Sounds like a diesel.......
I've got around 70 miles on my motor now. At times it sounds and performs sweetly but at lower revs/speed it sounds cluncky like a diesel motor.
I'm running 25:1 mix and on my second gallon. Would lowering the mix to 30:1 or 32:1 help. Spark plug is a B7H set at .25. C clip on #2
When running towards WOT it also seems to be losing power, top speed at the moment is 30.2 mph.
(all this converting from metric to imperial is hurting my head.....)