I tried shrink wrap once on some Chinese coils but then the coils wouldn’t fit into the mag plate. Instead of grinding out the mag plate, I just cut it off. Since I’m a fair weather sailor these days and my motors only get used on nice days, the mags don’t get wet or damp. The original boots might have helped to hold the wire in the coil but since the replacement coils have threaded pins and 7mm wire fits quite snug with some silicone grease on them, I don’t really think boots are really necessary.
