I bought a 1985 VMax that came with 4 K&N filters on the carbs, no airbox. I Dyno'd the bike and was shocked at the 80 RWHP. If I go full throttle in any gear, below 4500 RPM, the bike breaks up, all the way through top end. If I go full throttle above 4500RPM in any gear, the bike runs great...