I have a 1994 Mercury Mariner Magnum 40hp, 30 jet outboard 4cyl, 2 carbs, 2-stroke oil injected. It is on a 16' fiberglass Key Largo. I can throttlr up to 5500rpm and I am topping out at 8mph, not even enough to plane up. I have changed the prop and hub as 1 unit.(10 5/8, 12 degree) Motor sounds find, doesn't skip or bog. Even still, I cleaned the carbs, put a fuel pump kit in and changed the prime bulb and hose to the motor. Used non-ethanol fuel. Drained the lower case oil and looked clean. Any ideas why my speed is so low?
Thanks
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