When I try to engage the electric pto on my toro LX427 lawn tractor it clicks but does not engage the mowing blades.

SOURCE: blades not engaging

Tim, first turn key on engage and disengage blade button. See if you can hear the clutch making a clicking noise. If not check switch., if not your problem is in the clutch.

SOURCE: mowing deck makes ticking noise when blades are engaged.

A FEW THINGS TO LOOK AT ARE ,1THE PULLY SHIELDSMAKE SURE THEY AREN'T BENT TO CLOSE TO THE PULLEY'S.2 THE PULLEY BEARING'S MAY BE WORE OUT AND TO BREAK .3LOOK UNDER THE DECK TO MAKE SURE YOU DIDN'T GET SOMETHING TRAPED IN THE CUTTING DECK.HOPE THIS HELPED.

SOURCE: I have a Craftsman Lawn tractor. Blade leaves grass uncut.

Hi Tom,
Check your spindle shafts for loose play. If your bearings are worn out and sloppy, the belts pull the spindle to one side and an angle cut results... close cut grass at outer edge and high in center will leave this grass trail you are describing. I'd replace the bearings next year for sure.
I hope this helps... Good luck!

SOURCE: RE: Lawn mower blades will not engage

This sounds like a faulty ground condition, the PTO clutch requires a ground provided by the chassis wiring harness to function and a ground for the ignition switch to kill fire to the coils. The other components work as they should because the voltage regulator, fuel shutoff solenoid and starting interlock system have their own grounds. The ignition switch in these mowers is a large round plastic switch not capable of grounding itself, it should have a black wire leading from the terminal marked "G" on the backside of the switch.

to diagnose a faulty ground you'll need a basic 12V test lamp:

Unplug the switch and and install a the test light clip on the positive terminal of the battery, probe the ground wire in the unplugged harness that corresponds with the "G" terminal only. If the ground is good the lamp in the test light will illuminate brightly, if poor or faulty the lamp will not light or be noticeably dim.

Further verification of a faulty ground or failed PTO switch can be tested at the PTO Clutch harness, turn the key on, engine NOT running, and pull the PTO Switch to the engage position, with the test light clipped onto the Negative Battery terminal or chassis, back probe the connected PTO clutch terminals. If the PTO switch is good and the ground is good then Only one terminal will illuminate the lamp, if both wires illuminate the lamp then the ground is faulty, if no lamp illumination then a loss of power is suspected, check the terminals on the PTO switch and Ignition switch for power.

Typical Ground termination locations are on the frame near the rear of the tractor frame, above the transmission, in the steering column area and near the solenoid, check for a loose or corroded eyelet terminal, broken wire, or a missing fastener in these areas.

SOURCE: toro riding lawn mower pto switch not engaging to turn blades

see if you have power and ground to the connector that goes to the clutch it could be a bad safety switch