Prop size

koch0134

Member
Messages
10
Reaction score
0
Hello!
As I think I have stated in other threads, I have a 2003 Bennington 2275RL (22') with a Yamaha 115 on it. I am currently getting about 22 mph top speed. I am wondering if anyone else has a similar set up and what size/pitch prop they are using. It seams to me that when I have talked to others they said I should be getting closer to 30 mph out of it. It also has listing strakes, not sure if that has anything to do with the lower speeds. Any help is appreciated! Thanks!
 
On the Yamaha Website it is suggesting I use a 19 pitch prop. I currently have a 15 on it and at max RPM I get about 6400. That is just me and the few things we have on the boat. Thanks again.
 
Your numbers don't add up. I have a 150 on our 2275rl and run a 15p Enertia and WOT is 6100.
 
Im not sure what you mean. I was out today and with a 13 pitch got 6800 WOT and with a 15 pitch got 6400 WOT. From the research I have been doing it is looking like my RPMs should be lower at WOT. If I up the pitch will that lower my RPMs at WOT?
Like I said the yamaha website told me to run a 19 pitch which kinda surprised me.
 
I think your tach is giving you an incorrect reading. Do you have 2 or 3 tubes?
 
I have two tubes. I recently bought it used from the dealership. They said the tech and all gauges were checked and accurate. What numbers are wrong? Am I getting to many RPMs out of it? I tried a 13p and got 6800 RPMs at WOT.

Im not sure what to do. I might just get the 19p as suggested by the Yamaha website. Can I damage the engine if it is touch pitch? I am thinking if I go from a 15p to a 19p I should get close to 10 more MPH out of it. Or am I wrong?

Thanks again for all of your help and incite!

-Cory
 
Is there a dealer near you that will let you try different props? Forgot to mention I have 3 tubes with strakes and top out at 39 mph.
 
Yes, you can damage your engine by over or under revving (lugging) your engine. Like Carl said, the numbers you provide don't sound right. I'd start by determining what the WOT RPM suggested range is for your engine. You might also want to contact Ken at propgods.com for some advice. Good luck...
 
Koch, I have a 2012 2275RL with a Yamaha F115 with an aluminum prop 13.5 x 15. Originally it was a two-toon and when I first got it my WOT was 28mph at 5800 rpm. I am not a toon cleaning nut, occasional wipe down on the sandbar maybe once a year, pressure washed and shark hide by marina every spring. Within a couple of years my WOT never exceeded 24 or 25 (cant remember for sure)

Added the express toon package a while ago and saw an increase in WOT to 31. Now that it has been a few years my WOT is again dropped to about 27.

In a couple of more years I will erase the first 1 on my 115 and go live in SemperFi's garage and join him on his lake
 
Yes, you can damage your engine by over or under revving (lugging) your engine. Like Carl said, the numbers you provide don't sound right. I'd start by determining what the WOT RPM suggested range is for your engine. You might also want to contact Ken at propgods.com for some advice. Good luck...


When you say "do not sound right" do you mean the pitch is off or do you think my tach is off? After calling around and giving the numbers most dealers are telling me to go with a 17p over the 19p. Thanks for the help!
 
When you say "do not sound right" do you mean the pitch is off or do you think my tach is off? After calling around and giving the numbers most dealers are telling me to go with a 17p over the 19p. Thanks for the help!
After rereading your post, let me try again. Not sure what your WOT recommended range is but 6400 seems way to high. That said, as you have experienced for yourself, a 1" change in pitch results in about a 200 RPM shift (up or down, depending on if you're decreasing or increasing the pitch). As such, going to a 17 or 19P will bring down your WOT RPM's and increase your speed. It'd be nice if you could try both out before making a decision, but if you have to choose I'd go with the 19P in hopes of getting your RPM within the manufacturer's specifications. Hope that helps...
 
It sounds like your tach is off to me. I can speak to experience on this as my tach would occasionally show 500+ RPM's high which is one of the reasons I replaced it with a multi-function gauge. WOT on a Yamaha 115 4 Stroke is 5000-6000 RPM's (assuming the motor is not a 2015 or newer) and you're seeing 6400-6800 (shouldn't a rev limiter kick in?) . Additionally, if you look at the performance bulletins for Bennington's running a 115 on Yamaha's website, you'll see that all but one are running 13 pitch SS props and that one is running a 12. I wouldn't think a 115 could swing a 19 pitch prop without seriously lugging. I personally have run 11 thru 15 pitch props on my 150 and only exceeded 6000 RPM's with the 11 pitch. Just my 2 cents for what it's worth. The performance bulletins are located here (you can sort by manufacturer and HP):

https://yamahaoutboards.com/en-us/home/owner-resources/all/performance-bulletins
 
Last edited:
I would tend to agree that your tach is not reading correctly. I had a 2250RL with a yamaha 115 and water glide center toon. That boat ran a 13.5 x 15 aluminum prop (slightly modified increase the cup) with a top speed of 32 (gps) at 5700 rpm's. I ran a painted stainless steel prop 13.5 x 16 with similar results. I still have the steel prop.
 
Back
Top