Best prop for idling/no wake boating?

jcr159

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Hey everyone, new here... New owner.

Just purchased a 24 LSB tritoon with sps+ package, and a yamaha 250 vmax sho. (don't ask, way more motor than i wanted... keep reading...)

My lake is primarily no wake. There is about 10% that allows "speed zone" activities like tubing/skiing that we will use for teenager tubing mostly.

Outside of that, I could give a rat's patootie about top speed. See above for why...

Knowing that I'm mostly idling around, and need low speed maneuverability, and some watersports fun (probably while loaded with 8 adult total... some in the water on the tube, lol)... what should i be looking at prop wise? I'm guessing this is a good time to look at a 4 bladed prop. are there brands/model lines i should focus on? I know pitch/diameter will come down to water tests at WOT, but am i wrong to think this is the situation to default to 4 blade?

I can't find a lot of info from folks on what they run when most/all usage is at no wake speeds.

thanks for any help!
 
i just replaced my stainless Yamaha 3 blade 14x13 (lot smaller motor then yours, 115hp Vmax) with a Turning Point 13.5x15 4 blade aluminum becasue i was running max rpm. I dropped 200 rpms with the new prop. It pops out of the water faster and more maneuverable. It has more bite but I lost 2 mph. I might buy a 13.5x17 4 blade to try to get the speed back. They are only $95 for a prop and should drop 200 more RPMS. I should be around 5800 rpms then.

I say look at your current prop, go up one size in 4-blade and being a 250hp, stay with stainless. Every prop mfg has a prop selector to help
 
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i just replaced my stainless Yamaha 3 blade 14x13 (lot smaller motor then yours, 115hp Vmax) with a Turning Point 13.5x15 4 blade aluminum becasue i was running max rpm. I dropped 200 rpms with the new prop. It pops out of the water faster and more maneuverable. It has more bite but I lost 2 mph. I might buy a 13.5x17 4 blade to try to get the speed back. They are only $95 for a prop and should drop 200 more RPMS. I should be around 5800 rpms then.

I say look at your current prop, go up one size in 4-blade and being a 250hp, stay with stainless. Every prop mfg has a prop selector to help

Thanks! always good to hear other's experiences. I'm curious that you are thinking to go up in pitch even more... most advice i've seen is that switching from 3 -> 4 blades you should drop pitch. you've done the opposite, but you also dropped half and inch in diameter... I'd be curious what a 13.5x13 4 blade would net you actually...
 
Thanks! always good to hear other's experiences. I'm curious that you are thinking to go up in pitch even more... most advice i've seen is that switching from 3 -> 4 blades you should drop pitch. you've done the opposite, but you also dropped half and inch in diameter... I'd be curious what a 13.5x13 4 blade would net you actually...
With the original prop, i was at max RPM for my motor (6.3k). If you go up a pitch, you lose 200-300 rpms. I am at 6k now by going up. If it was running 6k prior, i would of stayed the same pitch.

Turning Point props are cheap and they have a great return policy for "pitch exchange" program . The prop's i am playing with are only $90, cheaper then a night out.

I heard with a Mercury Nemisis prop, you need to drop a pitch. I dont know about Solas props.

Don't forget to order a hub kit for your new prop if you switch from a Yamaha prop.
 
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With the original prop, i was at max RPM for my motor (6.3k). If you go up a pitch, you lose 200-300 rpms. I am at 6k now by going up. If it was running 6k prior, i would of stayed the same pitch.

Turning Point props are cheap and they have a great return policy for "pitch exchange" program .

I heard with a Mercury Nemisis prop, you need to drop a pitch. I dont know about Solas props.

making sense now! thanks for the extra detail!
 
Ok...

got the boat Thursday, broke things in, and got over the 10 hour mark yesterday.

Again, the motor is a Yamaha VMax SHO (250). Delivered with a 15T x 15.75 Saltwater Series II prop (pretty sure that 15 pitch?). Prop seems fine overall. Boat is a L series 24 foot with the SPS + toon setup. With 2 adults and 2 teens (~500lbs), and 15 gal of fuel onboard, and bimini deployed, we were topping out around 42-44 mph (Garmin indicated). RPM's right around 6k, but not above.

