Years ago, I'd curse my CB550 when driving home in the rain, commute traffic, at night, since it would sputter and fire on few cylinders. While it was exciting, it wasn't fun. The ignition leads were less than 5 years old then, quite supple and all the rubber bits kept water away from what wasn't supposed to get wet.
One night after the ordeal, I still had enough energy, and determination, figure out what the F**K was going on since the effects often carried on to the next mornings commute for a short bit of time. Plus I found out that it didn't really need rain to cause problems. Driving through wet streets from broken sprinkler heads would also cause it to sputter. Well, I took off the points cover and low and behold water was in there. Dried it out and the problems immediately went away. Great. So, after a few more sputtering events and one near death event from a cage that I couldn't power away from, I finally went to the hardware store and bought some thin neoprene. Since even brand new cork gaskets that are normally put there, wouldn't seal out water, I thought I'd give neoprene a try. I made a gasket for it out of that neoprene. Well, it worked. Doesn't matter how wet the coils and ignition wires get, they all still light the cylinders when they're supposed to.
Problem solved... A nice side benefit is that it is reusable. That same gasket is still on the bike to this day. I do this upgrade to all my SOHC4s. Well worth the time & effort.
It may well work for you, too. Make a points cover gasket.
Cheers,
