2005 Sea Ray 200 Sport 5.0

[kawakx125]

non MPI motor, 1.62 alpha drive, stock aluminum prop. getting 4800 rpm and between 40 and 45mph. Would like to go to a stainless prop and try and get some more top end with good cruising performance and mileage. no major watersports with this boat, occasionally pull a tube but not much i don't think. I kinda figured this boat would run a little faster than it does.

 

[Maclin]

What pitch prop do you run now? Is the top speed attainable 45mph? Is it by GPS or speedo? Need the top speed and prop pitch to get any kind of recommendation or advice.

Having typed all that in, it appears from the numbers that you run a 19 pitch prop. Many times just going to stainless in the same pitch will do what you want, as there is more flex in aluminum props and you are right at the top of the recommended RPM range now.

Regarding top speed AND towing, how many passengers is a typical load? Have you towed a tube yet to see how it does now?

 

[floater212]

to get more speed out of it you would raise the pitch, if it's a 19" you would go to a 21" pitch but you may loose hole shot. But then aluminum flexes, so maybe the same size s/s. you can also go with a 4 blade combo which has 2 blades at one pitch and the other 2 blades at another, they say you get the hole shot and the top end, but I have not tried them. I use a 5 blade Ron Hill prop in a 19" pitch and I love it, they say their prop only have about 6% slip and the others have about 11% slip... big difference. go to mercury prop wizard to see the different prop and it may help you decide which way to go.

 

[kawakx125]

speedo, i believe it is 19p. I will double check. have not towed with it yet, usually theres 3-4 adults and a small kid or so. I will try and get gps speed next time were out. we've only had it out twice now, just picked it up on monday. was kinda disappointed with the top speed and cruise performance of it. i figured it would run 50+

 

[jkust]

45ish with a 19 sounds about right...40 sounds too low. I'd gps it just to verify as well as the pitot speedos tend to read high anyway at higher speeds. Mine is exact with the gps up to about 40ish then the speedo starts to read higher than actual. I think that 50+ (especially the plus) all day with a 3150lb boat with a full tank, a full crew and full of gear is asking a lot without the 270hp mpi v8. You'd be surprised what the difference with a 1/4 full tank and no crew is I'd bet.

 

[Scott Danforth]

my 2002 Searay 190 with the 220hp 5.0 1.62:1 drive turning a 15x19 Solas stainless prop would hit 50mph on the GPS. Best economy was at 3100 RPM with slight adjustment from trim tabs

your boat has a similar hull and weight, so you should be able to hit about 48

 

[kawakx125]

I was way off on the prop on it, i had assumed it was a factory prop being an aluminum one on there. looked closer today and it is a 4 blade 15'' x 16 pitch michigan wheel prop. the factory prop according to sea ray is supposed to be a 14.25'' x 21P Black max prop. i am assuming that given that, possibly a 4 blade in a 19P would get me close?

 

[Maclin]

Your top speed calcs to right at 40 with the 16p at 4800 rpm. Going to a 19p would get you between 47 and 48 at that same RPM (4800) in theory. That is if the engine can spin it up that high.

 

[kawakx125]

The diameter of the current prop is 15" whhich I assume is why the pitch is lower, correct?

 

[Maclin]

No, diameter is not related to pitch. Larger diameter is like a wider tire, can hook up in the water better. Pitch is how many inches one rotation of the piop will move hypotherically if there was no slip, like it was turning/cutting in styrofoam.

 

[kawakx125]

I suppose I will put a factory prop on it and see what that does for me. Lake conditions have been less than ideal for testing the few times I've had it out. My assumption is that the factory prop probably allows it to run max rpm or at least well within the range. Factory prop being a 3 blade 21p aluminum I have a hard time believing that a 16p aluminum 4 blade was the correct choice for cruising efficiency. It's very picky on trim and doesn't hold worth a crap. Theoretically I believe I should be able to run a 19p 4 blade stainless and stay within range, but that assumption is based on the factory propping it correctly. It's a gamble being once a prop hits the water you can't return it

 

[steelespike]

I have to wonder if the prop is on there because they wanted to keep their good one.Your description of the 4 blades performance is the opposite
of 4 blade performance improvements.
Should improve hole shot,stay on plane easier at reduced throttle,better grip, smoother, and respond better around the dock.
Sounds like a crap prop they just stuck on there.
Based on your rpm and speed its hard to think that a 19" ss 4b blade will reach the same rpm.
Usually suggesters to drop an inch going to ss because it will likely load the motor more than an al prop.

