RE: YS 160 DZ
No nothing will fall out. Just lay the engine on its side and remove the 2 screws on the cam cover. There is no gasket, the cam cover is sealed by an O Ring. Just ease the cam cover off and lay it on a clean paper towel or something dust free. It takes about a tablespoon of oil to fill the chamber. I used a turkey basting syringe. Fill it until the gear is just submerged then stop and put the cover back on. Thats how I was instructed to do it. I havent run the engine yet, but that was the procedure for oiling the cam.