Three to Four Question Again

[tompass]

I have a Solas 3 blade SS 15 1/4 X 17 prop on Honda BF225 with Key West 23 WA and turn 6200 rpm's with 2 people and 1/2 tank of gas. Top speed is about 48mph. With more than 2 people and/or with near full tank of gas, I seem to need a bit more stern lift and thus am considering a 4 blade SS prop. Question is should I drop pitch and/or diameter? What Solas prop or other prop would be recommended solution to gain stern lift and improve handling?

 

[rndn]

Re: Three to Four Question Again

4 blades will make a noticable difference in the stern lift category.

 

[tompass]

Re: Three to Four Question Again

I do understand that stern lift will improve but some are also saying that it comes at a cost of increased drag and some clunking going in and out of gear. Trying to decide on pitch and am considering a Honda 16 pitch 4 blade. I could even stay with a 17 pitch 4 blade as I will likely loose about 200 rpm's which would bring be down to an acceptional 6000 rpm's at WOT.

 

[rndn]

Re: Three to Four Question Again

It is not a definate that you will lose rpm's by going to an SS prop over an aluminum. SS doesn't flex as much but it also cuts through the water easier.

 

[tompass]

Re: Three to Four Question Again

I should have been clearer in original message. My Solas is a SS prop.

 

[jay_merrill]

Re: Three to Four Question Again

Many find that the extra blade will drop rpm by about 100 for the same pitch. Going from aluminum to SS may provide some changes too. I just went from a 3 blade Michigan Match 15" pitch to a 3 blade, cupped, SS PowerTech 15" and picked up 100 rpm.

Try to find a shop that will let you try a couple of used wheels before you buy. While there are some generally accepted rules of thump about prop changes, I think a bit of trial and error is valuable before plunking down 300 - 400 hundred bucks on a new prop.

 

[tompass]

Re: Three to Four Question Again

If all that would be lost going from cupped 3 blade SS to 4 blade SS is 100 rpm's, I would likely stay with 17P as I easily hit 6200rpm's with 3 blade. Still concerned with having heavier blade and affect on clutch dog shifting in and out.

 

[tompass]

Re: Three to Four Question Again

Has anyone used a Michigan Apollo SS 4 blade prop? There appears to be a great deal on a 4 blade 16 pitch SS on Iboats.