Professional-use equipment takes a beating.String trimmers,mowers,backpack blowers and other equipment can run continuously in hot,wet and dirty conditions for months straight. Using low quality oil makes the situation worse. Two-Stroke oil that fails to protect against carbon causes stuck piston rings,clogged exhaust ports and plugged spark-arrestor screens. Stuck rings leads compression loss, while heavy carbon chokes off airflow.Workers in the field are left with hard-starting, poorly running equipment that lacks the power to get the job don right.