Thanks for the info I thought maybe 40,000 rpm's was a touch much...this boat has a gear drive trans with about 160 possible gear combinations so if I'm way to fast can't I just gear back a little or what about the end point adjustment on the radio...cant I turn that back for less speed? Or should I call the boat man back and tell him to order me a 1515/2.5d smooth can. Let me know what you think bro!