Cam chain rattle ?

[SAFE-T]

Bought an '07 GS500F for the spouse last year - just in the process of "fitting" it to her a bit - lowering linkage for rear, seat cut down, raised front forks, etc.

Anyway....the bike had a slight top end rattle noise when you revved it just off idle. Seems to go away under constant throttle but picks up slightly when under load up until constant throttle.

Did a search through the forum and it sounds like a cam chain tensioner problem, although the bike only had 914 km on it. Sounds like a relatively easy fix but couldn't find a "how-to" on it. 

[fred]

The cam chain tensioner is automatic. There isn't really any adjustment to it, so if it stops working, you're just supposed to replace it...

I find it funny that you are lowering your bike and shaving the seat when mere moments ago I was reading a thread about someone trying to unlower their bike and deal with a shaved seat....

[Big Shot]

Remove the plug on the tensioner.  Behind the plug you'll find a flat head screw used to release the tension on the cam chain.  I think it's a standard left hand turn to do that but can't remember for sure.  You'll feel pressure against your turning force from the spring, but other than that, it should turn freely.  If you are using a lot of force and the screw isn't moving you're going the wrong way.  Like any other screw.  Anyways, once you've turned it a couple of times, release it and it should snap back into the place it was originally.  If it does so, it's fine.  Another way you can check the cam chain tension is to remove the valve cover and poke your finger on the chain.  It should be taunt.  If it is, your cam chain tension is fine.

Chances are, it's not your cam chain tension and something else.  One thought would be the cam/cams side play.  It would cause a ping/ting like noise and behaves similar to, "The bike had a slight top end rattle noise when you revved it just off idle.  Seems to go away under constant throttle but picks up slightly when under load up until constant throttle." that you've explained you're experiencing.  The fix for this is nothing.  It's a design flaw in the head.  It is annoying until you realize it's not a problem.  And the good news is it shouldn't cause any damage.  Or anything worth a consequence while you own the bike.  Many have reported it goes away with time.

I had this problem on one of my bikes.  It was a little more intermittent than what you've described but still similar.  With the valve cover off i grabbed onto the cams by their gears and tried to slide them side to side.  The intake cam wouldn't move.  Or move with a reasonable amount of force.  The exhaust cam however did.  And while doing it i was able to reproduce the sound.

You've said the bike has 914km on it, have you checked the valves clearances and re-torqued the bolts on the head and cam bearing caps yet?

It's time.  Along with a bunch of other stuff.  Refer to your manual.

If none of this does it for you, i suggest you get a bigger, better, Buddha approved hammer like this one  http://www.youtube.com/watch?v=9j8EEc8yETM


Should do the trick - Bob!