Back to the main site

2275RL / Yamaha 115 trim issues cavitating : /

a little bit of an update on my issues... had a friend double check my speed yesterday just for a solid start and his boat was at 21 mph and gps said 21 as well running at 5500 rpm...he said my boat from behind was really digging hard in the water ...so ive got some work on my hands getting the right set up to help my speed and Gas mileage because im drinking the gas and not going anywhere fast ..
 
IF your motor has the typical 2.15 gears, your calculated slip is ~42%. Clearly the prop isn't, or can't, do the job is should be doing. In just speculating, IF your slip was a more nominal 15%, the speed would be ~31 MPH. Something about the prop itself or the rigging of the pontoon won't let it operate in the realm where is needs to be.

On a somewhat related side note: Just for grins, I put my old generic Yamaha 3-blade 15p on (motor is still up one hole). It worked well for putting about at around 1500 RPM and ~5 MPH. Was still OK up to around 4000 RPM and 15 MPH. But, turned to crapola above that, running about 5800 RPM and 20.5 MPH. I could hear the motor unload as I put the power to that prop. That was all with 3/4 fuel and three aboard. Not only is it a poor choice for our pontoon, but it really hates the motor up any at all. Need to get the motor full down and back to the 13p Nemesis (or the 12p Talon for heavier loads/towing).
 
Last edited:
Sorry I havent updated lately but work has had me out of the country ....but i had time yesterday to take the boat out on a clear calm mild wind day to get some more data..... what i noticed was you could feel the boat pull up to about 4100 rpm and the gps was right at the 19 mph .... i pushed the throttle on up to 5800 rpm (which is my WOT) and you could feel and hear the boat was just revving up and sloshing water and the mph barely hit 21 mph so basically from 4000rpm up is just burning gas but not going anywhere any faster ..... I will be able to lower my engine 1 more hole ... i didnt think it would drop down but more investigation is showing it will move down one hole ..... im hoping this will help...i am going to pull the boat out and drop the engine and take it back out for a ride
 
Great! Getting your motor full down will help, but my bet is you still need a better prop.

I now have our motor full down again and running the Nemesis 13p. Towed a medium I/O about 3 miles a couple days ago. Worked great running about 2000 RPM and 5.2 to 5.5 MPH. Would have run faster, but was concerned about pulling the smallish cleat off their boat. Sure feels good to get back to what works best! The only use I'll have for the Talon 12p is for a full house and towing a tube.
 
Sounds to me like the wrong prop - you're hitting the upper limit of the props ability to overcome the forces working against it (water, wind, drag etc.) and so the power from the engine is just wasted. More surface area on the prop - usually in the form of diameter - will reduce that slip and put the power to work. But too much prop and you'll potentially see a drop in WOT RPM which is equally bad. Also too much diameter and you'll be sucking air and ventilating.

It's possible there is very turbulent water caused by the hull above 20mph and regardless of prop there is less "clean" water to bite into.

Also possible that you have a lot of growth on your toons adding a lot of drag, or water in the toons so there is more weight to push and less buoyancy.

Clearly a lot of things could be wrong and you'll have to ask a lot of questions and try different things. If it becomes too much of a headache just sell and buy a new tritoon!
 
Update on my prop/ motor issues...... I lowered the engine down 1 hole and I ended up going with a Solas 13.75 x 13p stainless prop and my 2275RL went from 21 mph 5500 WOT and 0 trim capability to 26 mph and 6000 WOT and 1/2-3/4 trim option ..... I was shocked at how much better this boat feels and pulls thru the RPM range ......and even more shocked that the speed gained 5 mph!! Yes i know the water / weather has some to do with those speed increases...but still very pleased
 

Attachments

  • 252045943_1377502392646764_468256874344428692_n.jpg
    252045943_1377502392646764_468256874344428692_n.jpg
    148.6 KB · Views: 30
  • 254729382_585202492691459_4292871844295166891_n.jpg
    254729382_585202492691459_4292871844295166891_n.jpg
    191.5 KB · Views: 30
  • 253403445_920854545478692_3864503973615739235_n.jpg
    253403445_920854545478692_3864503973615739235_n.jpg
    159 KB · Views: 29
  • 251497076_961606597759668_978169532144955516_n.jpg
    251497076_961606597759668_978169532144955516_n.jpg
    40.7 KB · Views: 26
Last edited:
Wow. Thanks for the update
 
That’s awesome! Glad you got such good results. Enjoy the water.
 
