For those of us who use outboards for or around our boats, the reliability of modern models is so good that it's almost feels natural that they will run successfully forever. As engines they may seem to do so but the external world sometimes reaches out and makes itself known quite unexpectedly - like the outboard engine propeller hitting an unknown or unseen solid object underwater.
Or, with things mechanical, the loading of the propeller, through the shear pin, may gradually find a weakness in the pin material, leading to an unexpected fracture. Result in both cases - lots of sound and no motion; "disaster"!
Now it really doesn't have to be like that; there is a list of essential spares for your boat and it's equipment and a shear pins are one them. Paradoxically they are cheap to buy yet have really high use value and may be reasonably considered an item of safety equipment when weighed against a bad sea and no propulsion.
When replacing a shear pin, there are a few simple actions you can take to ensure the best result. Firstly, as part of your pre-season maintenance programme, prevent a future stress fracture by ensuring the shear pin hole in the propeller shaft has no sharp edges at the hole edge; the simplest way to remove any burrs is to use a round needle file and patiently work around the hole at both ends to create a small radius on the hole edge circumference; with tools to hand this should only take 15 minutes to complete; and secondly, replace the propeller retaining nut lock split pin (if one is used); every time a split pin is bent over, it's metal is subjected to loads that can lead to a stress fracture failure over time.
Or, with things mechanical, the loading of the propeller, through the shear pin, may gradually find a weakness in the pin material, leading to an unexpected fracture. Result in both cases - lots of sound and no motion; "disaster"!
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| Holt Outboard Motor Shear Pin-Blister-Pack |
When replacing a shear pin, there are a few simple actions you can take to ensure the best result. Firstly, as part of your pre-season maintenance programme, prevent a future stress fracture by ensuring the shear pin hole in the propeller shaft has no sharp edges at the hole edge; the simplest way to remove any burrs is to use a round needle file and patiently work around the hole at both ends to create a small radius on the hole edge circumference; with tools to hand this should only take 15 minutes to complete; and secondly, replace the propeller retaining nut lock split pin (if one is used); every time a split pin is bent over, it's metal is subjected to loads that can lead to a stress fracture failure over time.
So don't delay if this blog reminds you to stock up; Holt Marine Pre-Pack / MPP aftermarket shear pins are available for a number of popular outboards that includes these brands and models (2 per pack): Suzuki, 2 HP, 4 HP; Tohatsu, M4, M4A, M5, M5A; Tohatsu, M8, M8A, M9.8, M9.8A, M12, M12A; Yamaha Mariner, 2 HP, 6 HP, 20 HP, 25 HP; Johnson/Evinrude/OMC, 2 HP, 4 HP, 20 HP, 25 HP, 40 HP.
May your days out be sheer joy.
May your days out be sheer joy.
