The numbers I gave you are from TH parts page for the RR so they should be right. 28 mph is fast for a little boat. Right now it turns on a dime but at that speed it may flip, at least it will self right if it does. Should make for some exciting boating even at 17 mph cause right now it's about 12 mph. The radar gun I got is very accurate so I'll let you know the speed with a stock motor then with the BL. Hopefully your numbers will be close. Thanks