is my prop right or wrong?

[wwcj101]

1988 18.6' venture bass boat not real sure of weight. 88 johnson gt150. normal load 700lbs+-. prop is a shooter 13 1/4D X 25P 4 blade stainless. 55.4 mph gps @4850 rpm...... should it be faster? should rpms be higher? should i just leave it alone?

 

[hwsiii]

Re: is my prop right or wrong?

Wwcj101, I show your prop slip to be 10% and that is exellent, but you are lugging the motor bad, you should be turning about 5,800 RPM as Dhadley says, with todays gas. You will need to hange to a 21" pith prop in the same exat prop you are running now to get that. You are very lose to the 2 to 1 Pith diameter ratio with the prop you are running now, but it is lugging the engine too muh. You will probably lose a ouple of miles per hour, but your engine will last muh longer and run better.

Prop hange

H

 

[wwcj101]

Re: is my prop right or wrong?

thanks for the info hwsiii. it may be awhile before i can come up with the scratch for the 21p. but it gives me something to look forward to.