StrontiumEthics,
I was having this problem as well. i knew it had to be extra air getting into the mix but everything i did with the carb only helped very little to solve the problem. then i had an epiphany....what if extra air was getting into the combustion chamber through the connection between the intake manifold and cylinder head and totally bypassing the carb? i took the intake manifold off and discovered that the seal between that and the cylinder head was complete toast! i replaced the gasket and the bike has been running perfect. sounds like your problem is very similar. id bet your gasket is worn to bits.
I was having this problem as well. i knew it had to be extra air getting into the mix but everything i did with the carb only helped very little to solve the problem. then i had an epiphany....what if extra air was getting into the combustion chamber through the connection between the intake manifold and cylinder head and totally bypassing the carb? i took the intake manifold off and discovered that the seal between that and the cylinder head was complete toast! i replaced the gasket and the bike has been running perfect. sounds like your problem is very similar. id bet your gasket is worn to bits.