clutch rattle?

[gssuzukixxx]

My '77 GS750 rattles when warmed up and idling. With the bike leaning on the side stand the rattle is loudest. If it is vertical the rattle is less but still there. If I lean to the right it goes away.

I figured this sounds like a clutch rattle. But if I pull the clutch in the rattle is still there. I was expecting it to go away or change

What do you guys think?

Brian

[bonanzadave]

Probably a good idea to pull the cover off just to see if there is pending trouble. If the big hub nut is getting loose (which they do...) thats an easy fix. Grab a gasket and maybe some replacement cover screws then a little studying of the project on Cliffs web site.

[blowerbike]

750 kicker bikes have no side load on the basket because of there straight cut primary gears.
check the large center nut but i doubt your rattle is in that area.
maybe starter clutch rattle.

[verde]

Mine rattled like there were marbles in there. Center nut didn't take much effort to get off, but didn't seem loose. Damper springs had some play, so I did the cut it open, shim, and weld the rivets trick outlined here. No more rattle(not counting the cam shaft float). I'll see if I can find my pics of it. I had to do some more aggressive clamping than he shows to get the plate to behave while trying to get it back together.

Clutch basket still rotates when you pull the clutch in, so I wouldn't expect pulling the clutch in to change the noise much. I however do not recall if there was any difference for me.

[gssuzukixxx]

OK thanks for the comments guys. I am going to take the clutch cover off tomorrow and see what I can find.

[gssuzukixxx]

A follow-up for the people who replied to my post; the big centre nut on the clutch was loose. I have now tightened it and working on puting it back together but do not expect any more rattling.

Brian

[verde]

Good to hear.

If you do decide to go back in to shim or replace the damper springs, I'll elaborate on how that process went for me.

[gssuzukixxx]

Well I guess I spoke too soon; put the whole thing back together started it up...still rattles.

Took it apart again. This time I took the clutch basket completely out. Those springs on the back of the big gear thing were loose so I spread them out using a screwdriver til they were not loose. Put all back together, started it up...still rattles.

One thing I did try was taking the oil filler cap of while it was rattling to see if the sound changed or was louder but there was no change. Now I don't think it's the clutch.

Blowerbike suggested the starter clutch so maybe that is my next check.

I had the stator off recently...could the stator rattle.

I don't think it's the cam shaft end play because the rattling goes away when I lean the bike to the right.

[hampshirehog]

Stator could rattle if you didn't put it back on tight I suppose. I'd suspect the starter clutch - this usually makes a distinctive clack-clack-clack noise.

[blowerbike]

starter clutches "clack" when your trying to start the bike.
but loose bolts on the starter clutch will rattle at low idle and usually go away when the revs are brought up.
it will also rattle when releasing the clutch lever and bogging the engine slightly.

[gssuzukixxx]

Can you give me a hint as how to remove the rotor so I can get at the starter clutch?

Also can I tell if the starter clutch is loose without taking the rotor off? There is some play when I try and move the large gear behind the rotor.

Thanks

[blowerbike]

with the stator cover removed try and turn the large gear.
it should only turn one way.
watch the starter clutch housing and see if it moves any as it should be bolted tight to the alt. rotor.
if it is tight then thats probably not your problem.
if you want to remove the rotor to inspect the starter clutch then remove the large bolt in the center and then get a bolt around the thread size of your swing arm pivot bolt and use it to push the rotor off.
there are threads inside of the rotor that you can see when you remove the center bolt.
maybe use a spacer to keep from bugging the end of the crank snout when pushing the rotor off.

[verde]

I don't think it's the cam shaft end play because the rattling goes away when I lean the bike to the right.

Cam shaft end play sounds a lot different too. When I was trying to figure out my noises, someone on here best described it as a tiny hammer and anvil. Listening carefully it is fairly easy to ID it as coming from the head the clutch rattle as coming from lower down.

Hope the starter things pans out.

[gssuzukixxx]

Well I am not going to say that I have solved the rattling problem but for now it does not rattle. Here is what I did:

Checked the ignition timing with a timing light and found that the timing on 1-4 was slightly different than 2-3. Adjust so they are all exactly lined up with the marks. That reduced the rattling quite a bit.

Then I used my carb tune kit and tweeked the carbs so vacuum is exactly the same on all carbs. They were not that different but not perfect; one bar was about 1/4" lower than the rest. When I did that all rattling had stopped.

Brian

[posplayr]

Well I am not going to say that I have solved the rattling problem but for now it does not rattle. Here is what I did:

Checked the ignition timing with a timing light and found that the timing on 1-4 was slightly different than 2-3. Adjust so they are all exactly lined up with the marks. That reduced the rattling quite a bit.

Then I used my carb tune kit and tweeked the carbs so vacuum is exactly the same on all carbs. They were not that different but not perfect; one bar was about 1/4" lower than the rest. When I did that all rattling had stopped.

Brian

not the first time.