The specs show a 32mm OD and a 55mm pitch. As for as the batteries go, doesn't LiPoly batteries have much more running time than a NiMh? I'm kinda lost but I like researching to find the info I need to do things myself, I just can't find the info, that's where you guys come in. I will probably be asking many questions in the next couple of months. BTW what would you guys recomend for mods to this motor? I've been looking at different motors and can't find any with a 3mm shaft. How would I go about solving fitment issues such as this? I don't want to go and spend alot of money on a motor that cannot be installed into my OB. I this boat goes 15mph stock, how fast could I realisticly expect to make it?