More Speed What's Left?

[Smoky Mountain]

At 25 hours and after all the fluids were changed:

Did a couple WOT run. 5400 RPM said the tach max, 34.5 MPH said the GPS. 98 percent clean toons. Two persons, 25 gallons fuel, 82F, 800 ft elevation, about a 2 mph wind, almost no waves or chop.

Tops down. Fiddled with trim.

Mechanic said it should run 5600-5800. Dealer thought it would turn 38. It might under optimal conditions and lighter load.

15.25 x 15 wheel.

How much speed is left and how much will It cost to eek out the last 2-3 mph?

I'm assuming my towing/hole shot and low end torque may suffer to get the top speed.

I'm plenty satisfied the way it is now assuming with 6 persons on board I can tow a two person tube and get 25 mph which I think I will be able to.

2012 2274GL with Yamaha 150LTR.

Options:

Power Assist/Hydro Steering

33 Gallon Tank

Double Bimini

Dual Battery w/switch

Express Performance Package (3 25inch tubes and wave shield)

Extended Swim Deck 18inches

 

[Fyrfightr]

According to the prop slip calculator your at 10% slip. That's good....

 

[Bigtop]

All I can do is give you my experience with getting my boat proped right for my typical load which is 6 to 8 adults and several kids. I have a 2275rli with ESP and 150 Yamaha. Started out with a 4 blade 15.25x15 prop which was great for top end speed of 39 at 5600 with only two on board. But with my typical boat load of several people, it would only run 30 to 31 at 4900 to 5000.

After trying several props, I ended up with a Power Tech 15x13 4 blade that they have designed for pontoons. I love the prop in that it has really increased my performance with a load and has increased my turning radius considerably. It now runs 36 to 37mph with two on board while at 6200 rpm's. But with a load of people and pulling skiers, it will run 32 mph at 5600 rpm.

I guess the bottom line is you need a prop for your typical load. I can always back out of the throttle if need be with a light load but I can't get extra power when needed with a high speed prop. Yea, I guess it's pretty cool to have the high speed to show off a little, but that's not what I need with my typical boating practices.

Power Tech offers a great program for trying props. You can call or email them with what you currently have and what your wanting from your boat. They will suggest the right prop. After you purchase the prop, if your not happy with it you can exchange it within 30 days for a simple restocking fee, which I think is only $30. You can continue to exchange until you find the prop you want but I really don't think that will happen often as these guys are pretty good at getting the right prop the first time.

Well after all that said, I think you should go down to a 14 or a 13 pitch to get your rpm's up as close to 6000 as possible. You might get the top speed very one likes to brag about, but you'll have the performance in the lower end your looking for.

Might two cents

Hope it helps

 

[Smoky Mountain]

All I can do is give you my experience with getting my boat proped right for my typical load which is 6 to 8 adults and several kids. I have a 2275rli with ESP and 150 Yamaha. Started out with a 4 blade 15.25x15 prop which was great for top end speed of 39 at 5600 with only two on board. But with my typical boat load of several people, it would only run 30 to 31 at 4900 to 5000.

After trying several props, I ended up with a Power Tech 15x13 4 blade that they have designed for pontoons. I love the prop in that it has really increased my performance with a load and has increased my turning radius considerably. It now runs 36 to 37mph with two on board while at 6200 rpm's. But with a load of people and pulling skiers, it will run 32 mph at 5600 rpm.

I guess the bottom line is you need a prop for your typical load. I can always back out of the throttle if need be with a light load but I can't get extra power when needed with a high speed prop. Yea, I guess it's pretty cool to have the high speed to show off a little, but that's not what I need with my typical boating practices.

Power Tech offers a great program for trying props. You can call or email them with what you currently have and what your wanting from your boat. They will suggest the right prop. After you purchase the prop, if your not happy with it you can exchange it within 30 days for a simple restocking fee, which I think is only $30. You can continue to exchange until you find the prop you want but I really don't think that will happen often as these guys are pretty good at getting the right prop the first time.

