Prop help needed on 1964 Mercury 650 65hp O/B

[tunerauto]

I have a smoothly running 650 Merc on my 72 Glasstron V153.
No insignia on the prop other than a stamped x11 on the prop blades and what looks to be a stamped HAAN 052089 on the inside of the prop shaft.
I pull a wakeboard with this motor ... decently but Im thinking I could get a better hole shot with some hydro foils and possibly different prop.
Can anyone help me identify mine and help me determine what would be better ?
I have no tach or speedo on my boat but am looking at one of those digital tachs that go around one spark plug wire and another wire attaches to a ground on the motor.

Thanx

 

[tunerauto]

Re: Prop help needed on 1964 Mercury 650 65hp O/B

anybody know how to measure a prop to get its dimensions and specs ?

 

[194269]

Re: Prop help needed on 1964 Mercury 650 65hp O/B

Your prop is probably 11 inch pitch, it looks like there is not much pitch in your pictures. Witch brings me to this question. That pitch seems low for your boat, I had a Glasstron 143V with a 67' 650 on it and it no trouble with a 17" prop. May be you should run a compression check on the old girl, it should be between 115 and 125. My friend back then had 68' 153V with a 68' 650 and he could just about stay with me, I could run 37 with mine.

 

[tunerauto]

Re: Prop help needed on 1964 Mercury 650 65hp O/B

Thanx for the info . I thought that 11 probably meant pitch . My prop needs to be a 13 spline yes ? I have plans to do a compression test on my list .

 

[194269]

Re: Prop help needed on 1964 Mercury 650 65hp O/B

The 650 uses the six cylinder gear case, there for 15 spline.

 

[tunerauto]

Re: Prop help needed on 1964 Mercury 650 65hp O/B

thank you 194269