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2006 2050 RL with Yamaha Vmax 115 SHO — 27mph at 6100 RPM with 13.625x14 prop — normal?

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RFfieldlabs

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Hi all, looking for real world numbers from anyone with a similar setup. Running a 2006 2050 RL with a Yamaha VF115 SHO, freshly serviced, 980 hours. Just installed a genuine Yamaha K series 13.625x14 aluminum prop. Motor height has cavitation plate roughly flush with hull bottom. Getting 27mph at 6100 RPM WOT with 2 people on calm water. Little ventilation. Is this normal for this hull or am I leaving speed on the table? Previous owner/memory suggests this boat did more but I don't have verified numbers. Any 2050 RL owners with a 115 SHO please share your real world WOT speed and RPM. Thanks
 
You mention if this is normal for this hull. What hull do you have: normal 2 log pontoon or one of the various tritoon hulls (for instance, SPS or ESP)? Also, do you have lifting strakes? Your other information is very useful. If you can provide this additional information, it can help people chime in more accurately.

That said, if you have a traditional bi-toon, you are pretty much at perfect RPM’s at WOT with a light load on calm water. You are also right in at the top or mid range max speed with your set up depending on if you have lifting strakes or not with two pontoons.

Now, if it is a tritoon hull, you should be able to get into the low 30’s with your boat and motor and I would be curious if you pontoons are clean or not (potentially holding you back a little bit in mph).
 
We have a 2021 S21, Bi-toon, no strakes, with a 115 VMAX SHO, full fuel, 2 adults, top stowed, 15 pitch, 4 blade Hustler aluminum propeller, 29 mph @5850 rpm, top up, 28 mph, same load. I don't know how the RL compares to SL from a weight perspective. I'd say you have yours dialed in pretty well.
 
RF: with the data you gave and the standard 2:15to1 of your motor, the calculated slip is 28%. That is not great, but is better than the standard aluminum "K" provides in some applications (those props frequently run well more than 30% on some pontoons). With higher the load, RPM might come down some, but slip will definitely increase (meaning loss of speed). A bit better performance is likely available with a pontoon rated prop. It's a matter of how much you want to spend for 2-4 MPH.

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I have 2017 21' SLX with ESP center toon and a VF115 SHO motor. Running the Turning Point Hustler 4 blade 15 pitch.. I get 32 MPH @ 6000 RPM
 
Vikingstaff said:
You mention if this is normal for this hull. What hull do you have: normal 2 log pontoon or one of the various tritoon hulls (for instance, SPS or ESP)? Also, do you have lifting strakes? Your other information is very useful. If you can provide this additional information, it can help people chime in more accurately.

That said, if you have a traditional bi-toon, you are pretty much at perfect RPM’s at WOT with a light load on calm water. You are also right in at the top or mid range max speed with your set up depending on if you have lifting strakes or not with two pontoons.

Now, if it is a tritoon hull, you should be able to get into the low 30’s with your boat and motor and I would be curious if you pontoons are clean or not (potentially holding you back a little bit in mph).
Click to expand...
I have the standard 2 log hull. My logs are clean but the water absolutely slams the bottom of the boat when floored it’s kinda acting like a natural brake. I feel like adding aluminum underskinnijg would help and maybe even Inprove the bit of ventilation in the propnim getting. Before I ran a 12 pitch 13 diameter getting around the same speed as I do now with my new 14 pitch along with staying near the max rpm of the vmax engine. Kinda leads me to believe that the amount of airated water hitting the prop at speed is really holding me back
 
Vikingstaff said:
You mention if this is normal for this hull. What hull do you have: normal 2 log pontoon or one of the various tritoon hulls (for instance, SPS or ESP)? Also, do you have lifting strakes? Your other information is very useful. If you can provide this additional information, it can help people chime in more accurately.

That said, if you have a traditional bi-toon, you are pretty much at perfect RPM’s at WOT with a light load on calm water. You are also right in at the top or mid range max speed with your set up depending on if you have lifting strakes or not with two pontoons.

Now, if it is a tritoon hull, you should be able to get into the low 30’s with your boat and motor and I would be curious if you pontoons are clean or not (potentially holding you back a little bit in mph).
Click to expand...
No lifting strakes by the way
 
Without lifting strakes, and having a 2 log R-series (which is a heavier model), your description of how it rides makes sense. It is going to plow hard through the water, not get up on plane, etc… Underskinning would smooth out the ride experience a little bit for occupants. Might even provide a small nudge at WOT. It is mainly a comfort thing though.

You could do better with the style of prop to minimize slippage. Ken @ Propgods has advised many members, and knows his stuff inside and out. However, for the expense of a new prop on a 2 log, non-lifting strake pontoon…I think your best case scenario is maybe +2mph at WOT.

You simply have a pontoon boat/hull built for slow cruising in style and comfort. Your mph is actually pretty good given all those variables.
 
I considered adding a wave shield for our 2080 RL, but lost interest in the project. The comfort/drag gains appear to be useful, however added weight is a factor too. I suspect you have the same 23" toons we have, those are not good for speed.

If you go for the upgrade be sure to also add the side-skirts to deflect water away from the "M" brackets between the toons and the deck. That area is a significant source of drag for pontoons like ours. Decreasing drag will reduce the slippage of your current prop too.

Vikingstaff said:
You simply have a pontoon boat/hull built for slow cruising in style and comfort. Your mph is actually pretty good given all those variables.
Click to expand...
 
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PartyBarge said:
I considered adding a wave shield for our 2080 RL, but lost interest in the project. The comfort/drag gains appear to be useful, however added weight is a factor too. I suspect you have the same 23" toons we have, those are not good for speed.

If you go for the upgrade be sure to also add the side-skirts to deflect water away from the "M" brackets between the toons and the deck. That area is a significant source of drag for pontoons like ours. Decreasing drag will reduce the slippage of your current prop too.
Click to expand...
Thanks for the tip. I actually have 20 foot toons tho
 
Ahhh...not referring to the length of the toons. It is the diameter at only 23 inches (23") that is a hinderance to speed when compared to more modern 25" tubes (or larger or a tri-toon). Extra running surface helps with a better/lower drag transition to planning from displacement (as do strakes).
 
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