By not starting, do you mean it does not crank over, or do you mean it spins the engine but won't run. 2 very different problems.
If it is the first case, If you can find the starter solenoid (see attached) and short the big terminals you'll know if it is that.
Otherwise, could be fuel or spark. If your spark plugs are black, check your air filter, sounds like its running rich
When you said clicking earlier sounds to me like the starter solenoid.
