First pontoon

[Crimson seal]

Bought a used pontoon boat yesterday. It has a 2003 mercury EFI 125 on it. However the prop is a 12p.

Motor runs good until you get it wide open the it sounds like its cutting out

My question is that the wrong pitch for this motor. Everything I have read it should be a 17p or 19p, and is this what is causing it to sound like its cutting out?

Thanks for the help

 

[TurboM700]

Re: First pontoon

Will need to know what RPM you spinning at WOT. But yes a 12p seems to little and you are more then likely bouncing off the rev limiter of the motor. (not a good idea)

If i remember right 1p equally about 100rpm roughly.

 

[rogerwa]

Re: First pontoon

You are missing some key info.. What is the boat size/details? Also what the WOT RPM? Just for comparison, I run a 25' twin tube pontoon with a 115hp evinrude with a 13P prop. I am right at the appropriate WOT for my engine and get about 24mph.

The cutting out, without much idea,could be a fuel starving issue. Somewhere in the fuel flow there could be a restriction. Clogged vent, clogged pickup, collapsing hose, air leak, etc..

 

[lakegeorge]

Re: First pontoon

Bought a used pontoon boat yesterday. It has a 2003 mercury EFI 125 on it. However the prop is a 12p.

Motor runs good until you get it wide open the it sounds like its cutting out

My question is that the wrong pitch for this motor. Everything I have read it should be a 17p or 19p, and is this what is causing it to sound like its cutting out?

Thanks for the help

Go to the Mercury Marine web site and type in engine test and you will find the Merc 115 and all the different boats that this motor was tested on.
It will also show the props that were used and a lot of other info.

 

[WaterDR]

Re: First pontoon

That really sounds like the wrong prop

 

[cc350]

Re: First pontoon

13p should be close. Check wot rpms

 

[Jeep Man]

Re: First pontoon

3 blade or 4 blade? A 13p sounds about right but if is a 4 blade, typically you would drop the pitch by 1. RPMs are king. If you are running at the recommended max. RPMs at wide open throttle then your pitch is correct. Each single increment change in pitch will create a change of 300-400 in RPMs.