All, I need some quick advice.. I was approached about trading my manual start 1988 Game Fisher 15 HP for a 1977 10 HP Crysler Elec start. I know my motor is sound and has been maintained very well. The Crysler has been maintained, but not by myself but service records are available. question one is, are cryslers HP rating measured at the head or the prop? if so would that put the 10 HP Crysler at about an 7.5 or 8? I know my 15 is more like a 10 or a 12 measured at the head. All being said and done, would it be a decent trade? manual for Elec even though there is an age difference. If the HP rating is measured at the head like my gamefisher, the deal is not going to be going thru. I need all the speed I can get. Please guide me Oh wise ones of the water! I need some assistance on what to do here. I really like the option of electric start but don't want to take a leap backwards just to save from pulling my motor a few times versus the electric start and less HP.