Do I have a problem?

[mercuryblues]

I have a 1966 merc 650 outboard.WOT is 25-27 mph.The boat is a deep v-hull fiberglass boat 15 ft.someone put a sloppy fiberglass patch right on the bottom of the boat where the v comes together,so I think I should sand that down and see if I can do any better and also see if that speeds me up any.I also want to check into a new prop as the old one is beat up a little,the ser # on current prop is 48 32390A3 15P.Can anyone tell me what prop would be best for speed for a boat as described above,also besides prop any other tips for speeding boat up,(besides bigger motor) Thanks in advance for your time and replies.P.S. is 25 mph about right for my motor??

 

[Hooty]

Re: Do I have a problem?

If ya don' have a tachometer, mb, you're gonna need one. The speed of the boat is only part of the equation. We're gonna need the engine speed to. Here's a source for an inexpensive tach.<br /><br /> TinyTach <br /><br />c/6<br />Hooty

 

[rickdb1boat]

Re: Do I have a problem?

mercuryblues <br /><br />I can tell you this. I had a 1967 650 on a 15' Wellcraft that I refurbed and it had a 15" pitch prop. It would top out at 34 MPH at 5500 RPMs. Wasn't a deep V, but you should get better than 25 MPH with your set-up. As Hooty said, get the tiny tach and go from there. Boat weight has alot to do with it,too. Mine looks like this, except I have a Johnson on there now, as my 650 went south. I still get about 27 out of the little 28HP Johnson.<br /><br />

 

[mercuryblues]

Re: Do I have a problem?

Ahhh,yes I will check into a tach,what should mine do wot? Also are they easy to install? Thanks again guys.

 

[Solittle]

Re: Do I have a problem?

What does this fiberglass patch cover? If a crack I would be more concerned that it was fixed correctly than how fast it will go.

 

[sloopy]

Re: Do I have a problem?

Decarb the engine first, you should get around 4500-5000rpm wot.