... heat engine oil changed rear can normal use. Normal use accumulative total work 30 hours or so ... state stop.4, oil, want to use correct types, are factory product, clean, gasoline to clean, fresh.5, non- ... filter with soap and water dry cleaning after use.7, the gasoline engine running 100-300 hours ... clean.9, come on, inspection, maintenance, repair, want to pull out spark plug hat, don't smoke, away ...