I have an echo 21.2cc engine and I raised the exhaust and intake ports but since I have no experience with this I think I might have ruined the engine . it's 170 degrees exhaust duration and 140 degrees intake duration what do you think?
Spark and compression ok.Plenty of fuel to carby,but I suspect this might be where the problem lies.Tried a mate's carby(working) without any better luck.Frustration setting in....!