Shame that there are so many bad props out there on boats. It's literally the only thing that transfers work from the engine to the water so proper match is critical. A bad prop is equivalent to running a marathon in flip flops or steel-toed boots...

OP glad you got this worked out!
 
Potomacbassin’ said:
Shame that there are so many bad props out there on boats. It's literally the only thing that transfers work from the engine to the water so proper match is critical. A bad prop is equivalent to running a marathon in flip flops or steel-toed boots...

OP glad you got this worked out!
Click to expand...
Hey Hawaiians can do anything/everything in flip flops!!! Ha!
 
Potomacbassin’ said:
Shame that there are so many bad props out there on boats. It's literally the only thing that transfers work from the engine to the water so proper match is critical. A bad prop is equivalent to running a marathon in flip flops or steel-toed boots...

OP glad you got this worked out!
Click to expand...
I never realized something as simple as a 15 min swap of props and 30 min dropping the engine could make such a huge change.... i found myself scratching my head thinking wow is this right ?? .....your correct that there is untelling how many boats that are leaving alot of power/efficiency on the table all due to a prop change........... but then again finding the right prop can be very $$$$ I got lucky and had several buddies that had props laying around that I could try out
 
Bigtime57 said:
...... I lowered the engine down 1 hole and I ended up going with a Solas 13.75 x 13p stainless prop and my 2275RL went from 21 mph 5500 WOT and 0 trim capability to 26 mph and 6000 WOT and 1/2-3/4 trim option .....
Click to expand...
IF you have the typical gear ratio (2.14) for your motor, your calculated slip is now a very reasonable 24%.

IF you have 2.3 gears, the calculation is even better (19%).

Great results are obvious when a pontoon is rigged for YOUR use with a prop well matched to YOUR speed and drag profile. Having some trim range available also can help when running a less than optimal weight distribution too. Hope you have more time in your boating season....
 
This is why I don’t get people not ‘checking into potential/expected performance when they are buying an expensive pontoon - particularly those that pay $ for higher HP or tritoons. At purchase you can often spell in the ability to “test” some props to dial in the boats performance because it can be so variable.

Those that sometimes post in here ”I trust the dealers decision, they sell these all the time” are really naive to the dealers potential conflicted interest, or lack of experience “dialing in” a specific model/layout/motored boat, or just compromising the prop based on what’s on their shelf, etc...

Sometimes dealers do a great job, sometimes they do not. I think it’s just good to be dialed in regardless of ones intended uses. Often better fuel efficiency or performance (maybe one values cruise RPMs or hole shot, or top end more…) or simply getting one’s monies worth out of a pricey purchase.

One of the reasons I LOVE this forum. So many people that give helpful advice, and a great collection of posts over time to do one’s researich on other people’s real world experiences.
 
Last edited:
Bigtime57 said:
I never realized something as simple as a 15 min swap of props and 30 min dropping the engine could make such a huge change.... i found myself scratching my head thinking wow is this right ?? .....your correct that there is untelling how many boats that are leaving alot of power/efficiency on the table all due to a prop change........... but then again finding the right prop can be very $$$$ I got lucky and had several buddies that had props laying around that I could try out
Click to expand...

Agreed. There are several shops out there that offer a prop swap service but for the average boater they're likely not going to go through all that hassle. And it is a bit of a guessing game - prop selectors or guys in the biz can recommend a range of props, but testing is the only way I know to find out for sure.

