prop help needed please

[cuzzx]

I have a 20ft pontoon that I just put a 1995 mariner 75hp motor on. It had a SS 13x19 prop. The Toon runs good at 2000rpm, half throtle. When I give it full throtle it goes up to 3000rpm and seams to be jumping/slipping type feel and looses a little speed.
The motor is level with the water and water line is where the lower unit bolts on at. Have tried different angles of the motor but this seams to run the best.

What would your suggestions be for a good prop, either alum or SS ?

 

[cuzzx]

Re: prop help needed please

thanks guys for all the help.
i think that this site is the greatest and you guys are great also, thanks again for all the in put and help.

 

[K.P.]

Re: prop help needed please

Sarcasm eh?

19 pitch is WAYYYY too much pitch for that rig. Lugging that motor at that low an RPM at full throttle is going to ruin it quickly. I would guess you need to be looking more along the lines of an 11 pitch. But it's hard to tell because the current prop is so far off. Find a shop that might let you try a couple different pitches.

When you mounted the motor, did you put it all the way down on the transome? It may be better to raise it a couple bolt holes but no more than that.

No need to go with stainless on a pontoon, aluminum should be fine.