J/30 Class Association Forums J/30 Forum The Boat, Sails and Equipment Prop pitch

I need a new propeller, does any one know the proper pitch. I have a 3/4 inch shaft, and 15 inch diameter Martec. The hub is splitting at the pin and according to the info I received when I bought the boat it cannot be rebuilt.

From the J/30 Class Rules in the specifications section at the bottom:

Propeller: Standard propeller is folding two-bladed Martec Design Number 23780 - Right Hand, 14 inch diameter, 14 pitch elliptical for 3/4 inch shaft.

Is it true that the Class spec for the prop was created for the 13 hp Yanmar. And if so, isn't the 14p a bit under powered for the 15 hp (1984 model)as noted in another discussion. I feel the 14dx14p is under propped for me. ie. Black soot on transom, 6.6 kts in smooth water at 2800rpm

Soot on the transom in relation to prop means that the engine is recieving more fuel than it can burn. You may have more prop load than the engine can handle,therefore it smokes instead of burning all the fuel. The proper load is the prop that willallow the engine to turn max allowable RPM at full throttle. I had a prop that was perfect when loaded for racing,but was too big when loaded down for summer vacation. You can call me at 808-333-5068 for more help.