Riding Mower Won't Start Just Clicks
Bad Battery Connections
Mower blades and engines cause a lot of vibration, bolts come loose from time to time.
Check that both connections, positive (RED + ) and negative (BLACK - ) are clean and tight.
Check the cables for damage, corrosion, mice find them irresistible
Buying a Battery
You can jump-start from any 12 volt vehicle.
Check battery voltage using dvom - attach volt meter to the battery and set to 20 volts.
If you have a reading above 12.5 volts - go ahead and attempt to start the mower, watch the voltage, a reading below 8 volts is a bad battery and needs to be replaced.
Always disconnect the battery before charging. Simply connect red to red, black to black, and plug in the charger.
The length of time on charge will depend how low the battery is and the amp rating of the charger. Usually 2-3 hours cooking time.
Solenoids are universal fit, they give lots trouble.
On the up side, the're easy to fit and cheap to buy.
Where's the Solenoid?
Husqvarna, craftsman like to hide theirs under the rear wheel fender or under the dash beside the steering column.
However, most solenoids will be easy to locate.
The first step in testing the solenoid - remove the spark plug.
If when removing the spark plug, gas pours from the spark plug hole - move on and check "Carburettor troubleshooting".
Turn the key, if the clicking sound persists - Go ahead and replace the solenoid.
If on the other hand the engine cranks over, move on and check for excessive valve lash.
Check the solenoid terminals, all wiring should be secure and free from corrosion.
Binding Starter Motor
Starters can bind against the flywheel. Turning the engine anti-clockwise by hand will unlock it.
To fix it - spray the starter gear with wd40 and retest. If it continues to bind, replace gear head or complete starter motor.
Excessive Valve Lash
Engines have valves which open and close in sequence. The inlet valve allows fuel/air mixture in. It then closes and seals the combustion chamber. After the power stroke, the exhaust valve opens, and allows spent gases out.
What's Excessive Lash
When valve lash is set correctly - you crank over the engine, the valves open and release cylinder pressure. This allows the engine to crank over at sufficient speed, in order to create a spark strong enough to start up the engine.
If you can, place your hands on the flywheel screen - try turning the engine clockwise.
If you're unable, it's likely you have excessive valve lash. Lash should be checked every season.
Adjusting valve lash requires an inexpensive tool called a feeler gauge.
Fuel Valve Solenoid
Gas in the Oil
Too much oil is a sign that your carburettor needle seal is leaking, unless of course you overfilled the oil yourself.
The needle wears over time, they turn pink when worn.
The fix - replace the seal or the complete carburetor. Using your manual fuel valve will prevent future problems.
Faulty Ignition Switch
Try the Wiggle Test
Try wiggling the wires at the back of the ignition switch while attempting to start the engine, you may need a helper.
Often wires simply come loose, but do check them for corrosion.
Faulty Control Module
Control Module Test
Like the ignition switch, wires come loose, have a helper attempt to start the engine while you wiggle the wiring connectors.
Check also for damage, water or scorch marks on the panel itself.
Faulty Starter Motor
Testing the Starter
Some starters will have a solenoid and starter motor combined in one unit.
To test, use a jumper lead to bring power from the positive (+) of the battery. to positive post of the starter. If the engine doesn't crank - Replace starter.
Most mowers will have the starter and solenoid separate.
Solenoid's are fitted to the body usually under the hood.
Cross a metal screwdriver from one connection to the other, as per picture. CAUTION THE ENGINE MAY TURN OVER.
There will be a small amount of arcing (sparking) as screwdriver contacts the poles. No risk of shock, as the system is only 12 volts.
If the engine won't crank over - your starter is faulty, replace.
Internal Engine Damage
Total failure doesn't happen often.
A hard life, low/poor quality oil without doubt increase the chances.