Best prop for idling/no wake boating?

[Michiman]

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?

View attachment 32786

Nice looking Benny! As for sitting low in the stern, it looks about right to me. We’re you able to check the position of the cavitation plate at speed?

With regard to RPM and speed, what is the manufacturer’s recommended range? Speed wise, you definitely seem to be on the lower end, given the size of your boat and horsepower.

 

[jcr159]

Nice looking Benny! As for sitting low in the stern, it looks about right to me. We’re you able to check the position of the cavitation plate at speed?

With regard to RPM and speed, what is the manufacturer’s recommended range? Speed wise, you definitely seem to be on the lower end, given the size of your boat and horsepower.

didn't get a chance to check the plate at speed. that'll be next time out for sure. Thanks for the nice compliment!

Looks like 5-6k rpm is the recommended max.

I did determine that at rest the cav plate is a good bit above the bottom of the center toon.. we'll see next time out how that translates at speed...

I did hear back from Ken at PropGods, and he said my numbers looked reasonable from what he's seen. but said I could try a 4 blade prop that should help with some of the watersports stuff I'm doing... still figuring out if i wanna try another prop, and am out of town for the next 2 weeks...

 

[SLXGUY]

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...

I have a 2021 23SLX with Yamaha VMax Sho 250, the SPS+ and same prop. I would say don't change a thing......it is the perfec t setup. However, I would suggest that you should not trim up as far as you seem to be doing. I am normally at cruise about 1/8 to1/4 up tops. I only go to 3/4 up if in very shallow water. If I'm at WOT I might go to 3/8 depending on load. Of course all of this is based on the guage adjustment and engine height. But as you get used to the boat you will get a better feel for the trim. Sounds like your lake may be too small to really "open up" this engine .... at WOT with 2 on board and a half tank of gas I'm in the high upper 40's and depending on water conditions I can hit 50 on the gps.

 

[jcr159]

I have a 2021 23SLX with Yamaha VMax Sho 250, the SPS+ and same prop. I would say don't change a thing......it is the perfec t setup. However, I would suggest that you should not trim up as far as you seem to be doing. I am normally at cruise about 1/8 to1/4 up tops. I only go to 3/4 up if in very shallow water. If I'm at WOT I might go to 3/8 depending on load. Of course all of this is based on the guage adjustment and engine height. But as you get used to the boat you will get a better feel for the trim. Sounds like your lake may be too small to really "open up" this engine .... at WOT with 2 on board and a half tank of gas I'm in the high upper 40's and depending on water conditions I can hit 50 on the gps.

It is definitely small to say the least... but i definitely haven't hit more than 44 with 2 on board... maybe i'll take a look more at the mount height for sure...

 

[Vikingstaff]

I agree with SLXGuy. I think you have a good prop, and the cost vs. performance changes would not be worth the cost. I really think revising your motor one spot higher will really be the difference in maximizing your performance. That said, you are in the RPM range, and really not too far off of what you can top out at anyway. Since you are on a smaller lake, might not even be worth messing with the motor height. Of course, I would probably do it just to know I am dialed in, but again maybe not worth the hassle if you cannot really open it up much on your lake anyway.

 

[SLXGUY]

Here is a link to determine prop slip: https://www.mercuryracing.com/propellers-overview/prop-slip-calculator.html

Mine is 6% and yours should be very close if rpms are correct, speed is gps, relatively light load and engine height correct. The numbers you posted above (42 mph) with 7 people, seems pretty good to me since much depends also on how the weight is distributed. My engine is mounted a low as it can go. Here's a pic of mine.....looks very similar in how the aft of the pontoon looks.

 

[DejaWiz]

Adding this YPB entry for a Benny 2275 RCW (it's an older 2012 with the VF250LA) using a SW2 15.5x17 prop...more-so for the sake of comparison to your own results:

PB_BNT_2275RCW_VF250LA_2012-05-14_PNT | Yamaha Outboards

yamahaoutboards.com

I agree with Vikingstaff that your boat seems to be dialed in beautifully, so tinkering around with a prop change probably won't be worth it in the long run given your lake restrictions/limitations.

Beautiful boat, jcr159!

 

[jcr159]

Here is a link to determine prop slip: https://www.mercuryracing.com/propellers-overview/prop-slip-calculator.html

Mine is 6% and yours should be very close if rpms are correct, speed is gps, relatively light load and engine height correct. The numbers you posted above (42 mph) with 7 people, seems pretty good to me since much depends also on how the weight is distributed. My engine is mounted a low as it can go. Here's a pic of mine.....looks very similar in how the aft of the pontoon looks.

Adding this YPB entry for a Benny 2275 RCW (it's an older 2012 with the VF250LA) using a SW2 15.5x17 prop...more-so for the sake of comparison to your own results:

PB_BNT_2275RCW_VF250LA_2012-05-14_PNT | Yamaha Outboards

yamahaoutboards.com

I agree with Vikingstaff that your boat seems to be dialed in beautifully, so tinkering around with a prop change probably won't be worth it in the long run given your lake restrictions/limitations.

Beautiful boat, jcr159!

thanks for the votes of confidence!

I think the last peace of mind will be checking the cav plate underpower on plane... and then i think i'm done obsessing...