The Yardman 12AV829C755 was a 21-inch, self-propelled push mower, produced by MTD mowers, of Cleveland, Ohio. The Yardman 12AV829C755 mower could be used as a bagger or as a mulching mower. It came equipped with a 6.5-horsepower Briggs and Stratton "Quantum" engine. Changing the oil on the Briggs and Stratton Quantum engine can be difficult for beginner mechanics, but is definitely a great afternoon project. The oil should be changed after the first five hours of use on a new Briggs and Stratton engine and every 50 hours after that.
Things You'll Need
- Old newspaper
- Drain pan
- 3.8-inch-drive ratchet with 3 inch extension
- Flat-head screwdriver (optional)
- Pliers (optional)
- 1-quart HD-30 motor oil
Start the lawnmower and let the engine to run for five minutes to allow the engine oil to warm up. Turn the engine off. Remove the spark plug wire from the spark plug. The spark plug is located on the front middle of the engine. Tilt the lawn mower upward, so that the air filter and spark plug are facing upward. Set a jack stand beneath the mower deck to stabilize the mower during this project.
Place newspapers and a drain pan beneath the deck and the engine. Insert a 3/8-inch-drive ratchet with a 3-inch extension onto the head of the drain plug on the bottom of the engine. Turn the drain plug counterclockwise to remove it. Allow the engine oil to drain for five to seven minutes. Install the oil drain plug and tighten it snug, using the ratchet and extension.
Remove the stand from beneath the mower deck, and lower the mower to its normal position. Remove the oil fill cap, which should have two prongs sticking up at the top. Use a flat-head screwdriver or pliers to loosen the cap if needed. Insert a funnel into the oil fill hole.
Add 1/2-quart of HD-30 motor oil to the fill hole to start. Check the oil level. Add oil in small amounts until the oil level shows full on the dipstick. Insert the oil fill cap and dipstick and tighten the cap snug by hand. Replace the spark plug wire back onto the plug. Wipe any spilled oil off of the mower deck and oil fill areas to avoid a potential fire hazard.
Tips & Warnings
- Upkeep on the Briggs and Stratton Quantum engine involves changing the oil every 50 hours and changing the spark plug every 100 hours. Change your air filter every 25 hours if it does not have a foam pre-cleaner. If the air filter has a foam pre-cleaner, change the filter every 100 hours, and the pre-cleaner every 25 hours. Divide the maintenance scheduled hours by the amount of time you spend mowing your yard. This equation will tell you exactly how many times you can mow your yard before needing to perform maintenance.
- Do not overfill the oil in the engine. Excess oil can create added pressure and cause premature oil leaks in the engine and from the external engine gaskets.