So I have 2 brand new tilt/trim pump motors and thought about making a set of matching electric longboards since products like Boosted Boards seem to have become fairly popular. I am not too sure whether the tilt/trim motor would be strong enough though, they are a decent size motor though. But it got me thinking what size is required for an electric longboard? The main problem with the tilt/trim pump motors is that I can't find specs on them anywhere, just specs for tilt/trim pump assemblies they are off of, but nothing about the motor itself other then SAE J1171 Marine rating. Because of this I thought of buying another DC motor to do the job. (Picture of tilt/trim motor) The constraints for me is that I have a couple 12 - 24v 100A motor controllers already, for brushed motors only. As well, I want to just pick up a couple cheap $40 12v, 24AH Sealed led-acid (SLA) batteries from the local Ace Hardware and run either a 12v or 24v motor. Options on eBay for affordability purposes range from 12v, 24v, 90v and 180v dc, obviously 90v and 180v are out of the question. Looking through the 12vdc and 24vdc motors, there are many fractional HP motors available. I was looking at something like this; http://www.ebay.com/itm/172252712203?_trksid=p2055119.m1438.l2649&ssPageName;=STRK%3AMEBIDX%3AIT Running 1/4 HP at 24v, would 1/4HP be enough though? I know electric motors HP ratings are lower then petrol engines, a 6.5HP petrol go kart runs about the same as an identical kart with a 1HP electric motor. If that isn't enough I am thinking a 2/3HP motor from Holley might be better? http://www.ebay.com/itm/361524972024?_trksid=p2055119.m1438.l2649&ssPageName;=STRK%3AMEBIDX%3AIT Wondering if someone has an idea for sizing. I know lots of eBikes and Chinese electric mini bikes and things have 500W motors, so roughly 2/3HP, so I can't imagine I need more then that. As well I don't want it to go too fast (fear of speed wobbles) but if anyone would have an idea of sizing that would be super helpful!