Help me diagnose my miss over 4500rpm.

89on35s said
If I had to describe it, it is breaking up, then when I shift and the rpm drops, it's perfect again till it hits that 4500 rpm again.

Cley

I had a 340 once that did that when the plugs "overheated" A new set always fixed her right up.The root cause of that was too-lean running.
My 367 does that all the time......... if I forget to reset the rev-limiter,lol.