I have a '78 KZ1000 A-2 with dyna-s ingnition and coils. The bike runs great for the first 1/2 hour (a little less on a hot day) and I can make dozens of full throttle runs, generally 1st thru 3rd gear. After about a 1/2 hour, I'll be wide open in 3rd and I'll loose a couple of cylinders. I can make them fire on all four adjusting the enriching circuit to match rpm and load until I get home. Once cooled down it will run great again. I think I may have a coil going bad. I have replaced the plug wires, plugs and the dyna-s unit thus far. any thoughts before I buy new coils?