Right prop for 150 hp Johnson

[chad_steindl]

I have a 1850 fishhawk with a 2000 150hp Johnson 6 cylinder carburated motor. It presently has an aluminum 14 1/4 x 21P prop that turns 5000 rpm WOT. With a full tank of gas, fishing gear, cooler and 500 pounds of overweight fisherman, I run about 44 mph. I want to get a stainless steel prop but don't know if I am turning the recommended max rpm. Does anyone know what the max rpm should be for this motor and what a good SS prop size would be?

 

[jdub2]

Re: Right prop for 150 hp Johnson

According to the iboats prop selector, Max RPM range for your engine is 4500-5500 RPM

http://boatpropellers.iboats.com/Jo...andard&**********=844977273&*******=004803000

You could probably bump it down to a 20" or a 19" pitch to get the rpm's up a bit. Going down a size, in theory, is supposed to give you 200 more WOT rpm, so a 19 should put you in the 5400 rpm range.

All I know about SS props is they don't flex as much as aluminum and will give you different results because of that.