Push mowers have long been the go-to machine for mowing yards and small- to medium-sized lots. Many are self-propelled, easy starters--taking almost all the work out of mowing. One feature that enables today's push mowers to start more readily than in years past is the ability to prime the carburetor with gas. What once took several cord pulls and a sore arm to light off the mower is now routinely accomplished with a single pull.
Check the gas tank for proper fill of gasoline. Use only fresh gas when refilling the gas tank in order to prevent stale gas from gumming up the fuel system. Also, use caution when filling the tank; do not overfill and allow gas to flow out on to the ground.
Remove the oil fill/check dip stick and inspect the condition and level of the oil. Running low on gasoline will not ruin a lawn mower engine, but running low of oil certainly will. If the oil level is below the "full" mark on the dip stick, add just enough new oil to bring it within range. Like the gasoline, do not overfill with oil. Doing so will cause excessive pressure to buildup in the engine crank case, a result in engine damage.
Position the mower in an area with either short grass, or no grass, before attempting to start it. The blades begin to rotate on a push mower as soon as the engine begins to turn; tall grass will create resistance against the blade--creating resistance in the engine--making it hard to start.
Pump the primer bulb four to five times, or until it begins to feel firm. Do not pump it more than this; too much gas will flood the carburetor.
Move the blade control handle next to the push mower handle and grasp both with one hand. Grab the starter rope with the other hand and pull it out slightly until you feel resistance in the rope.
Pull the rope with an aggressive, full stroke of your arm while maintaining control of the mower and blade control lever with the other hand. When the engine starts, allow the rope to gradually return to its normal position. Do not allow the rope to snap back.