I have an MS 260pro that i use for cutting wood for home use. Last time out saw starts idles fine. After it warms up it wants to stall at full throttle. Replaced air and fuel filter and gas line, exhaust is clear, vent is clear. Using ethanol free 92 gas. , first time I took it out this year it ran fine, now...............tear carb apart and clean/rebuild ????? or send it to the shop? thanks for advice