Merc Prop Selector

[youngboater]

I was looking at Mercurys website and ran across the prop selector and it said I should have a 23 inch pitch prop for overall good performance? I am currently using a 19incher which came with the boat. I am running fine as far as RPMs go but maybe I could improve on the overall boat performance? It is a 2002 75 Merc 2-stroke 16.5 foot Aluminum Fishing if you want to look it up at their site. What do you think about this? Does a 19 inch prop sound about right? It says about 41 MPH estimated top speed. With GPS I am only getting about 32-34 MPH. The weight is evenly distributed and she weighs about 1500+people. THX

 

[rickdb1boat]

Re: Merc Prop Selector

What RPM's are you running now. That's the important thing to know for starters...

 

[youngboater]

Re: Merc Prop Selector

4750-5250 is the recommended RPMs and I am about 4900 RPMs. I know that is fine as stated above. I was just wondering how credible the Merc. Prop selector is and if I should change props? All the recommended possible prop pitches are higher than my 19inch and I don't go near as fast as the say I could?

 

[roscoe]

Re: Merc Prop Selector

Your speed and performance sounds about right to me.<br />I don't know about their prop selector, couldn't get it to load. Perhaps they are figuring on a lighter weight for a boat that size.

 

[rickdb1boat]

Re: Merc Prop Selector

Depends on the boat and the prop. No 2 are alike. The prop selectors are just a guide to get you close... Sounds like you are right on with the prop you have now and going to a higher pitch would result in poor low end performance and possibly lugging the motor, which can lead to a short life.. That 23" pitch prop would drop your RPM's about 800 and that would put you way out of the recommended RPM range.. I agree with roscoe that you are in the zone... You're talking about pushing a 2000+ Lb load by the time you are loaded up, with a 75 HP. Is that speed figure with a normal load or just you? If with the load, you are right on..

 

[phatmanmike]

Re: Merc Prop Selector

my math says you should be able to go 44.7213mph with minimal gear and a perfectly flat day with no prop slippage......but......

 

[walleyehed]

Re: Merc Prop Selector

In my experience, the Merc prop selector has always shown recommendations for higher pitch than that which puts you in the correct rpm range.<br />On my boat, a 25" is recommended, and I can't even come close to the low end of my rpm range with a 25". I've found this to be true of most all applications I've compared, on many different set-ups.

 

[cobra 3.0]

Re: Merc Prop Selector

Just tried the Merc prop selector... it's totally full of cr_p! It recommends a 23 or 25 inch pitch prop for my boat for water sports...I use a 17" pitch and am in the correct rpm range.

 

[youngboater]

Re: Merc Prop Selector

Roscoe I also typed in the weight and I still get the same results? <br />Rickdb1boat That is with a normal load. About 2 people and 27 Gal. of gas (full tank). The 1500 is about all loaded up except add two guys so figure just under 2000lbs. and getting these speeds. It is a Lund Deep V with full flooring and all the goodies including an 8HP kicker. I know it isn't a very light boat. It's max HP is 90 and max persons is 6 or 975lbs so I know it is not underpowered at all or overloaded.<br />Walleyehead and Cobra 3.0 I totally agree with both of ya.