Im having problems with all four of my string trimmers (3 Kawasaki + 1 Stihl). Sometimes they are hard to start cold, and hard to start hot. Sometimes they will hardly keep running. I had the carb rebuilt on the Stihl last week, but its giving me a fit. The Kawasakis are still a few weeks less than a year old, but Im told that carb problems arent warranted, so Ive been thinking about taking the carbs apart myself. Are they that hard to clean? I started them all up today, let them run (they ran pretty good cold) and sprayed carb cleaner into the intake. They stumbled a bit then resumed normal RPM's. I didn't think this made much difference.