ORIGINAL: krproton
Guys,
when I advance the throttle after extended down lines (when the throttle was at idle) the engine hesitates and sounds like it's going to quit before it "spools up" again. It always sounds like it's going to quit, but never has - just kinda unnerving.
My needles are set so at full-throttle it runs perfectly and at half-throttle or a little below it burbbles/four-strokes (if that has anything to do with it which I don't think it does).
Any suggestions?
Tim, nearly always a "throttle up" hesitation is too lean a low needle. It is easy to miss the sweet spot, since the low end affects the high, you can be tweaking away and get the high "perfect", but the low is lean.
My "test" is to leave a fully-warmed up engine at it's sitting-still idle....if it gradually speeds up, the low end is lean, if it slows, it's rich. Very much like glow motors.
I try for a solid idle without variation, even if left at idle for 30 seconds or more, then advance (dump) throttle to full immediately. If your low end isn't right, you'll see it RIGHT there.