Well after all that said, I think you should go down to a 14 or a 13 pitch to get your rpm's up as close to 6000 as possible. You might get the top speed very one likes to brag about, but you'll have the performance in the lower end your looking for.

Might two cents

Hope it helps

Big top having essentially the same engine and configuration I wonder why I don't get over 5400 rpm?

I don't think I would pu 3-4 mph with an added 200 rpm.

How do I get to 5800? 5600- 5800 is supposedly the max and the 15.25 x 15 optimal?

 

[Bigtop]

One thing that is unknown in your boat description is whether or not you have lifting strakes on any tubes or not. Also different brand or style of props will offer different characteristics depending not only pitch, but also rake and cupping. I was always told to get the most "all around" performance was to get as high as you can in the WOT rpm range. The Yamaha 150 is 5000 to 6000. I prefer to stay in the upper end to keep from lugging the engine.

I would say however that if your boat has no strakes at all, your probably at your peak. But if you change to a lower pitch, you will have better performance with a load of people.

Remember, prop selection is not a science, it's trial and error.

 

[Smoky Mountain]

One thing that is unknown in your boat description is whether or not you have lifting strakes on any tubes or not. Also different brand or style of props will offer different characteristics depending not only pitch, but also rake and cupping. I was always told to get the most "all around" performance was to get as high as you can in the WOT rpm range. The Yamaha 150 is 5000 to 6000. I prefer to stay in the upper end to keep from lugging the engine.

I would say however that if your boat has no strakes at all, your probably at your peak. But if you change to a lower pitch, you will have better performance with a load of people.

Remember, prop selection is not a science, it's trial and error.

Strakes on center tube only.

 

[Bigtop]

It sounds lIke you haven't had boat for long since your just getting it broke in. I would contact your dealer and see if he will work with you on prop selection. My dealer did with me using Power Tech props. I think a good dealer would be willing to get you where you want to be. I'm afraid when you load your boat with 6 adults and try and pull a tube, your not going be in your rpm or mph range. If you are to low in the rpm range, you will lug your engine which is not good. A good rule of thumb is to get your rpm right up to the rev limiter which is 6200 rpm's with a light load, then you will have the rpm's needed with a full load. Best of luck as it can be a little frustrating but can take a few changes before you get it right. But you will be glad you did as you will know your boat is performing at its best.

 

[Smoky Mountain]

It sounds lIke you haven't had boat for long since your just getting it broke in. I would contact your dealer and see if he will work with you on prop selection. My dealer did with me using Power Tech props. I think a good dealer would be willing to get you where you want to be. I'm afraid when you load your boat with 6 adults and try and pull a tube, your not going be in your rpm or mph range. If you are to low in the rpm range, you will lug your engine which is not good. A good rule of thumb is to get your rpm right up to the rev limiter which is 6200 rpm's with a light load, then you will have the rpm's needed with a full load. Best of luck as it can be a little frustrating but can take a few changes before you get it right. But you will be glad you did as you will know your boat is performing at its best.

Sounds like I need to try a 14.5 x 15 stainless.

 

[Bigtop]

I personally don't think that will get you there. Your basically needing 4 to 600 rpms to get you to your 6000 WOT. Keep in mind, the more you load the boat, the more your rpm's will drop. On average, you will gain 200 rpm's with each pitch drop. The diameter will help also, but the 3/4 of a inch your dropping will not get probably more than 100 rpm's.

Again I am no expert, but if it were my boat, I would try a 14.5 x 14 or a 15x13

 

[Smoky Mountain]

I personally don't think that will get you there. Your basically needing 4 to 600 rpms to get you to your 6000 WOT. Keep in mind, the more you load the boat, the more your rpm's will drop. On average, you will gain 200 rpm's with each pitch drop. The diameter will help also, but the 3/4 of a inch your dropping will not get probably more than 100 rpm's.

Again I am no expert, but if it were my boat, I would try a 14.5 x 14 or a 15x13

Thanks for the suggestions. I'm not that interested in increased speed (at the top) but I don't want to unduly "lug" and I would also like to maximize fuel economy.