prop for jon boat with 9.5 sportwin

[georgeFa]

65 9.5 hp sortwin lite 14 ft jon boat... manual calls for 8 1/4" by 8.5... will it be faster with less pitch or more?

 

[steelespike]

Re: prop for jon boat with 9.5 sportwin

More than likely it is fine as it is 8 1/4 X 8 1/2 is a standard prop.What prop is on the motor
numbers are usually near the base of the blades.Is the prop in excellent shape?It is important that the motor operate within its rpm range 4500-5,000.
Unless you do an rpm check (a tinytach would work) and speed gps and are sure of the present prop size;there is no way to know if or what prop may help. Be sure to balance any load neither too much bow or stern.trim the motor carefully.raise the motor on the transom to a point just before venting becomes a problem. With your old style gearcase you won't be able to raise it much but every bit helps.Just put 1/4" or 1/2" sticks on top of the transom to hold up mottor till you tighten the clamps. Be sure they have a good grip.

 

[georgeFa]

Re: prop for jon boat with 9.5 sportwin

8 x 7 but its in bad shape but the boat would never plane out with nobody in front of boat

 

[steelespike]

Re: prop for jon boat with 9.5 sportwin

If the prop is beat up it will hold you back.You may be able to get it fixed.
My guess is that unless you are a really big guy and carry a friend or 2 the 7 is too light a prop.
the stock prop should work.
Its not unusual for a smaller motor to have a difficult time planing with too much weight in the stern.Do you have your tank in the bow?Have you tried trimming in a notch?
Is the motor in excellent tune?Does the throttle open all the way.
On that boat it should plane fairly easily and run close to 20 mph.lightly loaded.