You are really pushing that motor with 8 cells and the stock 32mm prop.A X435 would make it worse-I would go to a X430 which is 30mm.The proboat shaft is 3mm which makes prop selection difficult-less cells or a smaller prop will reduce amp draw and run cooler.I have run the same shaft and prop on a 15 turn Orion motor on 6 cells and it only gets warm.[8D]