prop question

[rathrbfishin]

I have a 98 Sea Stealth , with a 98 Yamaha 90. With the average load of boat, motor, gas, equip and people @ wot I'm at 4900-5000 rpm's. I have a 17 pitch prop. I have read that if I prop down to a 15 pitch I will gain around 400 rpm's which brings me to the high end of my motors operating range ( 4500-5500) My question is by gaining those rpm's will that inturn increase my speed?

 

[QC]

Re: prop question

Usually they are fastest in the middle to lower end of the range. The 15" will improve your hole shot, but could slightly decrease your top speed. Also, yoo could end up in an overspeed condition if the boat was lightly loaded.<br /><br />Your existing prop sounds right. If you don't have a spare and would like to experiment then do it.<br /><br />Check out the WOT and Propeller threads in the Engine FAQ section.

 

[SKIEB]

Re: prop question

I have a problem getting on plane with my 200 optimax mercury. I have a 19' NITRO CDX. The prop is 4 blade 25 pitch. When it comes up out of the hole and starts to lay down the prop breaks loose and the motor over rev's. I have to do this a couple of times before I can get to plane. The prop is not broken. I can top out at 80 MPH. after getting on plane. Is there something I need to do to the prop to get the thing to stop washing out.

 

[Dhadley]

Re: prop question

Welcome!!<br /><br />What brand prop is it? And what diameter?

 

[chuckz]

Re: prop question

Not a prop problem, either a trim or motor mounting problem. Provide details of how your engine is set-up and one of the go fast bass boat boys will help you.

 

[rathrbfishin]

Re: prop question

the motor is mounted all the way down. cavitation plate is even with bottom of hull. If I raise the engine will that increase my rpm's ????

 

[JB]

Re: prop question

Outboard Non-repair topic