How slow was the 18, did it pull at the top of the rev range, i took my race bike to the track and it was pants, very slow, made the 21 i had with me feel like a rocket ship, i have since discovered that the servo or part of the pgm is knackered, so to solve my problem i have manually moved the servo round to keep the power valves open, it means crap bottom end, but should fly up top... have a look and see if you servo is working, as long as you have a good battery, it should work while reving the bike, listen for the noise and look down between th fairing to see if its moving when you gas it!! might help....