Trichamp
Member
Mainship 390: currently looking at different age Mainship 390's. Question, how do you determine if the prop is of proper size for the respective boat? Thanks
Mainship 390: currently looking at different age Mainship 390's. Question, how do you determine if the prop is of proper size for the respective boat? Thanks
The Mainship 390s were delivered with Cats, Yanmar 6LPs, Yanmar 6LYs, twin Yanmar 4LHs. All have different maximum rated hp rpms.
That only works with a clean bottom. Any growth will slow the boat down and it won't be able to hit the rated RPM.........
Then take it out, warm it up and run it for a few minutes at wide open throttle in gear. It should be able to hit maximum rated rpm plus maybe another 100 rpm. If it hits max wot rpm + 200 then it is underpropped. If it hits less than maximum rated rpm then it is overpropped and you are a candidate for a prop repitching job..............