Prop Help for 22 ft tritoon with 150 Honda???

[duganderson]

I bought a used 2007 22 ft tritoon with 25 inch tubes. It has a 2007 Honda 150 4-stroke. The boat and motor supposedly weigh about 2500--3000 lbs. We tend to like to waterski and generally have 4-10 people on the boat (adults and teens). We have tried a few different props and I'm very confused about what is the best prop for us. Here is the data we have for all three all aluminum props we have tried. The out of the hole performance is pretty good and pretty similar with all three props......

-4 people in boat with 15.25 x 15 3-blade prop got max 26.5 mph at 4,950 rpm (this prop is somewhat beat up with some small chunks missing and small bends on the end of the prop.

-7.5 people (7 adults and 1 child) in boat with 15 x 17 3-blade prop got max 24 mph at 5,900 rpm.

-4 people with 15? x 17? 4-blade prop was approximately 26 mph? at 4,700? These numbers are from memory so I'm uncertain and we don't have this prop anymore

What prop would you recommend for us?

Would you recommend a 3 or 4 blade prop and why?

What should we shoot for for the max rpm on this motor? When we were running at 5900 rpm with the 2nd prop listed, we got the overheat light and some smoke from the engine; however, the intake was pretty covered with algae. We cleaned it but have not tried it since.

Thanks, Doug

 

[ihearth2o]

What prop would you recommend for us?

The one that gets you to the high end of the engine manufacturer's recommended WOT RPM range.

 

[duganderson]

The one that gets you to the high end of the engine manufacturer's recommended WOT RPM range.

It looks like the WOT RPM range is 5000-6000. Should I shoot for 5500 which is what the 150 hp was rated at?

If the 15 x 17 is running at 5900 with 7-8 people on it, I'm feeling like I'm too close to the top RPM. Would you recommend increasing the prop size or increasing the pitch or a little of both? Which would increase top speed more?

 

[steelespike]

I think you have a performance issue. Being a tri toon it should perform close to a runabout.
Some typical numbers Bennington 3300lbs. 17" prop 5800 @ 38.7,Bennington 2200 lbs 15" 6400 @ 37.9
Premier 2200lb 15" 6300 @ 32.7 It's clear your under performing.All these boats were running ss 3 bld. props.
The right aluminum prop should perform in the ball park. with a similar pitch.
Your tests with 4 aboard should be in the ball park with these tests.
We need a lightly loaded test to be able to evaluate your setup.
Are the tubes clean and smooth?
Is the motor in excellent tune?

 

[duganderson]

We bought the boat used so I don't know if it has had a tune up recently. I'm guessing, however, that it is not a motor problem since we are in the correct RPM range with the 15x17 prop. Does that sound correct to you too?

The tubes were pretty clean but maybe there is some buildup on them now because our lake gets very green from algae.

I got an e-mail from the manufacture of the boat and they recommended a 15.5 x 13 prop. Prop # 58130-ZY3-013A This prop, however, would seem to go slower unless the bigger diameter would help with the speed. What are your thoughts?

One question......on the numbers quoted below, are those size or pitch? I'm assuming they are pitch.....if so, what is the size of those props?

Thank you, Doug

I think you have a performance issue. Being a tri toon it should perform close to a runabout.
Some typical numbers Bennington 3300lbs. 17" prop 5800 @ 38.7,Bennington 2200 lbs 15" 6400 @ 37.9
Premier 2200lb 15" 6300 @ 32.7 It's clear your under performing.All these boats were running ss 3 bld. props.
The right aluminum prop should perform in the ball park. with a similar pitch.
Your tests with 4 aboard should be in the ball park with these tests.
We need a lightly loaded test to be able to evaluate your setup.
Are the tubes clean and smooth?
Is the motor in excellent tune?

 

[steelespike]

I think your rpm with 7 people aboard was mostly slip.Your speed was less than the 15 (26) the 17 was 24.
The 15 at 4950, 26.5 mph has a slip of about 18%The 17" at 5900 24 mph is 45%.
Its possible the big load disturbed the water too much.
18% slip is very good for a pontoon even a tritoon,especially at the reduced rpm.
I think when they suggested a 13" they were thinking of only the too low rpm.
​ I think from the tests I quoted it's easy to see a 15 should produce more rpm.
The Premier test with a 15" prop at 6300 rpm has a reasonable 21%slip and 32.7 mph.
Before messing with more props you need to be sure the motor is right and the tubes are clean.
Your prop demension 15" is the distance the prop moves forward in one revolution.
The slip expresses the actual distance through the water (a liquid).
Slip is usually double digits some where around 10 to 15% pontoons, cruisers and houseboats have higher slips.

 

[duganderson]

Thank you for the additional feedback and details. Is the slip possibly due to a prop that is too small. The boat manufacturer recommends a 15.5 " prop. Would a bigger prop likely help?

I will check out the motor and tubes too.

--Doug

I think your rpm with 7 people aboard was mostly slip.Your speed was less than the 15 (26) the 17 was 24.
The 15 at 4950, 26.5 mph has a slip of about 18%The 17" at 5900 24 mph is 45%.
Its possible the big load disturbed the water too much.
18% slip is very good for a pontoon even a tritoon,especially at the reduced rpm.
I think when they suggested a 13" they were thinking of only the too low rpm.
​ I think from the tests I quoted it's easy to see a 15 should produce more rpm.
The Premier test with a 15" prop at 6300 rpm has a reasonable 21%slip and 32.7 mph.
Before messing with more props you need to be sure the motor is right and the tubes are clean.
Your prop demension 15" is the distance the prop moves forward in one revolution.
The slip expresses the actual distance through the water (a liquid).
Slip is usually double digits some where around 10 to 15% pontoons, cruisers and houseboats have higher slips.

 

[steelespike]

A prop with a good full diameter should do well. Look for 4 blade pontoon specific props.

 

[duganderson]

A prop with a good full diameter should do well. Look for 4 blade pontoon specific props.

What do you mean by good full diameter? How big?

 

[steelespike]

Props up to 16" diameter will fit.I think you will find that a pontoon dedicated prop will have large full blades and good diameter.
You may also observe that as pitch goes down diameter goes up. and vice versa.