Prop for 185 Sport 3.0L

[Water Boy]

I just got a 2007 185 sport with a 3.0L in it. I've wanted one of these little boats for a few years now but hard to come by in my area (no dealer around) I found a good deal on one a couple of weeks ago but it was 600 miles away and had a 3.0L in it (I really wanted a v6) anyways, long story short, the boat only had 100 hours on it and well loved and I got it for a great price so I took two days off from work and drove down to get it.

First ride out went really well. Not unhappy with the little 3.0L. Mostly always going to be my wife and two kids in the boat. I hit 38mph (gps) @ 4500 rpm with all aboard and a full tank of fuel. Original 14.5 x 19 prop on it.

Now my question. Buddy that I bought it from gave me two other props. A 14 x 19 SS he said came on boat when he bought it but was worried about hitting something so he took it off and he through in a 14.25 x 21 he had from a previous bought. Any advice on what I should use? I could swap them out and try them all to compare but if there isn't any point I won't bother. Ill either sell them or keep as spares.

Ive read a bunch of posts but not much info about the 3.0L. Any advice would be great. Thanks

 

[Lazy Daze]

I wouldn't bother with either of those other props. The 3.0L doesn't really have enough torque to take full advantage of the SS. The 21" is too big so you're going to lose RPM's and you're already at the lower end of your proper range. Honestly, the prop that is on it seems to be doing just fine.

What would be the reasoning for wanting to change props - is there something you want the boat to do that it's not?

 

[Water Boy]

No real reason other than I already have them and know that a lot of people upgrade to SS props. I really haven't had the boat out enough to know. Seems to get up plane okay, I did think it would go a little faster and get to about 4800rpm but like I mentioned, I'm not disappointed with her. I guess my thinking is that if I'm sitting on a better prop than the stock one I would definitely use it, if not oh well I'll leave it alone.

 

[Lazy Daze]

Sea Ray designed that hull with the way 'most' people will use a boat like this... Watersports and cruising around. If you noticed, there is very little bow rise with that boat and you really don't even need a whole lot of throttle to get up on plane. They could make it faster, but it would sacrifice the quick-to-plane nature of it. I remember when that boat was first introduced - it was about 400lbs (the equivalent of two big guys) heavier than the boat it replaced and used the same engine. Honestly, I was a little worried. I immediately took the first one we got in to the water. Took another guy with us and even grabbed some guy off the shore to go for a boat ride (he said he was about 300lbs). To my (happy) surprise, it got onto plane faster than the boat it replaced. It really is a nice hull design.

With just you and light fuel, you should get into the low 40's. Weight has a big impact on boats and the smaller the boat, the more effect it has. It only takes a few minutes to change a prop - since you got them, try it out. If nothing else, it's good experience.

 

[Water Boy]

Thanks for the advice. If I can get an afternoon alone with it I might just try the SS prop and see. I did notice it was quite a bit heavier than the aluminum one so not sure if that will cancel out any potential benefit on a lower hp motor. I'd like to see 40 mph out of her but wouldn't want it at the expense of the decent hole shot it currently has. I really like the way this boat gets on plane. I noticed right away that it didn't take any effort, even the times I did a real slow acceleration, it still just seemed to glide up on top of the water and stay there at low speeds. Not really sure yet why I've heard so many people say they felt they had to install smart tabs.

I figured the 21 pitch would be too much for it so I'll just try the SS one and see how it works.

 

[Docsteder]

I have a 08 like yours. Current top speed is 37 mph checked with GPS at 3700 RPMs. I'm currently running the prop that came with the boat, a 14-1/2"
19 pitch Quicksilver aluminum. They say SS doesn't flex like aluminum and will give you a better hole shot and acceleration. I've put just over 50 hours on it in this first year and will be upgrading to a SS in the future.
That's after I find out why my WOT is so lo. Good luck.


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[Lazy Daze]

Thanks for the advice. If I can get an afternoon alone with it I might just try the SS prop and see. I did notice it was quite a bit heavier than the aluminum one so not sure if that will cancel out any potential benefit on a lower hp motor. I'd like to see 40 mph out of her but wouldn't want it at the expense of the decent hole shot it currently has. I really like the way this boat gets on plane. I noticed right away that it didn't take any effort, even the times I did a real slow acceleration, it still just seemed to glide up on top of the water and stay there at low speeds. Not really sure yet why I've heard so many people say they felt they had to install smart tabs.

I figured the 21 pitch would be too much for it so I'll just try the SS one and see how it works.

I know for a fact you'll get into the low 40's - I've been on that many, many times. It all comes down to how much weight is in it. You'll notice a difference when it's just you in the boat.

 

[blaster]

I have a 08 like yours. Current top speed is 37 mph checked with GPS at 3700 RPMs. I'm currently running the prop that came with the boat, a 14-1/2"
19 pitch Quicksilver aluminum. They say SS doesn't flex like aluminum and will give you a better hole shot and acceleration. I've put just over 50 hours on it in this first year and will be upgrading to a SS in the future.
That's after I find out why my WOT is so lo. Good luck.


