I had problems with weak spark with my GT550 a few years ago, when a friend of mine reommended replacing stock condensers with ones from a Ford 390 V8 truck engine. Really! I know it sounds strange. Bought them at NAPA, any year will do.Cheap too,less that $15. Wired them up under the gastank next to the coils. Been 4 years since-no more problems. Maybe this would work for you.