Looking today at a 90 hp force, seems to me that the twin carbs would fit on my 1994 70HP.Would this be all that is needed to make a 90 out of my 70hp?
I doubt it. Probably just run too rich, due to the different jets. Probably different pistons in a different bore x stroke block, reeds, ignition specs, etc.
I assume you are intending to replace the whole carb, manifold, and reed assembly. Save your money. Those twin carbs will get you about 72-75 HP. The 70 is ported differently and no amount of increased carburetion will add much horsepower. Now, if you dismantle the engine and do some port work------
