... ,2.5HP gasoline engine,,starters:Manual ,high quality with best price generator engine ModelJF152FTypeForced-air-cooled,four stroke single cylinder,Valve ... crankshaft rotation. For inhalation of fresh gases and emissions, with intake valve and exhaust door. Pistons top center most ... stroke, the intake valve open, exhaust closed door. With the Pistons only points from the previous stop point downward ...