This is the 5th set of Yamaha coils (4 XJ sets and this MaximX set) I have repaired this way. I have tested a set (engine running) with the full force of a pressure washer. I highly recommend this to anyone who is having problems in wet weather. Net cost is about CDN$10 per set -- 30 if you buy new NGK resistor caps too. Compare that to the cost of a new set of coils!
Reference should be made to: The XS1100 wire replacement guide before doing this work. This article deals with the differences between the XS/XJ coil and the ones used on the MaximX.
I stayed with the copper-core type wire used originally. I have no problem getting it for a reasonable price, and suggest anyone who can't get it at their local auto parts store could try a small engine repair shop or marina. The wire is fed in and pushed and twisted fully over the pins so they make good contact with the conductor inside the wire.
Next, 5 minute liquid epoxy is mixed and poured into the windows. I twirled the wire around at least two revolutions to make sure it was fully distributed to seal against water entry. A small air bubble is still visible in the epoxy in the upper window.
I then mixed some epoxy putty to build the case back up to the original profile. This is more for mechanical strength and protection than anything. I figure "Hey, Yamaha wouldn't make it that thick in the first place if there wasn't a reason."
Finally, I finish it off with two coats of Plasti-dip rubberized coating. I taped the ends of the steel cores and folded the primary leads up along the new ignition wires first. The whole coil is small enough to just dip right in the can past the entrance of the new wires. The coil is slowly withdrawn (over about a minute) as per the directions on the can, and then it's hung up to set for an hour or two. Once dry, it dipped it again to make sure.