Dave,

I am glad you have had good sucess with what you have been doing. All of the things listed can and does occur in four strokes. The largest service centers biggest issue is the de-coking of motors returned for service. Like you I have been doin this for a while, around thirty years, and I have seen a few gummed up engines. Granted, not everyone experiences these problems, mainly due to experience in setting up a motor properly and not over leaning the motor. Since we manufacture for the many and not just the few we recommend what we know works the best in this application.

Jerry