What's this noise?

[ianralph]

Have a listen to this periodic clicking/rattle from my '79 GS1000S.

https://ls1.sceggs.nsw.edu.au/~ian/GS/gsrattle.mp3

The sound does not appear to come from anywhere in particular and can be "felt" through the hand when using a screwdriver as a stethoscope.

I've posted twice about this noise before thinking the cause was something else - I am still using the original cam chain tensioner, not the APE unit that trippivot recommended (yet):

http://www.thegsresources.com/_forum/showthread.php?t=135224

http://www.thegsresources.com/_forum/showthread.php?t=135085

Suggestions as to the cause, and remedy, of the sound are welcome.

[p_s]

Dry clutch? Hope you figure it out.

[chef1366]

Sounds like valves. Is the recorder near the head?

[Suzuki_Don]

Have a listen to this periodic clicking/rattle from my '79 GS1000S.

https://ls1.sceggs.nsw.edu.au/~ian/GS/gsrattle.mp3

The sound does not appear to come from anywhere in particular and can be "felt" through the hand when using a screwdriver as a stethoscope.

I've posted twice about this noise before thinking the cause was something else - I am still using the original cam chain tensioner, not the APE unit that trippivot recommended (yet):

http://www.thegsresources.com/_forum/showthread.php?t=135224

http://www.thegsresources.com/_forum/showthread.php?t=135085

Suggestions as to the cause, and remedy, of the sound are welcome.

Ian where abouts in Sydney are you? What suburb I mean. Check all your fluids. I'd lift the valve cover and see if it's dry in there for a start.

[ianralph]

Thanks for the suggestions:

The recorder is near the head - there is plenty of oil circulating in the head and I've already worked on the clutch by adding spacers to tension the springs.

It think the recorder (my phone) makes the "normal" sounds sound worse than they are - it does sound a bit dry, but it's got plenty of new oil up in the head.

Don - I'm in Elanora Heights on the northern beaches.

Ian

[Steve]

Is it that intermittant 'clacking' sound you are concerned about?

Does is go away if you increase revs to about 1500?

It sounds like cam end float and is somewhat common. It is my understanding that the only damage caused by this is to your ears. There is a thrust surface that is worn, allowing the cam to float sideways. Increasing revs a bit increases tension on the cam chain, pulling the cam back to the center. There was a solution ( <-- click the link) offered by 49er some time ago. It involves some machine work, so you will have to evaluate for yourself if it will be worth it.

.

[chiphead]

Hard to tell from the recording but before you go to far take the time to do a mint carb synch and see if the noise goes away. Steve is right about the cam end float but a good carb synch may correct the issue.

[mike-s]

A Carb synch? if were talking about that mechanical noise would have thought it was a bit too metallicy sounding for it to be related to that. To me carb tune issues would sound like it interrupts the rythem of the engine more as well. But a synch, hey, crazier things have happened and i am by no means an absolute expert on the subject, i just know enough to be a little dangerous

First thing first, if the carb synch is a bust i would suggest you take the rocker cover off, checking the clearances as well as how much play you have with the in & ex cams r.e. lateral movement as others have suggested.

Another thought, not that its a plesant thing to consider, but i wonder what the possibility is that it could be top end (i.e. valve) damage? The reason im suggesting it is the sound seems pretty significant and overshadows the normal cam & chain sounds quite a lot.

The engine isn't chewing any oil is it? Also have you done a compression test? IF there is some mechanical damage that may show its existence, i.e. one pot noticeably lower than the others. I hope its not this, but im just putting it out there "in case".

[Don-lo]

Good sound pickup! It sounds very normal for a GS with a few miles on it. Mine sounds that way. A new cam chain may help, or it may be that cam end float. I wouldn't worry about it unless you see aluminum powder in the oil.

[ianralph]

Thanks to everyone for the helpful suggestions.

It's interesting that the problem started after I replaced most of the cam chain guides. On the original cam chain guides the chain had worn "tracks" that would have kept the cam chain centred, thereby restricting lateral cam movement. As soon as I put in the new cam chain guides, without the "tracks", the problem surfaced, maybe because the lack of tracks allows sideways movement of the cam chain and hence the cams.

I'm going to test this theory by putting the original guides back in.

I'm also very impressed by the solution published by Ian Grant (49er) and pointed out by Steve - an innovative and thoughtful long term solution.

This forum is a great resource. Thank you.