Now I may be mistaking..... but if the banshee is at full throttle and it magically jumps into gear, dont you think that you would be chasing it down the street? Did you do anything with the shift forks? I have never heard of anything just deciding to jump into gear. Let alone just die when it does. that thing should be running WOT till it either blows up, runs out of gas, or hits something to make it stop. Plus I think that I would have killed it before it had a chance to get to WOT. Its not to good for your top end. But about the slow revving up. I had the same problem for a while. Come to find out that my throttle cable was screwed. Try to replace the throttle cable, or just make sure that you reinstalled it correctly.