Seems like I have performance on the table.

Other things I notice. turning at best speed/trim seems to cavitate/wash out the prop. trimming down to turn hooks up better and helps. Motor is mounted on the lowest settings, but that said, with trim fully down, and boat unloaded, the top of the anti-cav plate is 12-14- inches below the waterline, maybe even a little more. Not sure if that's normal or not.

Doing S-turns with the same loadout (no tube or pulling), seems to work best if I back down to about 4-4.5k RPM, and trimming down a good bit from my trim level at max speed. (trim at max speed is 3/4 up, trim for best turning is closer to half on the gauge)

Knowing I'm not going for max speed, should I be repropping? or am I pretty good?

I can't help but sit here and think a 4 blade model will hook up better for turning... and be nice and efficient when at idle speed so much of the time...
 
Give ,propgods.com a call
 
More top speed may be available, but more to the point of your question. What speed are you getting at dead idle and 500 RPM increments up to, say, 2000?

Turning at high trim angles is likely to cause prop ventilation at speed with most props. Also keep in mind the gear case diameter of your motor is bigger than most 115/90's. Props that work well on the smaller case will not fit yours. Love the Nemesis Pontoon on ours, but it's not for you.

You have a prop that seems to work well and the SWSII has a good reputation for what you need. It's unlikely changing is cost effective. But if you must, limit your research to pontoon rated props (Yamaha has those).
 
More top speed may be available, but more to the point of your question. What speed are you getting at dead idle and 500 RPM increments up to, say, 2000?

Turning at high trim angles is likely to cause prop ventilation at speed with most props. Also keep in mind the gear case diameter of your motor is bigger than most 115/90's. Props that work well on the smaller case will not fit yours. Love the Nemesis Pontoon on ours, but it's not for you.

You have a prop that seems to work well and the SWSII has a good reputation for what you need. It's unlikely changing is cost effective. But if you must, limit your research to pontoon rated props (Yamaha has those).

Thanks @PartyBarge, appreciate the response. I didn't clock it yet, so will do that next time out this weekend.

i'm at about 3.5mph at idle, 5mph @1000 RPM, 5.6mph @ 1200 RPM.

I'll get a better set of data when i can. only a few hours a day I can get above no wake speed, so it was a real challenge to break in the motor, lol...
 
Sounds like the prop is hooking OK at low prop RPM. A pontoon specific prop might be interesting, but that would be an expensive venture to, likely, not gain much.

BTW: As to top end, expect more of both speed and RPM with a lighter load or a following wind. Nothing wrong with the 6k you are getting considering the load and parachute deployed. Try to get data with both a lighter AND heavier load.
 
Also get your data WITHOUT bimini deployed. That’s going to muddle it all up big time. Also, I the bimini has a mph rating (I believe it varies a little bit based on type of bimini). Thus, I wouldn’t have it deployed when running at those speeds for both safety and longevity purposes.…not to mention possible warranty coverage. Double check your stickers and warnings with the bimini to verify the max speed rating for yours. You may or may not be fine. I think my curved electric bimini rating is something like 30 or 35 mph max on my 2017.
 
Also get your data WITHOUT bimini deployed. That’s going to muddle it all up big time. Also, I the bimini has a mph rating (I believe it varies a little bit based on type of bimini). Thus, I wouldn’t have it deployed when running at those speeds for both safety and longevity purposes.…not to mention possible warranty coverage. Double check your stickers and warnings with the bimini to verify the max speed rating for yours. You may or may not be fine. I think my curved electric bimini rating is something like 30 or 35 mph max on my 2017.
Good point. Dealer said it was ok to leave up "no matter what", but... I have always been told when renting boats off the Gulf in FL that the bimini should be taken down when going over 20-25 mph depending on model... I don't need warranty issues from me being stupid... i should say i can't help being stupid, but at least now i'll pay attention to the bimini rating, lol
 
Your cracking me up JCR! Ha, ha. Check for your boat. Some of the bimini‘s are rated for higher speeds. Always good to know those things. I didn’t realize our rating until someone pointed it out to me in these forums back in 2017. Of course its clearly labeled…but I had looked right past it…lol.
 
