Small Engines (Lawn Mowers, etc.): no spark no start -click, jumper wire, grass catcher

Question
cub cadet yard bug riding mower
was working fine stopped to empty grass catcher
and would not start again just a click sound.
battery 12v dc; 12v dc at sol drops to 4vdc with key turned to start and holding down brake .?
solenoid or starter or (plug is only 1 season old)oil level ok.

Answer
Hi Linda,

I'm sure the problem is not as simple as: The blade engagement switch or lever was left on after you emptyed the grass.
I would check the starter first.  Jump the positive battery terminal to the starter and it should crank over.  If not, the starter is bad.  If good, then you will need to trace the entire circuit from the starter to the battery.  All testing can be done with a 12 volt light or a voltmeter.   The solenoid, switches the battery power to the starter, when power from the key switch is sent to the small terminal on the solenoid. To test the solenoid, first make sure that you have power at its large terminal which comes from the battery. Then jump power from that terminal or the battery positive post, to its small terminal. You should hear a click and the other large terminal that feeds the starter should be energized. If not, then the solenoid is bad. If good, then continue tracing the power through the key switch to the battery until you find the break in the power path. Most equipment has safety switches in the seat and on the blade engagement lever. Check them by temporarily bypassing with a small jumper wire.  

Let me know how you make out.
Michael