outboard runs but will not run faster than idle speed

[bigmen905]

I have a 1979 Johnson 25hp outboard. I took my boat on a fishing trip, it started out fine but after a few days the engine would rev up but the fastest my boat would go was idle speed. After I got past 1/4 throttle the engine would continue to gain speed but the boat would not. What kind of problems should I look for and are they going to be worth fixing?

 

[NathanY]

Re: outboard runs but will not run faster than idle speed

Sounds like a spun prop hub.

 

[bigmen905]

Re: outboard runs but will not run faster than idle speed

The shear pin was not broke. Do you think a lower unit problem?

 

[St. Bennett]

Re: outboard runs but will not run faster than idle speed

Did you take the shear pin all the way out? Sometimes th pin can shear off in more than one spot. If this happens then what could be happening is the shear pin looks fine but there is no middle to it. Centrifugal force can alter this.

 

[bigmen905]

Re: outboard runs but will not run faster than idle speed

I removed the shear pin and it was still solid. I then replaced it and had the same problem.

 

[Walker]

Re: outboard runs but will not run faster than idle speed

1979 would have a rubber hubbed prop. I agree the hub is spun. Need to have it re-hubbed at a prop shop.

 

[bigmen905]

Re: outboard runs but will not run faster than idle speed

How much do you think it should cost to have this done? What do you think the normal shop rate should be I have had some questions about how much the dealer has charged me in the past.

 

[roscoe]

Re: outboard runs but will not run faster than idle speed

About $40. <br />Do you have a spare prop? If not now is the time to buy one. Then you can use it until your prop is fixed.