheeet out of me. I hate pulling in somewhere and making such a racket. Kind of gives Suzuki a bad name. This kind of loud noise doesn't save lives, it wrecks motors. That way I can address a few small leaks I have also. BTW, nice avatar. Old school AC/DC rocks. My first album was Highway to Hell and that broke me out of a sheltered life in High School.

[gustovh]

I thought that mine was bad, your motor sounds like it is ready to self destruct. If you go after the cam chain guides, you only need to remove the valve cover to replace the front guide, plus the cams. The rear adjuster guide you need to pull the jugs.
V