For a long term quality alternative for creating a waterproof gasket check it out.
duluthcycle.com
Motorized Bicycle Waterproof Silicone Magneto Gasket
MOTORIZED BICYCLE WATERPROOF SILICONE MAGNETO GASKET Finally a good solution to replace your cardboard magneto gasket with. Our high temp black magneto gasket compresses in between your rough case cover for a completely waterproof seal. Cardboard gaskets are worthless and will never keep your...
duluthcycle.com
