Logo
FULL SITE MENU

'59 35 HP Problem.

T

troyr

New member
First timer here, I have a 1959 Johnson Seahorse 35 HP.It starts fine, idles fine, goes into gear fine, and pulls fine at low RPM. The problem is when I increase the throttle it's like someone pushes in a clutch. The rpm just starts getting higher and the prop stops spinning, all the while the levers remain in gear, but it's not "in gear".then I slow the throttle way down then it kicks into gear.No matter how slow I try to increase the speed it does the same thing. I don't know much about outboard motors but I'm willing to jump in and try anything.Any help would be appreciated. Troy in Wa.
 
(Propeller Hub Slipping)
(J. Reeves)

A propeller consists of three parts, the outer portion being the propeller itself, a hub that is either splined to the propshaft or has a drive pin securing it to the propshaft, and a rubber vaulcanizing component between the propeller and the hub similiar to a automotive motor mount.

When the vaulcanized rubber fails, the result is that the propeller sufferers what is called a slipping hub. You can test two ways to see if this is the problem.

1 - Mark the propeller and the hub with magic marker or whatever so that the marks are in one line. Test run the boat, then observe the marks. If the marks are no longer in line, the hub has slipped.

2 - Remove the spark plugs. Put the engine in gear. Block the propeller with a piece of wood. using a socket and a good length beaker bar, attempt to turn the flywheel in a clockwise (normal) direction. If you can turn the flywheel and see the propshaft turn within the propeller, the hub has slipped.

The cure is to either have the propeller rehubbed at a reliable propeller repair shop or replace the propeller.
 
Had the same thing happen to my 18 Evinrude. Prop needed a new rubber hub. As Joe says, either get a new prop, or get it re-hubbed. Depending on the shape of your prop (nicks, dings, bent blades), if you get it rehubbed, you might need to have the blades re-built too.
 
I'm having a hard time trying to figure out where any rubber is. All I can see is an end cap, cotter pin,shear pin, and the prop.it is disassembled the shaft is smooth with a hole where the shear pin goes
 
I'm sure that you see the bronze hub, then the alumium propeller. The vaulcanized rubber is between them and cannot be seen under normal circumstances.
 
I understand-----------------Had to take a hacksaw to one of those props to show the disbelievers that indeed it has a rubber slipclutch.
 
Back
Top