Usually, the oil cap is screwed on; to unscrew it, turn it counter-clockwise.
As of July 2014, the market cap for Briggs & Stratton Corporation (BGG) is $885,891,230.16.
On the bottom of the mower, it takes 3/8" socket driver (no socket) to remove it
i just take the cap off and tip them to the side into a drain pan, most of them have a plug on the bottom, but easier through the fill tube
The way to drain gasoline from a Briggs and Stratton lawn mower is to take the oil cap off and drain the oil. From there, run a rubber hose into the drain and siphon the rest of the oil and gas out.
It is very simple... On the side cover, near the clutch, is a plastic cap. Remove that cap. This is the oil fill cap. You may need a small screwdriver for a lever. Then on the front of the engine is a square headed plug. If I remember correctly a 3/8" open end wrench will fit it. Remove this plug, be sure not to lose it. After the oil is finished draining, reinstall the plug and then fill with oil. Depending on the application it should have anywhere from 14oz to having the oil dribble out of the fill hole.
fill tank, to top of neck, watch the leak area, [don,t start it]
Three specs are considered critical; the connecting rod cap at 110 in-lbs, the sump cover at 110 in-lbs and the cylinder head at 165 in-lbs.
Remove the radiator cap ONLY when the engine is cold.
Under the hood on the passenger side of engine compartment. Be sure the engine is cold when you remove the cap.
Remove the radiator cap when the engine is cool and add the coolant into the radiator or you can add to the coolant overflow bottle. DON'T remove the radiator cap when the engine is hot!!!
when the engine is cold push down on the cap and turn left
Briggs Stratton Oil ChangeI changed the oil on 7 Briggs engines today, and my shop is a Briggs service agents.1) take HT cap off, and make sure it cant move back (a spark can jump)2) turn machine on its side carb upper most.3) put a little container under the oil filler/dipstick. (a 3.5 hp engine has under a pint in it).4) unscrew filler cap/dipstick and leave till completely drained.5) when finished upright machine and refill with the right oil, (most Briggs engines use SAE30, its a thin oil because there is no oil pump on these small engines, they have a splashier on the big-end) replace dipstick, HT cap and start.6) bobs your uncle. :)