1958 Johnson seahorse Prop Pin

[Cresliner2012]

Have just bought a small 16 foot alum crestliner. The out board is an old Johnson seahorse have change a lot of parts. When changing the impeller I noticed my prop pin was broken. Their is this loud clank when running at idle speeds could his pin be he problem. Running any faster and the noise becomes no more.

 

[Barnacle_Bill]

Re: 1958 Johnson seahorse Prop Pin

That is called a shear pin. It may be slipping. I know some people have made them from drill bits or you can try sea-way.com in Seattle, Washington

 

[Texasmark]

Re: 1958 Johnson seahorse Prop Pin

I have learned on this site that they are really referred to as "drive pins"....well pfooooo on that......Just like after 50+ years of boating, I find out that the plate over the prop is not an "anti-cavitation" as it was referred to back then, but more correctly (and true) a anti-ventilation plate.

Back when I ran the breed they were shear pins.....every time you needed your OMC/Scott Atwater engine to get you out of a tight, the prop would hit something and you would loose your propulsion because the "drive pin" would shear. In small engines it was made of Bronze or plain brass usually. On larger engines (whopping 35 hp at the time), it was SS. The props came with a rubber cushion hub that absorbed a lot of impact and if really bad the hub would break loose and allow the prop to absorb the impact with the obstruction while the engine/gear train continued to turn.

Mark