Join Date: Nov 2009
Location: Lander, Wyoming
Have you ever had the carburetor off? Was the idle mixture tamper-resistant cap removed, ahead of the float bowl? Do you know how many turns open it may be from lightly seated?
Exhaust after-fire or popping can be an indication of slightly too lean of idle mixture, unless your header pipe gasket is loose or burned out.
A slightly lean idle mixture would be even more noticeable during cool autumn temps. 2 turns open is usually about correct + or - a 1/4-1/2 turn, open is richer.
Modify at "YOUR OWN RISK"!
Still riding my 1987 KL650-A1. 85,000+ miles & counting