I had two problems. Mine is very early bike, and needed a spring replaced early on. The new spring made a HUGE difference in the shifting. They don't have to split the motor for that. and it was SWEET after the new spring. Then about two weeks later, trying to get a wheelie, I MISSED second. This is the other time that 140+ foot pounds is impressive. A friend was giggling about it and reminded me it is like putting a gear in a vise, setting a cold chisel against a tooth, and smacking it real hard with a very big hammer. That time they had to split the cases. I don't recommend missing shifts. :lol:
(On a more happy note I left for New York two weeks after it was fixed and did a nice cross country ride, and another 8 months since then with not a single complaint.