Hello world !
My bike currents setup : pinasco 177 with pinasco crank, si 24/24 autolube carb with polini venturi, 23 teeth cog, stock ignition, pilot 62/160 - main 120-160-BE3, NGK B6ES Spark plug
Testing it on WOT, at third gear it would scream it way to 90kmh. Shift to fourth, it would goes to 100kmh and then it would feel like it losing power at half throttle. I give it more throttle but it would bogg down even more, the rpm could not go past 3500rpm. Scared of seizing the motor, I backed out and come up here, asking for some knowledge.
So, what could I do to fix this. This same bike with this setup used to max out at 130kmh with a leaked fuel tap on the same stretch of road.
Low RPM smooth as silk and idle beautiful. Third gear WOT feel great. Just the last bit of the fourth gear
Here is a picture of the spark plug after the pull and just a picture of the bike