Stainless prop on 9.9 worth it??

[dainer]

Hi all-

Recently I was having trouble getting up to the recommended RPM's on my 2002 Mercury 9.9 4 stroke. I was getting 4400 rpms, with the factory 9x9 aluminum prop. I purchased a Solas Saturn 7 pitch to try to get me where I needed to be. Before installing the prop, I purchased a new carb. Now I am getting 5000 rpms with my wife and 5500 solo. 17mph and 23 mph. I am happy with these numbers since before I was topping out at 13. My question is, should I send my 7 pitch back and just continue to run the stock aluminum 9(It has a couple dings but nothing major) Or, should I send the 7 back and order a new stainless 9 pitch? Will I notice and speed gains with the stainless prop on the 9.9?????

 

[steelespike]

Re: Stainless prop on 9.9 worth it??

Is your speed by gps? Slip at 23 is really low,under 2 percent,not likely.
Either your tach is low or the speedo is optimistic.It does appear you can send the 7 back.
A ss change could net a few tenths to a few mph. Also perhaps better across the board performance.
You could improve your setup.
The anti vent plate (just above the prop) should be about even with or up to an inch above the bottom.
Eliminate or carefully distribute the weight.

 

[Texasmark]

Re: Stainless prop on 9.9 worth it??

What's your altitude? Some of the guys on here know what the ratio to hp reduction is. If you are at a higher altitude it could explain loss of performance. Usually the carb jets are changed to accommodate the thinner air to help to restore some HP.

Mark

 

[dainer]

Re: Stainless prop on 9.9 worth it??

I usually boat around 6,000 ft. I read that every thousand feet you lose 3%. So I bought a 15 hp carb instead of the 9.9 So far it runs like a champ. I am one of the lucky ones where that's the only difference...

 

[BF]

Re: Stainless prop on 9.9 worth it??

I think there is no point of having a SS prop on a small engine. The slight increase in efficiency of the SS prop is very small compared to how variable the load is that it's pushing. I think it'd be like the difference in your boat's performance if you had a full 5 gallon gas tank versus a 1/4 of a tank of fuel. Not enough to worry about. On the other hand, as you can see from your current aluminum prop, they ding relatively easily which protects your gears from damage. I'd return the 7" and buy a new aluminum prop (9 pitch), and keep your current one as a spare.

 

[Jlawsen]

Re: Stainless prop on 9.9 worth it??

I think there is no point of having a SS prop on a small engine. The slight increase in efficiency of the SS prop is very small compared to how variable the load is that it's pushing. I think it'd be like the difference in your boat's performance if you had a full 5 gallon gas tank versus a 1/4 of a tank of fuel. Not enough to worry about. On the other hand, as you can see from your current aluminum prop, they ding relatively easily which protects your gears from damage. I'd return the 7" and buy a new aluminum prop (9 pitch), and keep your current one as a spare.

Ditto, aint gonna change a thing but the thickness of your billfold.

 

[jestor68]

Re: Stainless prop on 9.9 worth it??

Hi all-

Recently I was having trouble getting up to the recommended RPM's on my 2002 Mercury 9.9 4 stroke. I was getting 4400 rpms, with the factory 9x9 aluminum prop. I purchased a Solas Saturn 7 pitch to try to get me where I needed to be. Before installing the prop, I purchased a new carb. Now I am getting 5000 rpms with my wife and 5500 solo. 17mph and 23 mph. I am happy with these numbers since before I was topping out at 13. My question is, should I send my 7 pitch back and just continue to run the stock aluminum 9(It has a couple dings but nothing major) Or, should I send the 7 back and order a new stainless 9 pitch? Will I notice and speed gains with the stainless prop on the 9.9?????

If you're happy with these numbers(I would be too), why would you want to go back to bad numbers?

:facepalm:

 

[dainer]

Re: Stainless prop on 9.9 worth it??

Ok guys, I sent the 7 pitch stainless back today. Will order a new 9 pitch aluminum and keep on trucking. I figured the stainless might be a little overkill for this engine. Thank you guys for the help!

 

[Texasmark]

Re: Stainless prop on 9.9 worth it??

Ditto, aint gonna change a thing but the thickness of your billfold.

+2.