Small Engines (Lawn Mowers, etc.): Mower wont turn over., automotive cables, battery cables

Question
My riding mower won't start by turning the key.  I charged the battery and all I get is some clicking noise and a hum sound.  If I bypass the solonoid and jump start it giving power directly to the starter it starts.  Any help would be great.  Thanks.  

Answer
 Hello Ken:

 The Starter could be bad. 1- Is the Battery you are using to jump to the Starter a Car Battery? 2- Check ALL the Battery Cables for Corrosion. If you replace them use Automotive Cables. The larger the Diameter Cable the Better the Amp Flow to the Starter and the Less Starter Problems you will have. Take a Volt Meter and Check the Soleniod to see if it is good. Use your Meter to check the AMP pull of the Starter. If you are using a Car Battery to jump the Starter then Replace the Starter if All else is Good.  Hope this Helps.

 Good Luck

 Respectfully

 John