I am wanting to make this motor a 50 hp.I have done so far, 50 carbs with 49D hs jets, upper carb #31 ls jet, lower carb # 29 ls jet, 50 reed stops, CCMS fiberglass reeds. I have seen no performance gains after these mods. Plugs are QL78YC I looked on CDI website and they recommend QL77JC4...