Ignition wires

[steplift20]

I made the mistake of replacing the original wires with a set from a company called magstar, I thought it would be good since they were old , I should have left them alone. I was at my boat yesterday and was checking for spark and when I disconnected one wire at a time I noticed that the spark was jumping at the boot by the power pack and I don't know why that was happening the sires look good but why was it raking from the bottom? Can I coat the wires with something to fix it? I was checking for spark cause the last time I was out my motor coming back ran very bad like on only three cylinders do I checked but when I started her she ran great no issues so I am thinking it is a power pack going bad.