Propper Prop??

[drewmitch44]

I have a 1986, 115 yamaha 2 stroke. Im wondering what the propper size and pitch prop is for this motor. Im using it on a sea ray srv180. Im just wondering what i have on there now and if there is a way to tell what is on there now? I top off too fast. I could over rev the motor if i wanted too. I realize its a pretty small boat for a 115 but the max recomended is a 125. I get about 39-42 mph at 5500 rpm. I feel like that is about 3/4 throttle if you know what i mean. I took it up to 6000 and it still wanted to give more. Its not a hub slipping. And im not trying to go 300 mph i just want to select the right prop to get me to about 5500 rpm at wot and not a lot higher like i have now. I could over-rev the motor if i wanted too and it still speeds up at these rpm so i dont think its slipping. There is a white aluminum prop on there now. Thanks!!

 

[bowhuntrrl]

Re: Propper Prop??

Sounds like you need to go up 1 pitch. Any good prop repair shop should be able to tell you what pitch the prop is if there are no numbers on it. General rule of thumb is that you will drop around 200-300 rpm for each number pitch that you go up. A cupped prop will also drop more rpms.

 

[drewmitch44]

Re: Propper Prop??

ok i took it off and it says on the inner hub " 13 X 19-T". Is that a 13' prop and 19 pitch? Thanks!

 

[drewmitch44]

Re: Propper Prop??

13" not 13 foot. you know what i mean!

 

[jddenham]

Re: Propper Prop??

I'm assuming that you're testing with a light load?

I would hang on to the 19" for times when you might be pulling skiers or hauling several adults.

If you want better performance for lighter loads, a 21" aluminum, or 20" cupped SS prop would do pretty well for you.