By following these
simple steps you can bring your lawn mower's engine
back to life and keep your mower running stronger, longer.
Begin by starting the engine on your lawn mower and running it until warm
and the fuel tank is empty.
Disconnect the spark plug wire to prevent the lawn mower from starting
Change the Oil
Clean around the oil fill and remove the dipstick. Depending on your
type of machine, the oil may be drained by removing an Oil Drain Plug located under the
mower housing just above the blade. To get to it, put your lawn mower up on a couple of
cinderblocks. Then, with a basin to catch the used oil, remove the plug and allow the oil
to drain until it stops dripping out of the mower.
Put the Oil Drain Plug back in then refill the engine with oil. Use
the Oil Dip Stick as a guide and only add oil up to the "Full" mark on the
dipstick. Oil capacity is approximately 20 ounces on most lawnmower engines.
Change the Spark Plug
Take the lawn mower off the blocks and remove the spark plug. Before
check its gap (refer to your owners manual for specifications),
most Briggs & Stratton engines require a spark plug gap of 0.030" or 0.75mm.
After checking the gap, screw the new spark plug in finger tight then tighten 1/4 to 1/3
turn more with your socket, but do not put the spark plug wire back on just yet!
Replace the Air Filter
Now you may take out the old air filter and replace it with the new
one. A new high efficiency air filter helps your lawn mower's engine perform at its
peak. Be sure to saturate new foam filters with fresh engine oil, wrap in a clean
cloth, and squeeze to remove the excess oil before installing. If you have a Cartridge air
filter (as illustrated, right), skip this step.
Check and Replace the Blade
If your lawn mower blade is chipped, dented, bent, cracked or dull now is
an excellent time to replace it.
A study at the University
of Nebraska proves that gas-powered mowers with sharp blades use roughly
20-percent less fuel than mowers with dull blades. Plus, sharp blades
slice grass tips cleanly so your lawn looks better and is less susceptible
Be sure the Spark Plug Wire is disconnected then tip your lawn mower on
Use a piece of wood to block the blade and keep it from rotating while you
work to remove it. An old blade may have jagged edges that can cut you if you are
not careful so be sure to wear gloves when handling it to protect your hands. It also
would be a good idea to keep the gloves on when handling the new blade since it definitely
will be sharp.
Remove the bolt that holds the old blade. Mount the new blade with
the curved edges toward the housing. If the blade is installed wrong it will not cut
correctly and may cause an accident.
Fasten the new blade using the original washers and bolt. Tighten the bolt
that holds the blade to a torque of 60 ft-lb / 82 N-m (set your torque wrench to
then tightened the bolt one click. Do not click it again as you eventually will ruin
your torque wrench if you continue to give "just one more click to be sure").
Check the torque settings in your owner's manual to be sure of the
correct tightness and always position the curved ends of the blade to
point toward the lawn mower housing.
What You Will Need
SAE 30 Motor Oil Formulated for Lawnmowers
Container to Catch the Used Oil
New High Efficiency Air Filter
New Correct Range Spark Plug for Easy Starting
Gasoline Additive Formulated for Lawn Mower Engines
Standard or Phillips Head Screw Driver
Spark Plug Feeler Gauge
New Lawn Mower Blade
Disconnect the Spark Plug Wire to Prevent
Put the Mower on Blocks or Whatever You
Have Handy to Drain the Oil From it
This Briggs & Stratton Engine Requires
a Socket Extension to Remove the Oil Drain Plug
Use a Spark Plug Feeler Gauge or Gap Tool
to Set the Spark Plug Gap to Your Engine's Specifications
Open the Air Filter Compartment to Install
the New Filter
A Dirty Air Filter Makes it Hard for Your
Lawn Mower to Perform its Best
Tools for Installing a New Blade
Block the Blade to Keep it From Rotating
as You Remove it
BE SURE to always keep the bolt
that holds the blade tight! A loose bolt or blade will surely cause an accident.
Eleven Lawn Mower Care Tips