I broke my thumb throttle and replaced it. The cable end hooks into a slot on the thumb lever and if it is not seated properly the sled won't power up because the rev limiter will kick in a hold rev's at idle only. The symptoms you see will be; it will start fine and after warm up will idle properly (1200 RPM) No idiot lights will flash showing it's not in limp mode, the gauge cluster will look normal. When you press the throttle the revs won't increase you will get the sound of more than enough air but not any fuel. This is caused by the throttle sensors not reading zero. Anything holding the throttle from returning to zero will cause this. This is a safety feature built into ETEC's so they won't rev past idle if the sled was started with the throttle pressed or stuck open. I have read other accounts of this happening before and no one seemed to know why. I got this explanation from a Tec where I bought the sled. So if you ever have the problem of not being able to get the sled pasted idle, check that your throttle thumb lever is clear of snow and ice and the cable is seated properly.