I went through 4 different props in my case but I was hellbent on getting it dialed in. Dealer was no help as they put an undersized prop on and argued it "wasn't going to get better than that". Test results proved them wrong. I'd like to think a better mousetrap can be developed beyond DIY or boating forums, but perhaps the economics don't support one.
 
Speaking of prop swaps.....my dealer told us we could try an Enertia 15P to see how it compared to our 17P. He said the holeshot would be better. We have absolutely no complaints with it's performance now but Ive had people tell me that the 17P doesn't belong on a Mercury 150. Thoughts?
 
BigKahuna said:
Speaking of prop swaps.....my dealer told us we could try an Enertia 15P to see how it compared to our 17P. He said the holeshot would be better. We have absolutely no complaints with it's performance now but Ive had people tell me that the 17P doesn't belong on a Mercury 150. Thoughts?
Click to expand...

I run a 17p Enertia/Q3 on my 250 and I can't make redline. Don't get me wrong, it's a fabulous prop for me and is the perfect balance of top speed, hole shot and efficiency, but if I can only get 5800RPM at WOT then I would guess you're well south of 5500 with your 150?

But the Enertia in my opinion is not a magic bullet, so if your priority is hole shot then I think other props may perform slightly better - I think a Mirage Plus or even a 4-blade Rev 4 should do better. But you'll lose top speed in exchange.

Datalog your 17's performance numbers throughout the RPM band then do the same for the 15p - the numbers won't lie and my guess is your hole shot will be slightly better, fuel efficiency better at low speed but worse at high speed, and a loss of 2-3mph on the top end. But your WOT will also be higher and keep the engine happier over time.
 
BigKahuna said:
Speaking of prop swaps.....my dealer told us we could try an Enertia 15P to see how it compared to our 17P. He said the holeshot would be better. We have absolutely no complaints with it's performance now but Ive had people tell me that the 17P doesn't belong on a Mercury 150. Thoughts?
Click to expand...
I kind of lean into the dealerships advice on this one. I am running on 16p Enertia on our 200 Mercury Verado Pro. After adding the Sea Legs, I could almost see myself going down to a 15p just to tweak performance a bit with the boats weight gain.

Anyway, if they are offering to let you give th 15p a try, I’d take them up on it. Track the numbers on both as Poto mentioned, and then you’ll know for sure. I think you’ll be better off with that 15p, but only one way to know for sure.
 
I concur with Vikingstaff. I have a Enertia 15 x 15 on a Yamaha 150 and it performs great at the low and mid range, and it respond well to trim. It may not produce the fastest top speed but it pulls well no matter how many are on board.
 
Potomacbassin’ said:
I run a 17p Enertia/Q3 on my 250 and I can't make redline. Don't get me wrong, it's a fabulous prop for me and is the perfect balance of top speed, hole shot and efficiency, but if I can only get 5800RPM at WOT then I would guess you're well south of 5500 with your 150?

But the Enertia in my opinion is not a magic bullet, so if your priority is hole shot then I think other props may perform slightly better - I think a Mirage Plus or even a 4-blade Rev 4 should do better. But you'll lose top speed in exchange.

Datalog your 17's performance numbers throughout the RPM band then do the same for the 15p - the numbers won't lie and my guess is your hole shot will be slightly better, fuel efficiency better at low speed but worse at high speed, and a loss of 2-3mph on the top end. But your WOT will also be higher and keep the engine happier over time.
Click to expand...
Okay gentlemen you all convinced me to swap to the 15P but I'll stick with the Enertia line. I had a Mirage Plus on my I/O and loved it but I'll stick with Enertia. I've had this 17P for 2 seasons and loved its performance so we'll see how the 15P performs next spring. Took the boat out today and will be dropping it off at the dealer tomorrow for some warranty work.....
 
You must log in or register to reply here.
Back
Top