Tell me this noise isn't what I'm afraid it is.

[Mike B]

My thoughts since there is a noise and poor engine performance, it will require pulling a head off and see what's going on.

I can't see (in my mind) how changing jets, adding more choke, etc, would reduce a bearing/wristpin noise.

[Old Henry]

Originally Posted by Mike B

My thoughts since there is a noise and poor engine performance, it will require pulling a head off and see what's going on.

I can't see (in my mind) how changing jets, adding more choke, etc, would reduce a bearing/wristpin noise.

I didn't have poor engine performance except when I pulled the choke out enough to cause it when I was checking to see if it was just premature detonation which, along with larger jets, can be and is reduced by enriching the mixture. Of course, when none of that worked I realized it was something else that wasn't solved by any of that. Using high octane fuel can also reduce premature detonation. Tried that too without benefit.