... -2,SGS certificate 4.Strong engine 5.2-stroke,1-cylinder backpack brush cutter 1, two stroke engine fuel (# 90 above), oil, sae30 ... use.7, the gasoline engine running 100-300 hours, should remove carbon once. When clearing off of cylinder head, clear the cylinders ... and the valve seat.8, keep the gasoline engine cylinder especially heat sink clean.9, come on, inspection, maintenance, repair, ...