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Rattling noise


Dixie

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Hi All,  Sorry more questions.  I've been out on my 79 GS 750 today and wound it up a little to see how it went.  Got home and noted when sat on the bike there is a metallic noise, sounds like top end, but when I put it on the side stand it disappears.  Sounds like a cam type noise, but this is just an educated guess.  The noise isn't constant, as in its rattling its nuts off,  it sounds like every couple of seconds at most.  Any ideas.:(

 

 

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I've spent the evening researching and the noise looks like cam buckets or shims, would worn shims make this kind of noise?   It only appeared after a good run.  Shims are cheaper than buckets so fingers crossed.:| What do you think?

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Is that one of the engines that suffers from cam walk (side  to side play)?

Never owned a 2 valver, but I’ve heard of the issue on several ocassions.  One of its hallmark indicators are that when the bike is tilted, as on the side stand in your case, it goes away. I’ve read that flipping the half moons on the valvecover gasket takes up the slack and stops it. 

Again, no personal experience, just passing along what I’ve read.

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If it's cam end float, just live with it. Sounds like it may be, and there's no need to worry bout it. There is a proper fix, but its not really worth bothering with. Check out the GS Resources website.

Balance the carbs - that will help with noises, however do all the other service items first, including shimming the valves.

These are not quiet engines!

By the way, if  the charging system hasn't been sorted, make sure you ride with the lights on!

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 The original regulator  rectifier sends unused / excess power back to the stator which will cause it to run hotter, and can lead to its failure. Running with the light on will use some of that power.  At a minimum its good practice to inspect / clean all wiring connections. Bad connections will run hot and can melt plugs, etc. 

There are volumes of info on the subject over at GS Resourses. 

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i'll vouch for cam float on a gs1000 - observed as previously noted - move the bike from side stand to upright and it comes and goes - my foggy memory from a long time ago is - sounds like a random dull knock, where as a worn bucket has more of a consistent higher frequency rattle

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OK, so I took the bike out for a short run tonight and initially no rattling. As bike warmed up it reappeared. Lean it over to the left or right and its stops. Turned bike off for 10 mins and it had gone. Rode it home and it came back.  Did the old long screwdriver as a stethoscope routine and I think I've traced the noise to the casing above the cam chain, assume it's called the cam chain cover, educated quess. Could it just be the cam chain. I have read that if you slaken the adjuster and then retighten this can cure it. Before I try that I thought I'd run it past you guys in case you know any reason why I shouldn't mess with the adjuster.  You know what they say everyday is a school day:$

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cam end float. your hear it from the area where the cam sprockets are. if it stops when you lean it from side to side, then that would indicate that the cams are moving from side to side as you lean the bike over. common gs problem, if you dont do something about it in the next hundred thousand miles then theres a chance that it might become marginally worse......

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Johnr,  100,000 miles:D that's good news at least its not a terminal issue.  OK then so whats the best way of dealing with it, i'm on the spectrum according to my better half,  you know the type, spanners in order, a place for everything and all that jazz.  The noise will drive me mad so i would like to sort it, any tips.o.O

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32 minutes ago, Dixie said:

Johnr,  100,000 miles:D that's good news at least its not a terminal issue.  OK then so whats the best way of dealing with it, i'm on the spectrum according to my better half,  you know the type, spanners in order, a place for everything and all that jazz.  The noise will drive me mad so i would like to sort it, any tips.o.O

You can't.

Well, you can, see the above posts re: The GS Resources website. Have you checked that out yet?

The fix is laid out clearly on there, have fune if you want to do it ;) Seriously I'd suggest you leave it alone.

Also, don't touch the cam chain adjuster. It's automatic, and unless it's failed completely (you'd know about that) it requires no attention.

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Nice one, i have just downloaded a 10 page doc which discusses a fix, but it looks a bit technical and very involved.  I have also found mention of Camshaft wave washers, has anybody used these and if so where can you get them in the UK.   

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3 hours ago, Sheep said:

Just put it down to the bikes character...something most modern bikes do not have....it makes older bikes more interesting

Rattly cams=character

Oil leaks=character

Clutch needing man hands=character...

:)

brakes that don't work

frames that can develop terminal wobble randomly

suspension with more bounce than an easy ladies  nicker elastic 

tyres that are narrower than a Scotsman's wallet

and just about enough ground clearance to not bother getting too excited about leaning off

aye - and they were / are great fun - with all the above, as you suggest Sheep a wee head rattle is the least of our concerns 

 

 

 

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You're all right, I get it and if I can't sort I'll live with it, but I took it to a mate of a mate who's an oldskool mechanic and he's worked on loads of these when they were new and now they are classics.  He's having it next Thursday and he's gonna have a look. The sound coincides with the cam chain rotation so worth looking at. If he can't sort I'll stop my fecking whining.  If he sorts it then more info to feed back into the forumO.o

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