1984 Johnson 35 HP Top End Speed Problem

[111torrance111]

I have a 1984 Johnosn 35 HP motor that runs great from idle to mid speeds, but when I run at higher speeds it feels like the prop is slipping.

The motor sounds like the RPM rise but then I lose a little power.

How can I determine if this is a prop issue or a lower unit issue?

Thanks for any help you might give.

Jerry

 

[Max Thrasher]

Re: 1984 Johnson 35 HP Top End Speed Problem

I have a 1984 Johnosn 35 HP motor that runs great from idle to mid speeds, but when I run at higher speeds it feels like the prop is slipping.

The motor sounds like the RPM rise but then I lose a little power.

How can I determine if this is a prop issue or a lower unit issue?

Thanks for any help you might give.

Jerry

There is a piece of rubber inbetween the hub and the prop itself. It might have spun on ya. New hubs can be pressed in but I don't know how much.

 

[tashasdaddy]

Re: 1984 Johnson 35 HP Top End Speed Problem

props are built with 2 metal hubs, with a rubber bushing in between these will dry out, wear out. thus the slipping. permanent marker, draw a line across the prop hubs, take for a spin, if still lines are still lined up, it's not the prop. a prop shop can refurbish the prop.

 

[F_R]

Re: 1984 Johnson 35 HP Top End Speed Problem

If it is a lower unit problem, you will know it by the terrible grinding noise that can't be ignored. Smooth slipping is a spun prop or cavitation/ventilation.