5100 rpms?

[RLT III]

I have a 3cyl merc 50 with a 10 3/8*R13MWI prop is that amount right

 

[steelespike]

Re: 5100 rpms?

We need more info to tell for sure where you are at.Depending on the year of the motor it is rated at 5,300 to 5,800 rpm.Usually suggested to prop near the top of the rpm range.Without your boat info with your rpm and speed its difficult to evaluate your prop selection.If you read the stickies at the top of the page and on the prop store page it should help you understand prop selection a little better.

 

[RLT III]

Re: 5100 rpms?

well i just rebuilt fuel pump so that should change and explain the lower rpm's

 

[steelespike]

Re: 5100 rpms?

Yes it could.Was the 5,100 rpm a new developement? Don't keep your boat info a secret.Do you have any top speed info?How is the hole shot?

 

[Silvertip]

Re: 5100 rpms?

You gave us no data to help determine the correct prop. That said -- while there is no such thing as a standard prop, the prop you have is the one most often installed on that engine for boats in the 15 - 17 foot range. Several things you need to consider before you even think about changing props. 1) is the motor in tip top shape and delivering full power, 2) is the engine height (not trim) set properly. That alone can gain a couple hundred or more rpm. The AV plate on the motor should be at least an inch above the bottom of the boat as a starting point. 3) what load do you "typically" carry in the boat. A heavy load most of the time requires a prop with less pitch than if you typically run with a lighter load.
4) is your current prop damaged (bent or nicked up). 5) is the throttle opening fully. After verifying these items then make several full throttle runs with what you consider an average load and note the speed and maximum observed RPM. Post back with the numbers and we can go from there. Speed is best recorded using a GPS.

 

[RLT III]

Re: 5100 rpms?

I'm taking boat out this wknd and just fired up after putting new seal in lower unit and as you know I put a new fuel pump in it but my tach was reading 1800 at idle close to 2000 but it did not sound the high
Maybe the previous owner had turned the idle up due to the pump going but scared to adjust it if the tach is possible screwing up before pump issue it would idle at 800 all of this on muffs