 

[kawakx125]

The factory aluminum is supposed to be a 21p 3 blade which is why I believe that a 19p 4 blade stainless would theoretically be close to the correct prop. It may very well over rev in calm water with the current prop

 

[kawakx125]

I put on a Solas HR4 17p after doing some more testing with the aluminum 4 blade that came with it. with the aluminum one i determined it was hitting the rev limiter while completely trimmed down and fully loaded, and only getting 37mph GPS speed. After putting on the SS solas, in choppy water yesterday with just the wife and 2 small kids i was getting 4400-4500 rpm @ 45mph. guess this will have to do, i'd like to get closer to 4800 but they don't make one in a 16p.

 

[steelespike]

Those numbers don't work 45 at 4500 1.62, 18"(suggested to increase test pitch 1") for performance prop) = 4% slip
Possible but unlikely. Could indicate rpm is actually higher. If we use 18" @ 12%(more typical) we get 4860.

 

[kawakx125]

I did some calculating after posting this and was getting the same results. i'm beginning to think my tach isn't accurate at higher rpms, which could potentially mean that this is the correct prop. do you happen to know what the rpm limiter is set at on the 5.0 TKS motors? if so then i'd have a rough idea of how far off my tach is. it was pretty close at idle in the driveway when i hooked up my handheld tach but i suppose i'll check it at full tilt next time were out. box said 17p, which is what i ordered, i'll double check the prop see if there are any numbers on it.

 

[kawakx125]

reading up a bit more the rpm limiter should kick in about 5k. with previous prop it was reading 4800 rpm and kicking in. assuming my tach is reading 200-300rpm low at full throttle, then this prop should be right around 4700 rpm or so. will definitely confirm this next time i can get out with a light load

 

[kawakx125]

My tach is definitely jumping around some, I can hit 4800 with this prop and a light load, usually we get about 4600 with 4 light adults, 2 kids, and a couple heavy coolers. Haven't GPS'd it at those numbers but the speedo reads about 45-47. Prop works well, but is pretty beat up now, caught the edge of a boat ramp when lake was very low once and bent the tips of a blade or two. Going to replace it soon, but I definitely think I should be able to turn an 18 or 19 pitch 4 blade prop based on what i'm reading others are running. Motor has 190hrs now, and I haven't done anything to it other than change the oil. Seems to run fine, but will bog and stutter the first time of the day when hammering it to get on plane. Going to do a full tune up and rebuild the carb before purchasing a new prop and see if there is any change. I have no idea if it has ever been tuned up, so it could just be that i'm a little down on power for one reason or another.

 

[Tail_Gunner]

Do yourself a favor down load a gps app on a smart phone if you have one, but most importantly get your tach accurate a 16 pitch on that boat is crazy, well kinda crazy. There is a quick fix however tiny tach, its fairly cheap well it was... 50 dollars now. That will allow you put on the 16 pitch and see your boat rpm at full WOT.
Maybe sound like a bit of a hassle, but a 16 pitch prop is way under propped your engine could be running badly if that boat does not pull like a tractor to 40 mph.

 

[kawakx125]

Currently its a 17P 4 blade stainless solas prop on there. OEM should have been a 21P 3 blade aluminum black max. I feel i should be able to turn at least an 18P 4 blade. The solas is fairly heavily cupped so its possible it may act more like a higher pitch. I have done the GPS thing, low-mid 40's but never did get great conditions for speed either.

I have a shop tach i will throw on the boat now and run it, checking it several times over a weekend. doesn't stretch all the way to the helm though which makes it difficult to use. Most of what i've posted has been just going off speedo and gauge on dash...not the most accurate but i can definitly assure you the boat isn't hitting rev limiter.