Small Engines (Lawn Mowers, etc.): Mower blade wont engage..., john deere l120, blade style

Question
John,

I have a John Deere L120 lawn mower.  It has worked great for a few years but this week the blade suddenly stopped engaging when I pulled the yellow knob to activate the mower blade.  What had happened was I had cut the backyard and shut off the mower to open my gate and go to the front yard.  When I restarted the mower and went thru the gate I then pulled the yellow knob to get the blade moving again and nothing happened.  I have tried several time shutting down and restarting the mower but the blade will not engage.  I looked under the hood and wiggled the wires and tried to make sure the connections were all tight but nothing has helped.

Any advice you have would be appreciated.

Thanks,
Steve


Answer
Hello Steve:

You can View a Breakdown/IPL of the Engine and Mower at this Site Addy, http://jdpc.deere.com/jdpc/servlet/com.deere.u90490.partscatalog.view.servlets.H... and Enter the Model Numbers (L120) and Click Find. Then Select your Model from the Search Results Area. Then Select the Sectional File. Then Select the Section of the Mower you Wish to View Online. The Following is a Basic File I Made for Checking the PTO (Blade Engagement). Check the Fuse/s. The Most Common Cause for this Problem is the PTO Ground. A Quick Ground Check is to Use Another Wire and Ground the PTO at the Harness Connection Nearest the PTO. Be Careful and Do Not Ground the HOT Wire. Use a Multimeter and Locate the Ground Wire. Clean the PTO Ground and All the Connections for the PTO Wiring Harness. If you have an Ohmmeter, Disconnect the Wiring Harness from the Front of the Clutch and Check the Resistance of the Clutch. You should have around 4 or 5 OHMs. If at or near Zero, the Coil has Shorted. The Following is a Basic File I made for Setting the PTO CLearance. Any Input is Appreciated. **Some of the Newer PTOs cannot be Adjusted. If you can Get a Blade Style Feeler Gauge between the PTO Magnet and Clutch, then Set the Clearance at .015in. The Newer PTOs have the Same Set Up as the Older PTOs, except there is No Adjustments. I Suggest also that you Rig a 12 Volt Light for Testing the Current Flow to the PTO while Operating the Mower. If the Light Blinks During Operation, then you have a Bad Connection somewhere to the PTO Clutch. If the Light Stays Steady and the PTO Still Kicks in and Out, then it is the Adjustment. You can Also Try Turning the Spring Loaded Adjuster Nuts 1/4 Turn and Operate the Mower. Do Not Adjust Over 1/2 Turn. If you have Adjusted to 1/2 Turn and the Problem is Still Present and you Know the Voltage to the PTO is Steady, then Replace the PTO.** If you Hit a Snag or this Does Not Correct the Problem,  I am Here if You Require More Assistance. Hope this Helps. Let me Know What Happens, Please. May the All Mighty Bless You and Yours. Thanks.

Good Luck

Respectfully

John

PS: I am Allowed to Answer 10 Questions a Day. If you See I am Maxxed Out, then Try Submitting your Question at or Just After 8pm EST (US). My New Day Starts then. Ratings and Comments are Greatly Appreciated. Thanks.

Respectfully

John