1QwkSport2.5r That is an interesting rigger you have is that an original or an adjusted plan of some sort? may I ask what is wrong with the sponsons? I followed your build on the SI3, quite interesting and I also watched the vid that thing moves, how's the turning at speed? Here is a thought if the motor was inverted and the hull modified to have a 1" deep divot for lack of better terms the CG would be lowered considerably. I wouldn't be one bit surprised that the outrigger will do in excess of 60 without too much difficulty. Thanks Jeremy_H unfortunately I have promised that hydro to my son and it has been downgraded to a TT 46 so it'll be a little more fun for the beginner, too much speed for the new person can be a dangerous thing for all concerned. I do have several motors including a couple 90 4 strokes without a home so a new build in the future is a great possibility once an idea pops into the old grey matter! Has anyone used 4 strokes and power response is there a great deal of difference in response? I have the motors for a couple of planes that I have lost interest in and likely going to part with them, I guess I could always sell the 4 strokes and get a 2 stroke of whatever size needed. Another option that has occurred to me is has anyone tried a PTO and placed the engine down in the bottom of the hull?