Top end rattle at low rpm, any ideas?

[Turbowaffle]

A week or so ago I noticed a strange rattle I hadn't heard before. It only seems to happen when the bike winds down low, while it's still cold. Once it warms up, the engine idles too high to cause the sound. If I give it a little gas while it's still cold, I hear a little rattle around 1k, but it stops right away.  It also only happens when the engine winds down, not when I give it gas. I can't seem to keep the engine at a speed that causes it to rattle continuously, so I'm thinking it may not be a resonant rattle. However, when I try to keep the engine at the speed that causes the rattle, the engine seems to miss. (at least I think it's missing. I hear kind of a poof sound instead of the normal firing and the tachometer shows the speed dip) . As far as I can tell from listening, it's coming from the top end.  Strange as it may seem, the sound seemed to start happening soon after I changed the oil and filter. I don't know how they could be related, if they are.  It's only got 6,600 miles on it. I checked my valve clearance today, and only one isn't within the .03-.08mm (intake on cylinder 2 is .09mm) . I was going to get some new shims to get the height corrected tomorrow. Any idea what is causing the noise, or other things to check for while I have the cover off? Thanks for your help.

-Chris

[glenn9171]

Cam chain tensioner?

[Turbowaffle]

The clymer manual I have says that it can't be adjusted.  Is there a way to tell if it needs to be replaced?

[glenn9171]

Here ya go.  Fresh topic on this very subject.

http://www.gstwins.com/forum/viewtopic.php?t=4612

[Turbowaffle]

Well I checked the cam chain, and it doesn't seem to be loose at all. Any other thoughts on where that noise might be coming from?

[KevinC]

Check the bolts that hold the exhaust to the head. They have a habit of loosening and even falling out. There should be 2 on each pipe.

Could be the exhaust rattling and leaking?

[Turbowaffle]

Bolts seem to all be tight.