Have a 35hp, 1976, 357hk which has to cracked coils. I assume this is causing surges while at full throttle. It idles at the dock then after running for a while and shutting it off it becomes hard starting and runs like crap. Where can i find coils or are there universal coils that may be used such as motorcycle coils? And what else may be the problem. Carb has been rebuilt, fuel pump gone over, and points adjusted. Need help?