Well I was so happy with the mt12 that I went and got the same but rotary. This was sold to me since the owner lost the receipt and the engine was "defective". The engine looks great except for the carb's rotary arm. this thing is pointing straight down and I don't know how to fix this. I tried to loosen the LSN but it is tighter then a virgin. I am afraid I might do more damge than good! Can someone help me!