setting up merc

[jims3000]

i bought a 1985 merc 150hp for a 17.5ft bass boat and it has a 23pitch prop on it. the last fin on the foot is about even with the bottom of the boat doesnt turn but 5200rpm a guy at a boat shop said that i should raise the motor 1 more hole and that it should throw a rooster tail about as high as the motor.would this be correct.

 

[CharlieB]

Re: setting up merc

Rooster tail MAXIMUM should almost be high as the top of the motor cover, any more is lost thrust. Adjust trim for max rpm/speed.

Motor mounting is generally set such that the bottom flat plate/fin (anticavitation plate) is even with the bottom of the hull, depending upon transom angle and/or jacking plate/setback, the motor may be mounted higher to cut down on gearcase 'drag' in the water IF you are attempting to achieve maximum speed. WARNING, elevated mounting must be sure to not mount so high as to reduce cooling water flow.

 

[Faztbullet]

Re: setting up merc

What type of hull is it?? Do you have a jackplate? Good beginning is to trim engine level and pull a straight edge of bottom of pad. Try to split the water pick-up inlets 50/50.