Need hole shot help, prop advice.

M

microwiz

Cadet
Joined
Jul 24, 2004
Messages
7
Ok this is kind of a follow up post about my low speed 32mph but it looks like the speedo is not working correctly, possibly because my smart tabs are mounted right next to the senser so I have no idea how fast this boat is.<br /><br />My engine WOT is 4200-4600 however the best I can spin the prop is 4000 so I was thinking about going down to 16 or 15 pitch for a better hole shot. I had 3.5 people in the boat and it took forever to get the person up on ski's<br /><br />Based on this information would it be better to go to a 15 or 16 pitch prop?<br /><br />Also can you just pick up any 15X(15,16) prop or is there something else I need to know?<br /><br />Thanks..<br /><br />1995 17.5 ft crestliner sportfish, 3.0 120hp IO volvo penta SX <br />15X17 Prop
 
Boomyal

Boomyal

Supreme Mariner
Joined
Aug 16, 2003
Messages
12,072
Re: Need hole shot help, prop advice.

I guess they say it's about two hundred rpm for each inch of pitch change. Based on that I'd go for at least a 15 pitch.
 
Mark42

Mark42

Fleet Admiral
Joined
Oct 8, 2003
Messages
9,334
Re: Need hole shot help, prop advice.

microwiz,<br /><br />The only advice I can add is to check your existing prop to see if it is cupped or not. It's cupped if the trailing edge of the blade has a small lip that gives it a better "grip" on the water. That little lip makes a big difference. If you have a non-cupped prop and go to a cupped prop add 100 - 200 rpm loss due to the additional drag caused by cupping.<br /><br />I went from a 13 pitch non-cupped prop (original OMC) to a 15 pitch cupped prop (Hustler) and dropped about 600 rpm.
 
R

RatFish

Chief Petty Officer
Joined
Jul 29, 2003
Messages
647
Re: Need hole shot help, prop advice.

Two words... Stainless Steel
 
W

walleyehed

Admiral
Joined
Jun 29, 2003
Messages
6,767
Re: Need hole shot help, prop advice.

I'm going to make a guess here and say that beings your rig is a 1995 model, good chance you have a cupped prop, and I'm not sure there were any un-cupped props designed for the SX Drive.<br />But, as Mark says, take a look anyway, then you will understand what he is refering to.<br />With the 15X17 you have now at 4000, I think you can expect about 500 RPM more with a 15X15 or a 15-1/2X15, which should put you in good shape.<br />And, as Ratfish posted, I would also recommend SS, and stay away from the Ballistic SS by michigan wheel....great conversation piece but bad for boat propulsion....
 
W

walleyehed

Admiral
Joined
Jun 29, 2003
Messages
6,767
Re: Need hole shot help, prop advice.

That would be OK....Great price.<br />The Ballistic is the one I would stay away from...
 
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