Merc 125 prop redline HELP

[dieseldave24v]

Hello,
I have been out of the boating world for a few years now. I bought a new to me boat last week. I think it has the wrong size prop on it, but want to make sure before I buy another one.

Boat 2002 sea hunt 200 triton 20' 4" open fisherman CC
Motor 2002 Merc 125 saltwater
Prop 13-1/4 x 17 pitch SS 3 blade

The motor is electronically limited "rev limiter" to 5250 RPM. This seems very low to me, I am used to 6000 RPM, but I have verified throught the service manual that this is correct. My issue with the prop is that when I do a hole shot the boat take off and planes instantly. This boat is a rocket to about 28 Knots. Then if I leave it wide open it will bounce of the rev limiter. I dont know how much RPM it would turn without the limiter. I was thinking of putting a 19" pitch prop on it. I dont pull skiers or anything like that, but I want more top end and I dont want the motor to redline.

 

[dieseldave24v]

Re: Merc 125 prop redline HELP

I didnt get a responce so I gambled...was very nervious on the way home. Long story short I went up to a 19" pitch SS 3 blade....What a difference. I gained 9 MPH and the boat still planes quickly.

 

[Irv964]

Re: Merc 125 prop redline HELP

I didnt get a responce so I gambled...was very nervious on the way home. Long story short I went up to a 19" pitch SS 3 blade....What a difference. I gained 9 MPH and the boat still planes quickly.

Good call for you, it sounds like you made the right choice with your new prop. 9mph is a great increase! I bet your thinking about a 20 or 21P now
What is your max rpm with the 19? Can you still hit the rev limiter?........Irv964

 

[dieseldave24v]

Re: Merc 125 prop redline HELP

With the 19 I am on the high side of the operating range, but dont hit the rev limiter. I think a 21 would work, but I wont try one unless its free. I am happy with it now. Enough gambling for me