Prop selection and motor height help

[Aquanut1]

I'm having problems getting the right combination of prop and motor height. The boat is a 1990 Nitro 2000 that measures 20'6" about 1550 lbs with a "V" pad. It has a 1990 150 Johnson Gt. I was told it would devolop maybe 170 hp. When I bought the boat the motor was at the top mounting hole with a planing fin.I took the planing fin off. Out of the 4 adjustment holes for height I'm down to one over the lowest. It is still blowing out but it seams to grab on turns. At idle to the time it planes I'm grabing water and as soon as the bow comes down it starts to blow out. At half throttle with the trim all the way down it grabs on and off taking my rpm's down 400. Has anyone had this problem or is there a correct way to calculate this.

 

[Dhadley]

Re: Prop selection and motor height help

Out of the 4 adjustment holes for height I'm down to one over the lowest.

The holes that allow the lowest mounting of the outboard is the top hole. So can we correctly assume the bolts are in the 3rd hole down from the top hole? We could actually raise the motor up 1 hole or lower it down 2 holes, right?<br /><br />Sounds like the prop may be getting worn too. What prop is it? Is the cup at the tips gone?

 

[Aquanut1]

Re: Prop selection and motor height help

The loner i got from the prop shp is in bad shape but he thought that we would be able to tell if we were going in the rite direction. Hes wrong. I called Nitro to see if I could get any info and they had it all. 5/8" between motor and transom and a 14 1/2 x 24 Raker. I'm antsy to try that. Sad part is Rakers are really expensive. Thanks for the help

 

[red10]

Re: Prop selection and motor height help

aquanut, i have the same prop and motor, i experienced the same thing, see if you can plug the vent holes one at a time, that cured my issue. 2 holes closed, 1 open.