Prop Question / 24SLi and 115 Opti Max

Shawn

Well-Known Member
Messages
229
Reaction score
137
Location
Ohio
Hi,

I've seen lots of other prop questions, so I thought I would share mine as well. Currently, I have a 2011 24SLi with a 115 Merc Opti Max. After break in with two people on board and a full fuel tank I hit 28mph via GPS. Problem is I was at about 4800 RPM. Now, with 5 on board and close to a full tank of gas I am getting 4600 RPM and getting speeds of 23-25mph. Speed is also a bit lower when the logs are real dirty (but I can fix that).

I've got a call into the dealer and should hear back later this week. I'm thinking I should probably go to a 15P prop, but wanted some advice from the "experts"!

Also, since I keep the boat 2 hours away in a slip, how hard is it going to be to change the prop. I don't really want to pull the boat and take it to the dealer if I don't have to. Once I get the ideal prop I think I'd like to get one that is SS, however, need to find the correct set up first.

Thanks for the help.

Shawn
 

Geoffrey & Brenda

Moderator
Messages
1,038
Reaction score
120
Location
Lawrence Kansas
Hi Shawn, it sounds like you need to change props, as you are leaving a lot of rpm behind. You should get your rpm's close to the max rating with an average load on. Ericsher knows prop 'science' better than i, let us know what your current prop is, and perhaps we can guide you in the right direction!
 

ericscher

Well-Known Member
Messages
531
Reaction score
18
Location
Buckeye Lake, Ohio
No, no, no.... I just know a few things based on personal experience and that of people I've met. I'm no expert.

Now Ben & Suzy's brother just went through this on a similar boat with a 115hp Optimax.

Here's what they just got done saying about it. The post in question is right here.

I suggest you PM them and get the prop diameter as well.

We just went through this same scenario with my brother's 2050RL with a Yamaha F115. It came with a Yamaha 17p running in the 5500 rpm range. I'd hate to tell you how many different props we've tried in the 13p-15p range and just how much they differed. Most of the 13p's ran in the 6000 range and had more speed than the rest, regardless of whether it was a 3 or 4 blade. Prop of choice: 4 blade 13p @ 6000. Best top speed and best cruising speed. Top that off with better fuel economy throughout the entire rpm range. :D The motor and my brother are very happy.
 

Shawn

Well-Known Member
Messages
229
Reaction score
137
Location
Ohio
No, no, no.... I just know a few things based on personal experience and that of people I've met. I'm no expert.

Now Ben & Suzy's brother just went through this on a similar boat with a 115hp Optimax.

Here's what they just got done saying about it. The post in question is right here.

I suggest you PM them and get the prop diameter as well.
Left the most important detail out of my post...

Current prop is 13.25x17pitch.

Shawn
 

Fyrfightr

Well-Known Member
Messages
149
Reaction score
2
The original Yamaha prop is a 13.25 x 17p. While we ended up settling on the Solas 4 blade aluminum 13.25 x 13p, it really wasn't the best choice of the props we tried. That title went to a Solas stainless 3 blade. But....what we found with the Yamaha F115 is that when a stainless prop is installed, the extra weight of the prop will make the gears ratchet/lash while at an in gear idle up to about 900 rpms. This happened with EVERY stainless prop we tested and none of the aluminum props. It's caused by the weight of the prop loading and unloading the gearset between firing strokes of the engine. After speaking with a couple of prop shops, this is a common complaint with the Yamaha F115 and the Mercury 115 that uses the Yamaha powerhead. Idling around the dock it was annoying and coupled with not knowing if it would cause any damage to the gears in the long term, we chose not to run a stainless for this reason.

The best performing prop of the group we tested was the stainless Solas New Saturn 14 x 13p. These are the new style pusher props developed for pontoons and they work very,very well. Unfortunately, this new blade design is not offered in aluminum......yet.

FYI : Yes....we did try other brands of props.
That's interesting. All of the Yamaha test I have found have used Stainless Props. If this is an issue I would be complaining to your dealer.
 

seven twenty

Active Member
Messages
30
Reaction score
0
Location
Iowa
Here is a link to a Yamaha performance bulletin: 24 Sli w/115TLR http://www.yamaha-motor.com/assets/products/otb/bulletins/bulletin_4stroke_midthrustjetport_pp_bnt_24sli_f115tlr_2010-10-13_pnt.pdf

They also have a couple of pages for you bigger motor (150) or smaller motor. Just look under performance bulletins.

Yamaha is offering a 14X13 in their Pontoon Performance Series of props. Any idea if/what the difference with theirs and the Solas would be? It's all new to me so other than quality is there any?
 

seven twenty

Active Member
Messages
30
Reaction score
0
Location
Iowa
Sorry if I wound you up Ben. Like I said, I consider myself a newbie. I posted the link so if some others would like to see some factory #'s they could look. I also realize that the #'s they are posting don't seem to be that close to real #'s. Maybe a good reference to guage off of??? I know I'm happy with the difference, especially the GPH. :)

I am in need of a different prop, and was thinking the 14X13 would be a good try. I don't have access to a variety so I appreciate all of the info that is posted on this site. When it comes to quality I have no idea good, bad, or ugly. At WOT i'm only turning 5100 with a 13.75X15 so I'm thinking the 14X13 would be my best bet at getting better performance and not having to do alot of testing.

Again, I, as well as alot of others I'm sure, appreciate all of the info you and others do post. Thx
 

spinzone

Well-Known Member
Messages
663
Reaction score
146
Location
Marvin, NC
Seven Twenty- No need to apologize. Some people have the genetic urge to bully people for trying to help. Making snide comments does not earn respect in my book.

Feel free to post, ask, and reply anytime you feel you can contribute to the overall knowledge of this site!
 

Shawn

Well-Known Member
Messages
229
Reaction score
137
Location
Ohio
Hi,

I've seen lots of other prop questions, so I thought I would share mine as well. Currently, I have a 2011 24SLi with a 115 Merc Opti Max. After break in with two people on board and a full fuel tank I hit 28mph via GPS. Problem is I was at about 4800 RPM. Now, with 5 on board and close to a full tank of gas I am getting 4600 RPM and getting speeds of 23-25mph. Speed is also a bit lower when the logs are real dirty (but I can fix that).

I've got a call into the dealer and should hear back later this week. I'm thinking I should probably go to a 15P prop, but wanted some advice from the "experts"!

Also, since I keep the boat 2 hours away in a slip, how hard is it going to be to change the prop. I don't really want to pull the boat and take it to the dealer if I don't have to. Once I get the ideal prop I think I'd like to get one that is SS, however, need to find the correct set up first.

Thanks for the help.

Shawn
Tried a new prop this weekend - 13.75x15. RPM's went up to about 5000-5100 and speed was 24-25mph. I think it's probably apropriate to try one more prop - 13.85x14 as I should be getting a bit higher in the RPM range. I will note that the pontoon logs need a bit more cleaning - not real dirty but it will make a slight difference.

Shawn
 

Shawn

Well-Known Member
Messages
229
Reaction score
137
Location
Ohio
Dealer is going to order me a 14x13 prop to try this weekend. Hopefully this will be the one...

Shawn
 
Top