Prop Question

[bill-d-c]

Hi guys. I just bought a 1998 Marastar 225 Sport with the LT-1 engine. It has a 4 blade 14X18 prop (1 1/8") on it. The boat comes out of the hole very good, especially for a big boat, but I think engine RPM seems excessive at 40MPH (4800 RPM). I would rather sacrifice some out of the hole acceleration for a higher speed that doesn't tax the engine quite so much. I guess I have two questions:
What prop do you guys recommend?
Where is a good place to purchase one?
Thanks,
Bill

[AZX9]

I am like you in the way you think. You do however need to match the prop to the WOT specs. I'm not sure what an LT1 WOT range is but you should shoot for a prop that puts you on the lower end of your range at wide open throttle. Example 4600-5000 rpm choose a prop that would put you around 4600 rpm at WOT.

[Miss Rita]

FIrst, did you verify speed with GPS?

I'm guessing that if you went to a higher pitch prop your hole shot would suffer, your WOT RPM would be lower, and your top speed would be the same, or even slower.

I bet your recommended RPM range is 4400-4800, or perhaps even 4600-5000, so you probably have the correct prop.

If you want a fast boat then a direct drive is not the way to go.

[bill-d-c]

Originally Posted by Miss Rita

FIrst, did you verify speed with GPS?

I'm guessing that if you went to a higher pitch prop your hole shot would suffer, your WOT RPM would be lower, and your top speed would be the same, or even slower.

I bet your recommended RPM range is 4400-4800, or perhaps even 4600-5000, so you probably have the correct prop.

If you want a fast boat then a direct drive is not the way to go.

Didn't buy it because I thought it would be "fast". Just seemed to me that 4800 RPM is winding the motor pretty tight for only 40MPH. My 97 ProStar (LT-1), at 4800 RPM, was running 47 MPH with a four blade 14X20 prop. I rarely run my boats wide open, but this translates the same with lower speeds, (3000RPM to go only 20MPH). Maybe it's just this style boat. I've owned 6 Prostars, this is my first Maristar.
Bill

[toolz]

I have a '98 MariStar 200VRS, came with a 14x18 and a 14x20. I like the 20 a lot better. My boat's a bit smaller than yours, but it comes out of the hole very strong, and the LT1 turns about 5000 rpm at 50 mph. Just got my boat back from the dealer after replacing the strut, shaft and prop from hitting a rock in a low lake. It has a bright shiney OJ 14x20 that I would really like to try out, but due to the drought, there's no safe water around here.

[bill-d-c]

Originally Posted by toolz

I have a '98 MariStar 200VRS, came with a 14x18 and a 14x20. I like the 20 a lot better. My boat's a bit smaller than yours, but it comes out of the hole very strong, and the LT1 turns about 5000 rpm at 50 mph. Just got my boat back from the dealer after replacing the strut, shaft and prop from hitting a rock in a low lake. It has a bright shiney OJ 14x20 that I would really like to try out, but due to the drought, there's no safe water around here.

Now that sounds much more in line with how I believe the RPM and speed should line up. Most boats that I've owned have had that ratio, or close to it, ex: 3000RPM = 30MPH, 4000RPM = 40 MPH, ect. I always like to carry a spare prop, I will look at getting a 14 X 20 to replace the 14 X 18. I know this is a heavy boat and honestly 40 MPH for a top speed isn't completly disgraceful. It just shouldn't take close to 5000 RPM to push it that fast, IMO.
Thanks for the info,
Bill

[petermegan]

I had a 14*18 on my prostar with slot and ordered a 14*20 from ACME (can't remember the number) but it was overpropped and could only get 4300rpm with an LTR. Might need to get some good advice from OJ or ACME before you spend the money. I am like you in that I was chasing 40mph at 4000 etc.

[bill-d-c]

Originally Posted by petermegan

I had a 14*18 on my prostar with slot and ordered a 14*20 from ACME (can't remember the number) but it was overpropped and could only get 4300rpm with an LTR. Might need to get some good advice from OJ or ACME before you spend the money. I am like you in that I was chasing 40mph at 4000 etc.

When I bought a spare prop for my 97 Prostar (LT-1), I bought a 14 X 20. I think it too had a 14 X 18 from the factory. Anyway, it didn't overprop it. Helped with lowering RPM's and to be honest, I couldn't tell any difference in out of the hole performance. I bought that prop from my locat MasterCraft dealer, I take it OJ is a prop manufacturer? I will look online tomorrow, see what I can find out.
Thanks for your input,
Bill

[maristardd]

I happened to be looking at the Maristar manual online for my 94 225:

94-97 Maristar LT1 (225/225VRS)
WOT max allowable RPM :5000
Top Speed: 47 MPH
(13x13 prop on 1:1, 14x18 on 1:5)

... I thought powerslot would only drop top speed one or two MPH, maybe some other reason you are not going faster? The weight of the 98 225 is 3350 (NADA), vs 3000 pounds of the earlier ones I've listed above.

FWIW, the LT1 is worth 4 mph top speed gain over standard 350 94-97, so maybe there is a horsepower/tune issue at play as well?

[bill-d-c]

Originally Posted by maristardd

I happened to be looking at the Maristar manual online for my 94 225:

94-97 Maristar LT1 (225/225VRS)
WOT max allowable RPM :5000
Top Speed: 47 MPH
(13x13 prop on 1:1, 14x18 on 1:5)

... I thought powerslot would only drop top speed one or two MPH, maybe some other reason you are not going faster? The weight of the 98 225 is 3350 (NADA), vs 3000 pounds of the earlier ones I've listed above.

FWIW, the LT1 is worth 4 mph top speed gain over standard 350 94-97, so maybe there is a horsepower/tune issue at play as well?

I don't think that's it because the engine will hit 5000 RPM, and get there pretty quick as well. It's just not pushing the boat much past 40 MPH. I think it's part prop, and possibly the speedo needs re-calibrated, I don't know for sure, just doesn,t seem right to me. These boats aren,t speed boats, I know that. I just didn,t expect cruising speed to be 30-35 MPH with WOT to be 40.
Bill