Abstract: A four-stroke internal combustion engine is provided that is capable of use in many power tools, including those power tools subjected to tippable applications. There is provided within an engine housing, an oil reservoir and a valve chamber which independently communicate with a crank chamber. A system of strategically placed dividers and passageways within the engine housing appropriately directs lubricant within the engine housing so that the internal cavity of the engine is lubricated during use in any operational attitude, and so that the lubricant flows to and is held in the proper chambers during storage. There is also provided a breather arrangement for an internal combustion engine which includes a camshaft having a hollow passageway in communication with a crank chamber.

Abstract: A four-stroke internal combustion engine is provided that is capable of use in many power tools, including those power tools subjected to tippable applications. There is provided within an engine housing an oil reservoir and a valve chamber which independently communicate with a crank chamber. A strategically placed divider and passageway, located within the engine housing, appropriately direct lubricant within the engine housing so that the internal cavity of the engine is lubricated during use in various operating attitudes, and so that the fluid flows to and is held in the proper chambers of the engine housing during storage. There is also provided a breather arrangement for an internal combustion engine which includes a cam shaft having a hollow passageway in communication with the crank chamber and the air intake system of the engine.