Propeller choice for 150HP Johnson

[sludgemonkey]

Just changed the engine on my boat from a 90Hp Yamaha with a 1375X13 propeller, to a 150HP Johnson equipped with a 1425X23 propeller. With the Yamaha i could reach 5500rpm , but i do not seem to get above 4300 with the Johnson.<br />The boat is around 2200 lbs, and I think the current propeller has a too large pitch. Idling speed is indeed high, and top speed with the Johnson is more than high enough @ 4300rpm. It seem that the engine is running comfortably at around 3400 rpm, but the speed is a little high then. Any suggestion for alternative propeller size? Is 1425X23 too big?

 

[Jquest]

Re: Propeller choice for 150HP Johnson

Try 14.25x19. Either that or 15x17. You definitely have too much bite with that 23. The 150 should be doing 5600 at wot. That is what you're shooting for.

 

[JB]

Re: Propeller choice for 150HP Johnson

Moving to the Prop Forum

 

[sludgemonkey]

Re: Propeller choice for 150HP Johnson

Thanks.<br />What is the noticeable difference between 14.25x19 and 15x17?

 

[Ron G]

Re: Propeller choice for 150HP Johnson

Those numbers sounds off to me,are you sure your tac is correct??That 150 should be turning 5600 easily i would think with a 23p.