I'm throwing this out there with the understanding that I have never taken a starter apart and therefore have no idea how it looks inside. With that said, MG Chemicals makes a conformal coating that can be applied to electronics, or any electrical connection, and make it waterproof. I wonder if something like that would work? I've used it on hobby electronics and it works like a charm. Stinks to high hell but works well. The link below is what I used but they have many different products.
422B is a 1-part, acrylic-silicone blend conformal coating that cures to a durable, flexible and smooth finish. It is easy to apply and can be handled in only 8 minutes. It may be removed with appropriate strippers, or soldered through for repair or rework.
www.mgchemicals.com