When you have a hard starting or slow starting lawn mower, the engine begins to turn over slowly and then it finally gets up to speed. This is a sign that the lawn mower is developing an engine problem and it should be checked out as soon as possible. If not, you will have a lawn mower that does not want to start up.
If your lawn mower doesn’t start, well, you won’t be getting much grass cut today! There could be many different things that prevent your lawn mower from starting normally. The grass could be clogging it up if it is a self-propelled or push lawn mower or your could have a carburetor choke problem that is giving you a slow start.
Check both of these items to ensure that you the choke is closing when you try to start and that there is nothing slowing down the lawn mower blades or the PTO shaft on a riding lawn mower.
The choke should gradually open if it is an automatic choke as the engine is starting. If it does not and hangs in the closed position and you see black smoke coming from the exhaust, the choke is definitely the problem here.