4 stroking at higher rpm

[TheSignGuy]

Hey my bike 4 strokes a tiny bit at 60-65 kmh I use stock CDI and exhaust..


What is the issue?

I broke 40+ mph enough to make the speeds not keep up

 

[Greg58]

Sounds like the main jet is too large, the needle is drawn out of the jet above 3/4 throttle resulting in maximum fuel flow.

 

[TheSignGuy]

Sounds like the main jet is too large, the needle is drawn out of the jet above 3/4 throttle resulting in maximum fuel flow.

Logical but here's the thing I don't think it's 4ting I think it's like detonating at higher speeds cause it's like a knawing like sound more associated with knock, cause at 50kmh it makes no sound like either I'm not disposing of some of the exhaust completely BTW I am running Lucas at about 30-32:1 a little below 8 oz per 2 gallons by 0.3 oz short of 8 oz.