This engine comes with the jammin truggy and is it any good? Are there any problems with it or any problems with the start-shaft system?

It is a good motor for a RTR. In the recent rtr truggy tests it was the best motor of the group. It is a bit capped off at the top but has nice bottom end. The only problem that I've had is with the shaft start one way bearing. It keeps on freewheeling for some reason. I took it out and cleaned it with some contact cleaner and it worked for about 5 minutes then started spinning again without turning over the motor.