Hi guys, I have a ZA50 with a basic 70cc Airsal kit, long intake, fancy exhaust, pretty well tuned Bing 14.
It was working amazingly for miles until I developed a crunchy mid range. It's just kucky enough now that I can't get to that higher 2-stroke "nirvana" in second gear.
I know you guys want to tell me to do all the simple stuff right-off the bat, but I did. Checked gap, replaced gas (found a little water and crap), cleaned carb, played with different plugs, played with needle. Still same problems.
So, any fancy theories? Thinking of taking the cylinder off and checking for scratches... ?