best prop pitch on jhonson 88 spol

[abner]

i have a jhonson 88 spl and i was wondering what pitch is best for this motor on a 16 foot bass boat i would like good hole shot also with good top end

 

[surrender]

Re: best prop pitch on jhonson 88 spol

Really need a place to start. How heavy is the boat? What have your tried so far? I run a 13 3/4 X 15 on my 17 McKee (1490 lbs dry) and get 34 mph at 5600 rpms. good hole shot. I wish the top end was more and have not checked fuel burn at various rpms. I run around 4800-5000 at 27-28 mph cruise. Seems high on the rpm side for cruise but I like to get where i'am going. These engines are not the most fuel efficient to begin with so i dont try to save a gallon an hour or so by dropping speed.

 

[Black as]

Re: best prop pitch on jhonson 88 spol

this link may help you http://www.castlemarine.co.uk/pitch.htm

 

[PaulsMarineSalvage]

Re: best prop pitch on jhonson 88 spol

You really need to have a starting point. What prop is on it now? What rpm do you turn at WOT????

I am pretty sure that motor isn't supposed to turn over 5500 rpm if you want to keep it in one piece so you need to see what rpm you are at now and then you can adjust.

As a general rule you can anticipate a 250 rpm change per inch of pitch if that helps. But there are other factors to consider like diameter, number of blades, etc......

 

[surrender]

Re: best prop pitch on jhonson 88 spol

5800 is the max rpm. We've been through that to death for my 88. I checked with many sources and all say 5800. I got mine to 5600 and i probably could have got to 5800 with some more trimming of the motor but the boat just porposises too much above 5600+. So I'am keeping what i got. May get some tabs to try to keep the bow down but motor trimmed out to see what i get.