Thread: '56 Evinrude Lightwin, prop shear pin ?

Hello, I have a 1956 Evininrude 3 hp Lightwin motor. Hit a rock and broke the shear/drive pin. The pin was 1/8" solid steel . I replaced it with a 1/8" roll pin. Someone told me to use a brass pin instead beacuase the hardend roll pin would cause damage.. My question is will the brass shear to easily makeing me replace it with every bump of a stick ot graze of a stump ? Or will the roll pin be to hard and cause damage to the prop or shaft ? Since it had a solid steel pin it seems a roll pin would be weaker and break easier than the original steel pin yet hold up better and longer than brass. I also have 1/8" mild steel rod that is softer, but is harder and tougher than brass, would that be a better compromise ? Any advice or input ? -Thanks

I wouldn't run a roll pin, too hard. Might break a prop instead. Brass was for real stumpy or rocky areas, as I was told. Steel gave a bit more strength but was still pretty soft, as steel goes. I'd carry both, and put the one that you sheared back in it til you know more. Super little motor. I had a 67, sold it to an old gent I worked with. I used a brass in an older 35 or 40 I used to have, and the torque of the motor sheared the pin. Just my past exp, I'm no tech.

Rolled pins are made from hardened steel. They are designed to resist breaking. No doubt the roll pin is stronger than your gear steel. You will break something else brfore the pin shears.

Steel- pretty generaic definition. There are numerous ways to make steel and each of them offers a different level of strength. I wouldn't use any old piece of steel.

Brass- by far teh best way to go, an no doubt what came from the factory. I have a '57 Johnson 18hp Seahorse motor that uses a brass shear pin. I have hit two stumps in as many years, both times teh pin sheared and saved the rest of the motor. I carry a few replacements, and a long nose pliers. My local Marine stocks them. I pick up a package of two for a couple of bucks. Worth every penny.

My reference to steel was to sheer pins made of steel. Same dimensions and made of soft enough steel to sheer when needed. Sorry if I didn't give enough detail. Both were on the same rack at my dealer at the time.

Not a problem Skeetbum. Love the name by the way. I too appologize, my refference to generic steel was also incomplete.
It wasn't until I started working in a pattern making/machine shop that I learned there is a hugh difference from one piece of steel to another piece of steel. The art of pouring molten metal down a black hole to produce something has been around for a long time, centuries. However recently man discovered that by mixing various chemicals and various metals you can create all sorts of steel suited to do all sorts of things. Using steel is fine, provided it was produced for your intended purpose, in this case to shear and save your lower unit.

When I was in highschool I used to help a buddy of mine fix lawnmowers in his dads shop. The shear pins were all made out of aluminum because it was cheaper/easier to replace a shearpin than to fix/replace gears/bent shafts..etc.