prop choice???

[kartman]

alright, i have a 16' glastron v-162 that is outfitted with a 79 merc 800. (80hp) im trying to find a prop that will give me good stern lift with a good holeshot, and better planing & speed holding under 20 mph. currently i have a standard 3 blade 13"-15p. the shop around me said they wouldnt put a smaller pitch prop on. the hard part is i dont have a speedo, or a tach. (putting those in while im rebuilding the powerhead) im just looking to get some other ideas as the shop around me is not the best shop imo. (the lead mech told me they dont make a 4blade in alum for any application!!!) any help helps. im new to boating (at least having my own boat) thanks!

 

[P 0 P E Y E]

Re: prop choice???

What size prop is on it now? How many rpms?

Are you sure you are running on all four?
With no tach and no clue, it's hard to find out what to do.

The Merc Dealer can suggest a prop and he is most likely to be spot on.

Need to know more info

 

[hwsiii]

Re: prop choice???

Kartman, your loaded boat with everything in my guess is about 1,900 pounds, and I find your motor to have a WOT recommended RPM to be between 4,800 and 5,200 RPM with your gear ratio at 2.3:1.if this is wrong please let me know as my calulations will be wrong. My program shows you should be running a 19" Pitch prop with that combination not the 15" and you should do about 33 MPH. That motor must have been worn out, everything ought to improve after you rebuild it. My numbers are listed below.

Boat and Motor

Prop Picker

Prop Change

H

 

[kartman]

Re: prop choice???

wow, that is awsome!! thanks for the insight. where did u find that? and for speed, my brother has a bayliner, and he paced me at 34mph with the 15p prop. but i think i was twistin that merc a little tight. we will see what i turn when i get the rebuilt motor on with a tach and speedo (aswell as a complete dash of gauges) thanks again!!!

 

[hwsiii]

Re: prop choice???

Kartman. that is a custom program I wrote to pick the correct prop for boats. And you were twisting it a little hard, and you are very welcome.

H