What size prop is this??

[hunter703]

I purchased a used 30 hp Mercury a couple of years ago. I think the motor was built in the mid 90's. The prop that came on this motor has numbers on the inside that don't mean anything to me. The numbers are F10.63x12p. Can anyone help me? I assume it has a 12 pitch but other than that ?? On the other side of the hub there is a 27 and on the opposite side of the splined hole there is an A. On the same note I purchased a spare prop from a dealer one day as I was passing through and he sold me a used prop he stated would work on my boat. I didn't use that prop that year and when I did it didn't work well with my setup. ( Slow and hard to get it up on plane.) The numbers on that prop are 48-73/40-15. It also has a 21 and a A on the other side. I run a Alumacraft 16/52 tunnel hull. I duck hunt and am probable carrying to much gear. I need more speed and need to plane out. I know what your going to say don't take so much gear. Not an option! HELP!!

 

[usskydvr]

Re: What size prop is this??

A 10.6 x 12 is a normal prop for that 30HP. Are you sure that other one doesn't say 48-73140? That would be the Mercury part number for a
10 1/8 x 15 prop. The 15 pitch would get you more speed provided that your engine could turn it with your load. The 12 will give more power, but less speed. If you can't get on plane with either of these two then you simply don't have enough power.

 

[hunter703]

Re: What size prop is this??

What is your oppinion could I go to a size in between these two props?

 

[usskydvr]

Re: What size prop is this??

Yes, you could go with either a 13 or 14 pitch prop.

 

[steelespike]

Re: What size prop is this??

You really need to know your rpm and speed gps is best.a Tinytach is about $47 and easy to install.It will fit any motor with the same number of cylinders as yours without regard to stator poles.While the 12 could turn out not to be the one; it should plane the boat with one aboard so we could get some numbers. In the meantime specs on the boat would help.dry weight,typical load in pounds?
The tunnel may make it difficult to plane with a load.We used to easily plane our 18 ft utility with about 1100lbs total weight with about a 15 year old 25 Gale.