Get rid of that Campbell's silencer!!The description is the same as how my C Comet goes. About half throttle, then nothing more.
Same main jet 200, same riders weight.
Differencies is that I'm 5" taller and have a 928 Concentric. Campbell silencer and 7.3 compression.
No idea what cam in it. No mention of air filter, I have a KN-filter.
If you solve the problem, I'd be happy to make same mods.