The stihl 4 mix stuff I never adjust the valves the stuff runs good for years of heavy use which is why I like the brand. When I had the shin 4 mix trimmers they were each at the dealers half a dozen times that year. I didn't just run away I ran away from that stuff screaming. The shin 2 cycle is way better than their 4 mix but still lacks the endurance I demand in a handheld piece of equipment.
yes, the 2-cycle shin is the best! I hope to get out to the dealer soon to look at the machines