I ran into a guy today who has been into R/C boat engines for many years. I have not seen him since the '80s, but he is a good engine man. He told me that part of my problems were due to using Klotz Two Stroke oil. I usually pick up several quarts of Klotz, at the Toledo show every year. I have never had a oroblem before. I mixed this up a few weeks ago. I have a 3W60k and use the same gas. I bought some Amsoil as many Giant scalers use that.