under the deck, on the base of the engine
Takes a 3/8's ratchet inserted into the square hole to remove... or tilt on it's side & drain out the oil filler tube
model type and code of the mower and from the engine. generally it is metal stamped on the engine and the unit model is near the rear of the mower.
I believe it a engine on the back with valves
There is no oil drain on a 650 series lawn mower. You have to turn the mower over and drain the oil from the spout you put it in the engine. Make sure the gas tank is empty
To properly drain lawn mower oil, first, warm up the engine by running it for a few minutes. Then, locate the oil drain plug underneath the mower and place a container underneath to catch the oil. Remove the drain plug and let the oil drain completely. Once drained, replace the drain plug and refill the mower with the recommended amount of new oil.
Drain out the excess. Too much oil will damage the engine.
To properly drain oil from a lawn mower, first, make sure the engine is cool. Locate the oil drain plug underneath the mower and place a container underneath to catch the oil. Remove the drain plug and let the oil drain completely. Replace the drain plug securely and refill the mower with the recommended type and amount of oil.
You can find the operator's manual for that engine at www.briggsandstratton.com. You will need to contact the manufacturer of the mower for the lawn mower owner's manual. Briggs and Stratton did not amke that mower, only the engine.
The Briggs and Straton Quattro is a 4 HP
need the engine model, type and code
Buy a lawn mower engine repair manual at Border's or Barnes & Noble.
drain it
Go to a small engine dealer or repair shop .