Definitely one of the most widely shared problems and one of the most frequent reasons for post purchase phone calls to lawn mower suppliers. There are a number of common reasons.
1. Recoil chord: Sometimes people buy a recoil-start model without working out if they have the strength to use it. This is easy to avoid, there are a great many mowers with easy-pull recoil chords or electric starts.
N.B. It is worth remembering that mowing a lawn and handling a lawn mower require a certain level of strength and expertise and it is not for everyone. (see image below)
2. Fuel: If you are pulling successfully and strongly and it is still not starting, it is also worth risking the schoolboy error ‘Doh!’ factor and checking the obvious… is there any fuel in the tank?
3. Fuel Tap: If there is a fuel tap fitted (check manual) make sure it is in the 'ON' position
4. OPC: The Operator Presence Control (OPC) is the bail arm that sits the other side of the handle and pulls towards you. Many people don't realise that if you let this go, the mower's engine and blades will stop. This is because it is a safety function. Have you let this go?
5. Choke: If you have a choke on your mower, make sure it is fully on (but remember to switch it off once the engine is warm)
6. Primer Bulb. If your mower has a primer bulb or bubble (usually a black or red plastic bulb located near the fuel cap) you may have neglected to prime it with a couple of squeezes. This can affect the starting ability of your mower.