strange noise at full throttle

[hmin7186]

hi.. i think i'm quite done with the jetting and i've got 1mm needle shim and 80 main jet... but the thing is at full throttle under load, there's some rattling noise coming from the engine... it only happens when the engine is under load (i.e. one the street not when the wheel spins freely on a kickstand) so i can't exactly tell where it's coming from.. but i think it's somewhere around the valve cover area... do you have any idea what this might be?
i thought it might be engine detonation so i tried higher octane gas to make sure but that didn't make any difference... i tried other jets.. but still same thing... let me know if you have any ideas... thanks

[Dandy Dan]

Dans Guesses:
- One of your valve gaps is too loose. You'll get a buzzing noise with this

- Loose bolt somewhere. Look around whereever you've been playing.

- If you've had the valve cover off: did you drop a bolt/shim etc? Use a magnetic to get anything out.

I've had my engine running from way to rich to super lean in a huge variety of temperature (-35C - 31C or roughly -30F - 90F) and i've never had a problem with detonation. I've used all different octane levels and even tried octane booster (waste of $) to see the effects. I've never had a detonation issue and i doubt that's whats wrong with yours.

Because the problem only happens on the street my guess is that something, somewhere is loose and when you're rippin down the street it's vibrating.