Riding Mower and Tractor: Clicks but won't crank
When you hear a click but nothing else when you turn the key to the start position, you know the starter solenoid's control coil is getting power. A weak battery may have enough power to activate the solenoid coil but not run the starter motor. The starter motor needs a large amount of current to spin the engine. Check the battery and recharge it if it's weak. Clean any corrosion off the battery terminals and cable ends on the battery because corrosion inhibits current flow. A defective starter solenoid, damaged cable, failed starter motor or locked-up engine could also cause this problem.
Use the troubleshooting tips in this video to get your engine started when it clicks but doesn't crank: Riding Lawn Mower Engine Clicks But Doesn't Turn Over Video.
These repairs may help solve your Riding Mower and Tractor problem:
Replace the riding mower battery
If the riding mower or lawn tractor engine doesn't make any noise when you try to start the mower, it might be time to replace the lawn tractor battery. A good indicator that the lawn tractor needs a new battery is if you charge the battery, and it loses the charge quickly.
Replace the starter solenoid
The starter solenoid is a coil-activated switch that activates the starter motor. When you turn the ignition switch to the start position, the ignition switch triggers the coil inside the solenoid body to raise a high-voltage contact plate that bridges the terminal posts on top of the solenoid body. High current flows from the positive battery cable connected to one post, through the contact plate, to the starter cable connected to the other post, causing the starter motor to spin. The starter solenoid clicks when the activated coil raises the contact plate. Replace the starter solenoid if it doesn't click when you turn the key.
Replace the starter motor
The starter motor spins the flywheel to start the engine when you turn the ignition key to the start position. If the starter motor runs but doesn't spin the flywheel, check the starter motor's drive gear for damage. A defective drive gear won't mesh with the flywheel teeth to spin the engine. Replace the starter motor if you find damage to the drive gear. The starter motor may be defective if it doesn't run when activated. Other failures such as a locked up engine or poor current flow to the motor can prevent the starter from spinning, so check those issues first. Replace the starter motor if it won’t run and you've eliminated other possible failures that could prevent the starter motor from running.