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Your numbers add up to negative slip of -.11157
Sounds like your tachometer is off. Check the tach for loose wires, bad ground, etc.

 

[Water Boy]

Lazy Daze: I think I should probably take her out again by myself so I'm comparing apples to apples before I try it with the SS prop. I read a bunch about a SS props possibly causing damage to drive units if they strike anything but I'm not too concerned about that. I know my area pretty well and I've always got an eye on my depth finder.

Docsteder: The numbers you posted for your boat don't add up to me?? 37mph @ 3700rpm? My engine at that speed is turning about 4500pm. At 3700rpm I'm doing about 30-32mph. I would imagine that if there was something robbing your engine of enough power to keep it from reaching maximum revolutons you wouldn't be able to reach 37mph. Blaster is right, I would be questioning the accuracy of your tach.

 

[Docsteder]

Lazy Daze: I think I should probably take her out again by myself so I'm comparing apples to apples before I try it with the SS prop. I read a bunch about a SS props possibly causing damage to drive units if they strike anything but I'm not too concerned about that. I know my area pretty well and I've always got an eye on my depth finder.

Docsteder: The numbers you posted for your boat don't add up to me?? 37mph @ 3700rpm? My engine at that speed is turning about 4500pm. At 3700rpm I'm doing about 30-32mph. I would imagine that if there was something robbing your engine of enough power to keep it from reaching maximum revolutons you wouldn't be able to reach 37mph. Blaster is right, I would be questioning the accuracy of your tach.

Yeh, I was thinking that as well. However; when I disable the out drive and just rev the engine I'm getting way over max WOT.

Just got off the phone with the steeler service department and he's suggesting to check plugs, cap and rotor and a compression check. He's also looking the last owners history for me. According to him, not to far off. FYI;
I just hit 100 hours my last time out.


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[Water Boy]

Yeh, I was thinking that as well. However; when I disable the out drive and just rev the engine I'm getting way over max WOT.

Just got off the phone with the steeler service department and he's suggesting to check plugs, cap and rotor and a compression check. He's also looking the last owners history for me. According to him, not to far off. FYI;
I just hit 100 hours my last time out.


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It's only got 100 hours on it so I wouldn't go throwing too many parts at it although the tune up parts are always a good investment. I would really want to ensure that the engine is in fact only reving to 3700rpm because you are actually getting near the top speed for this boat. If anything, I would suspect the carburetor to be dirty from sitting so much or not being stored properly. Mine has 100 hours on it and had sat for a year before I got it. Ran like a bag of crap when I first started using it. If the main jet was restricted you wouldn't reach max revs under load but it would rev up in neutral. With that being said I still wouldn't expect it to reach 37mph with any kind of power issue.

 

[dutchman]

Docsteder.........3700 rpm is 3700......regardless if its running on 2 cylinders or 4. If you truly are going 37 mph, then your tach is reading incorrectly.

Back to the thread.....Waterboy....I have a 175 with the same 3.0L, prop 14.5 x 19 alum. Weight is definitely a factor on mine. With 2 people (total 350 #'s) I hit 4800 rpm and 42 mph. As the weight increases, the rpm goes down a bit. Overall it works great.
I tried a SS H5, got the same WOT rpm, but did not improve the bottom end or the entire range. Sounds like the 3L doesn't have the torque to turn the H5. The alum works the best for me.
For sure try that SS 14x19

 

[Water Boy]

When I get a chance I'm going to try and do a real comparison between the two under different conditions. It makes sense to me why there wouldn't be much difference in performance between the two under light to moderate load because there wouldn't be much flexing of the aluminum prop causing it to loose thrust but what about under heavy load such as pulling a skier or having a boat load of people aboard. I'm thinking there probably would never be much change to the top speed but the SS prop might be better able to get up on plane under load. I will post my findings once I've had a chance to run through a few different scenarios. Might not find anything significant but it will be fun trying it out.

 

[Water Boy]

So I had my boat out for a ride today and made note of some #'s still running my oem alum. prop. I'll post them and this weekend switch over to the ss prop. Next time I'm out ill record the numbers under the same conditions.

So with 3/4 tank of fuel, my wife and 2 toddlers, heading in to the wind with about 1 foot waves and my drive trimmed out pretty efficient this is what I got. I used one of the online slip calculators to do the math.

Gps Tac. Slip Theoretical speed
20mph = 3000rpm 26% 27mph
25mph = 3400rpm 19% 31mph
27mph = 3600rpm 16% 32mph
30mph = 3800rpm 12% 34mph
38mph = 4500rpm 5% 40mph

It seems to be pretty efficient at wot but I was surprised at how much slip there was at cruising speed.