Symptoms. starts fine, idles fine (maybe bit lean with basic setup), low to mid revs fine. But on high revs it misfires, slow topspeed and generally bad runnign (generally mixture aint igniting on every stroke... hope you understand. Tried new base gasket, carb gaskets, different carb,plug, coil+wire+cap and better (not new) ring. carb bubble is full of fuel and fatting or leaning H aint curing or even improving symptoms. Plug seems little lean but with lots of WOT driving because testing. It has got maybe 5 litres old 29cc cyl but I saw coating worn around exhaust so it hasnt got much life left, but could bad coating do that kind of symptoms. I am almost ready to buy new mill but since ddm DOTD had that sad 29cc on low price maybe I try that before ordering new.