Rattle at around 5K RPM

Hey all,

I'm looking for perhaps a bit of guidance. I would like to try and find out where my rattle is coming from. It starts at about 4900RPM and goes away after about 5500RPM. It sounds almost identical to the rattle my Subaru used to make when the heat shields were vibrating against the exhaust.. :ohmy: I hear it in all gears, whenever I hit that RPM range

what sucks is that i can't reproduce the rattle unless i'm riding the bike. gettting it up there while it's in neutral doesnt produce the sound.. weird? so because of this i can't really tell where the rattle is coming from, but i'm pretty sure i've ruled out the exhaust! :lol:

Anyway, the bike starts and runs fine except for this rattle.

I found a separate thread HERE regarding what to check out:

- Drive/Cam chain tension issues
- Leaky intake manifold
- Valve lash
- Carbs out of sync

as stated in that thread, some of these things cause rattles that appear only at idle or low RPM, but it's probably a good thing for me to check out anyway. i will probably start out with checkin the chain tensions, and then go get my carbs properly synced. as i said, the bike runs fine, but it could probably run a little better! if neither of those things fix it, i'll have to resort to taking that top end off and takin a look around for the other two things.

anyway, is there something else i'm missing that i should check? any tips/criticism/condolences/well wishers greatly appreciated!

I had a rattle at about 4,000 rpm. Drove me nuts. Then I found the bolt securing the gastank was loose.

Can you isolate what side its coming from??? I had a rattle like that a few years ago and found it was the big gear that the starter drives under the stator cover... It has shims behind it that were worn and the gear would rattle at about 5000 rpm, but only when I was riding the bike, reshimed it, no more rattle...

Hope this helps

1045

excellent, thanks for the tips guys.. i'll check out both of those things as well!

cheers

Because your rattle only happens at a specific rpm range, it might be something easy...something that resonates when your engine (and your bike) vibrates at a certain frequency. But finding it is maddening!
Here's what I've found buzzing on mine:
1. Clutch & Brake Levers (shim with teflon washers)
2. Foot Brake Pedal (rattles against the stop/adjustment nut)
3. Loose Header Pipe (crush washer needs replacement)
4. Mirrors
5. I don't have one, but I've heard that the center stand can rattle

Problem is, with the wind and engine/chain noise, it's hard to isolate the sound. Not to mention your sitting on a moving bike, so it's hard to get you're ear in the right place.
But try to eliminate the easy stuff first, if you can.