1992 tracker partybarge 21dlx prop

[regal 182]

I have a 21` party barge pontoon with a 70hp evinrude lightly loaded im only getting 4200rpm and 16 mph on gps.I currently have a 13x19 13 spline prop and need to know how far down I need to go in pitch to achieve 5800rpm

 

[steelespike]

Do you know the gear ratio of the motor? Educated guess; A 11" pitch 4 blade should get you about 5800 rpm. @ about 20 mph.
Lugging at 4200 is bad for the motor.
Keep in mind this assumes a correct setup and a healthy motor and with pontoons vastly different
results of similar setups occur.

 

[regal 182]

Ok I went with a 14x13 and am getting 5600rpm and 20mph (gps) im happy with it..thanks for the reply