1969 20hp Johnson sea horse high revs with no propulsion when accelerating

[jeffbergmanmusic]

Hi all thank you in advance for the comments. I purchased a “restored” 1969 20hp Johnson sea horse and it idles and runs at low rpms in both forward and reverse but when I accelerate the boat loses propulsion and the motor high revs. It does this is both forward and reverse. I have seen a lot about prop bushings and such but on a 69 sea horse the prop has no bushing it’s screws on with a cap and locks in place. Would love some insight on what could be the issue.

 

[racerone]

Well ----It does have a rubber bushing !------So try another prop.

 

[kbait]

Prop hub bushing is shot. Replace prop and you’re good. New available right here at iboats: https://boatpropellers.iboats.com/J...llers/?chart=8&engine_id=29&cart_id=000000000

 

[tphoyt]

In most cases it’s very hard to spin a prop with a shot hub by hand.
Thats why it’s only slipping at high rpms.

 

[F_R]

Similar to this one

 

[racerone]

I used to keep a prop with a section cut out to show those " newbies " that there are rubber hubs in props.

 

[jeffbergmanmusic]

Prop ordered