Prop upgrade for speed

Michael Lyman

Active Member
Messages
31
Reaction score
23
Location
Northeast Ohio
I would like to upgrade my prop to get a few more miles per hour faster, any suggestions on a good upgrade or suggestions regarding this thought. Love my tritoon with my 115 just need a little more.

I realize that this is not a speed boat, just looking for a little bit more for pulling tubers. Thanks in advance for the thoughts.
 

goldnrod24

Moderator
Messages
2,763
Reaction score
1,800
You need to provide a lot more info if you want a real answer to your question. Boat model and length, current prop make and model as well as pitch and diameter, current GPS-verified top speed and rpms.
 

Michael Lyman

Active Member
Messages
31
Reaction score
23
Location
Northeast Ohio
You need to provide a lot more info if you want a real answer to your question. Boat model and length, current prop make and model as well as pitch and diameter, current GPS-verified top speed and rpms.
Thanks....
  • 2016-21 foot Bennington SX Tritoon
  • 115 HP Mercury 4 stroke
  • I believe prop is factory, apologize dont know more there but can look up if you can help me on how to do so
  • RPMs currently run 5000
Thanks in advance...any thoughts are appreciated.
 

swiftm

Well-Known Member
Messages
736
Reaction score
369
Location
Traverse City, Michigan
Pitch and diameter are stamped/engraved on the hub of the prop. Sorry can’t help with your original question. Others here definitely knowledgeable about it though.
 

goldnrod24

Moderator
Messages
2,763
Reaction score
1,800
I believe prop is factory, apologize dont know more there but can look up if you can help me on how to do so

No such thing as a "factory" prop. Engines are shipped without a prop; it's the dealer's job to prop the boat. The name of the manufacturer, model and a number representing the diameter and pitch are engraved or stamped on the prop. See photo below.

We will need that info before making any suggestions.propsize.jpg
 

goldnrod24

Moderator
Messages
2,763
Reaction score
1,800
If your WOT (wide open throttle) rpms are only 5000, you are leaving speed on the table. However, you mention pulling tubers. A fixed blade prop will either give you a great hole shot (acceleration from a dead stop) or top speed, but not both.

Never ASSume that the dealer has provided the optimum prop. Mine swore they water tested 3 props and picked the best. That was BS. I repropped and got another 5 mph at lower rpms. To this day, my dealer thinks I am BS-ing him. LOL.
 

Titletown Mike

Well-Known Member
Messages
56
Reaction score
124
I agree with goldnrod24 above. You either select a prop for better top end speed or for a better hole shot. A good dealer will talk to you about what is more important to you and provide the appropriate prop.

Once you provide the prop info, we can provide feedback/suggestions.
 

kaydano

Well-Known Member
Messages
4,269
Reaction score
2,100
17 pitch on a 115 on a pontoon boat sounds too steep...
 

2fast4u

Well-Known Member
Messages
191
Reaction score
187
Location
central North Carolina
You stated your rpms were 5000 which is way to low in your picture you have a 17 pitch prop which is way too tall, on my benny with a 115 Yamaha I use a 13 pitch prop which give me 6000 max rpms. I also have a 15 pitch which gives me 5700 rpms re prop your boat is what I suggest. my fastest speed came with the 13 pitch prop.
 

Vikingstaff

Well-Known Member
Messages
2,312
Reaction score
3,217
Location
Michigan
That is significantly over propped with a 17p. As others said above, you need to get down much smaller in pitch on a 115hp. That will get your RPM’s into a better/manufacturer recommended range, and dramatically improve performance.

I have a 200hp and I am running a 16p, and now that I added Sea Legs, considering dropping to a 14-15p myself.

Not sure who the dealer was who dropped a 17p on that thing, but goodness. I’d have a talk with them, because that’s silly too big.

I’d go with the 13p recommended above...like today. ;)
 

Michael Lyman

Active Member
Messages
31
Reaction score
23
Location
Northeast Ohio
Thanks for excellent input. Seems to be the consensus. Any recommendations on specific props or more of a dealer call? I bought used so prop was what original owner had.
 

2fast4u

Well-Known Member
Messages
191
Reaction score
187
Location
central North Carolina
Thanks for excellent input. Seems to be the consensus. Any recommendations on specific props or more of a dealer call? I bought used so prop was what original owner had.
THis is what I finally got Mercury Black Diamond (QA2032X) 14" x 13p Bought it from www.iboats.com for $145.00 including the hub kit for a Yamaha motor. By the way the Mercury Props require you to buy a Flo-Torque hub kit (835271Q2) this adepts the prop to a Yamaha motor. Order prop and hub kit.
 
Last edited:

Michael Lyman

Active Member
Messages
31
Reaction score
23
Location
Northeast Ohio
All- ended up going with a 13.8 x 13 spitfire four blade. Will install over next week. Any thoughts on performance improvements you think I’ll see around speed? Thanks for all the help, dealer helped me spec as well and all agreed that 17 pitch was not correct
 
Top