1998 75 HP Force prop replacement

[dt4ever]

It's time to replace the beaten up original alum prop on my 98 75hp Force. When it comes to prop I'm totally a newbie. Currently my bass boat top out close to 40mph with 1 person at appox 5800-5900 rpm. I think it's a bit high. The prop is 10x14. Should I go for a higher pitch SS prop with a larger diameter to reduce the rpm at WOT? A quick search on iBoats resulted from 10-12x15 SS prop.

Any input is greatly appriciated.

Thank you.

 

[jestor68]

Re: 1998 75 HP Force prop replacement

I'd say that you need to go up to a 16" to reduce your rpm to around 5400 rpm.

 

[dt4ever]

Re: 1998 75 HP Force prop replacement

Thank you for responding Jestor. So I should try at least 16 pitch on alum which equal to 15 in a SS prop to achieve lower rpm right? Do you recommend any particular brand for SS? Also will a 4 blade yield a better performance?

 

[Frank Acampora]

Re: 1998 75 HP Force prop replacement



No --wrong-- Stainless props of the same brand, model, and size generally run about 200 RPM FASTER than aluminum. Go up to a 16 pitch stainless prop which will be cupped and your RPM will drop about 400. That is, if you want to spend the extra money for stainless, otherwise go for 16 pitch aluminum. Personally, I run only stainless and use aluminum for emergency props.

If they make one for your engine, I really like Ballistic stainless. However, because of the aggressive cupping, larger blade area and aggressive rake they tend to drop RPM more than stock type props. You may need the same pitch you have now.

If interested, search my past post comparing the Ballistic to other props on an early model Force engine

 

[jestor68]

Re: 1998 75 HP Force prop replacement

I assume you are looking at the Turning Point Express SS prop in 10.5 X 15. That prop should work fine for you. The Mercury Silverado 15" would also work fine(a little cheaper).

 

[dt4ever]

Re: 1998 75 HP Force prop replacement

After reading through everyone advice and Iboats prop tip section, 15 pitch SS sounds like a winner. There are few brands that I like but not sure which one will be the best price/performance wise for such engine.

10-1/8 x 15 Apollo 3-Blade (993408) 194.93
10-1/8 x 15 RH Michigan Wheel Ballistic Stainless Propeller (395130) for $294.99
Mercury Silverado $296.99
Turning Point Express Stainless #3130 $313.14

Is there a huge difference in performance between the Apollo and the rest?

Thank you.

 

[emoney]

Re: 1998 75 HP Force prop replacement

Wow, that's quite a price difference. Never seen a SS prop for under $200.00 I may have to check them out myself.

**edit** That Apollo is a Michigan Wheel prop from what I just googled and I've heard good things about Michigan Wheel anyway.

 

[jestor68]

Re: 1998 75 HP Force prop replacement

After reading through everyone advice and Iboats prop tip section, 15 pitch SS sounds like a winner. There are few brands that I like but not sure which one will be the best price/performance wise for such engine.

10-1/8 x 15 Apollo 3-Blade (993408) 194.93
10-1/8 x 15 RH Michigan Wheel Ballistic Stainless Propeller (395130) for $294.99
Mercury Silverado $296.99
Turning Point Express Stainless #3130 $313.14

Is there a huge difference in performance between the Apollo and the rest?

Thank you.

Are you certain you're looking at the correct page for a 1996-1998 Force 75? I don't see the Michigan stuff on the page I'm looking at.

 

[dt4ever]

Re: 1998 75 HP Force prop replacement

Jester, the Michigan Apollo and Ballistic are available from different supplier, iboats store does not carry them. Question though, do I need a new hub if I go with SS prop or the old one will do just fine?

Thank you.

 

[jestor68]

Re: 1998 75 HP Force prop replacement

Jester, the Michigan Apollo and Ballistic are available from different supplier, iboats store does not carry them. Question though, do I need a new hub if I go with SS prop or the old one will do just fine?

Thank you.

What brand of prop are you replacing? Merc and Mich generally use the same thrust washer. Solas likes their own. Not sure about Turning Point.