Your cracking me up JCR! Ha, ha. Check for your boat. Some of the bimini‘s are rated for higher speeds. Always good to know those things. I didn’t realize our rating until someone pointed it out to me in these forums back in 2017. Of course its clearly labeled…but I had looked right past it…lol.

Sadly, part of my job is to put those "captain obvious" messages in our software.. you know, the ones you just click through? like the labels on my boat i haven't read?

10 hours on it, and just saw yesterday that there was a big giant sticker next to the helm with a pre-departure check list... :p

I'll cuss at my users 10 less times each day now... ;)
 
Jcr159, not to muddy the water, but I don’t think your cavation plate should be below the water line. Seems to me that your engine may be mounted too low.
 
Jcr159, not to muddy the water, but I don’t think your cavation plate should be below the water line. Seems to me that your engine may be mounted too low.
yeah, i didn't expect it to be above the waterline... but it seems really, really low

either that, or i have water in the toons... rear sits about half in the water with no one on the boat... but the 250 is the max engine for my frame....
 
JCR, OK I have to ask. Did you check the depth of the cav plate at rest or at speed? I've never seen one as deep as your estimate that wasn't on a houseboat! Anyway for planning hulls it's at speed that matters.
 
JCR, OK I have to ask. Did you check the depth of the cav plate at rest or at speed? I've never seen one as deep as your estimate that wasn't on a houseboat! Anyway for planning hulls it's at speed that matters.

that was on the hook while swimming... just for giggles i tilted the motor to full down trim to see how deep it was... i'll try and get a pic this weekend.

it wasn't till i was typing up my handling results that it occurred to me that it was pretty deep... if i had to guess, i'd say the anti cav plate was roughly in line with the bottom of the center log. never having looked at a pontoon outboard setup before, it didn't register that this might be off... i'm not sure if that's "right" to get clean flow, vs. turbulent flow behind the toon itself or not...
 
some updates..

Need to get in touch with propgods...

on to the observations.

Checked cav plate again, and it actually seems like it is a few (3-6 inches) ABOVE the bottom of the center tube, but 8-12 inches below the waterline at rest, no load on the boat. motor is mounted as low as it can go. Not sure if that's good or bad yet. stay tuned...

pulled our tube for the first time this weekend. Airforce g-force 3. 2-3 young teen girls riding. 2 adults onboard, 15 gal fuel, bimini deployed and a heavy cooler. Found that I needed to trim down to 1/4-1/2 to get hookup without getting a lot of cavitation, especially when turning... I could trim almost normal after getting to speed (3/4 on the trim gauge) in a straight line..

We also ran with the bimini down (stored), with 4 heavy adults, and 3 teen girls, 15 gal fuel, and heavy cooler for speed, and logged the following:

  • 1000 RPM - 4.9 mph
  • 1500 RPM - 6.9 mph
  • 2000 RPM - 10.1 mph
  • 2500 RPM - 12.7 mph
  • 3000 RPM - 16.5 mph
  • 3500 RPM - 19.1 mph
  • 4000 RPM - 21.3 mph
  • 4500 RPM - 26 mph
  • 5000 RPM - 31.8 mph
  • 5500 RPM - 36.2 mph
  • 5800 RPM - 40.2 mph
With 2 less adults (400 lbs or so), we could top out at 5800-5900 RPM, and 42 mph

No idea what all this means, lol. I don't have experience towing on a pontoon... My experience there goes back to the late 80's/early 90's with some glastron boats with i/o drives.. whole different ballgame and handling...

Thanks for any help!
 
For what it’s worth, here’s the boat with just me on it the day we took delivery…. Sits pretty low in the back, but not too different than others I’ve seen?

76430B48-5BE3-4031-BD0B-8450976B7FDB.jpeg
 
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