What Prop should I buy?

[PontoonJo]

Bought a great used 1993 24 foot Smokercraft Pontoon with a Mariner Magnum 40HP. The prop is damaged & I want to replace it. Looking for best engine performance & as much speed as possible.... Recommendations?

 

[Silvertip]

Re: What Prop should I buy?

No benchmark data = no possible way to respond. Your best bet is to actually look at the prop for a part number or diameter and pitch numbers. They are stamped into the barrel of the prop or on the hub behind the prop nut. The best prop is one that allows the engine to operate at or near the top of the manufacturers wide open throttle RPM range with an average load. Without a tach reading at wide open throttle we, like you, can only guess. Since that's all I can do for you without any data, I would guess you could take advantage of a 14x9 four blade pontoon prop from Mercury.

 

[PontoonJo]

Re: What Prop should I buy?

Thanks Silvertip.... New to boating, You can see how much I really need your help... Engine 1995 Mariner Magnum 40HP, 4 Cylinder, 2 stroke, Min WOT-5000 Max WOT -5000, spline count 13. Stoming badly here can't get to the prop as boat is in the water. thinking stainless steel, but no clue on the pitch.........

 

[steelespike]

Re: What Prop should I buy?

Thanks Silvertip.... New to boating, You can see how much I really need your help... Engine 1995 Mariner Magnum 40HP, 4 Cylinder, 2 stroke, Min WOT-5000 Max WOT -5000, spline count 13. Stoming badly here can't get to the prop as boat is in the water. thinking stainless steel, but no clue on the pitch.........

On what kind of prop; stainless is usually unpainted ,aluminum is painted.

 

[Silvertip]

Re: What Prop should I buy?

The RPM figures you provided are what the engine manufacturer WANTS the engine propped for. The numbers we need are what you actually OBSERVE at WOT. I personally feel that it is unnecessary to put a stainless prop on a pontoon for cost reasons and the benefit in performance is not usually worth the extra money. Pontoons and work boats are hard to push so props designed for that service are best all around.