Small Engines (Lawn Mowers, etc.): PTO Pulley Bolt keeps loosening up, pulley bolt, crank shaft

Question
Have a JD 345 with Kawasaki vertical shaft engine.  I can tighten the bolt that attaches the PTO pulley/clutch to the crank shaft, mow an hour or so, and when I stop the mower the bolt is half way out. I use a slip joint pliers to try to hold pulley mechanism still while I tighten the bolt.  Any ideas why the bolt keeps working loose?  Thanks.

Answer
Hello Niel:

This is Usually Caused by the Threads on the Bolt Being Worn or Not Enough Torque on the Bolt when Installed. If the Bolt Threads are Good, then Remove the Spark Plug and Go to the Local Hardware Store or Automotive Parts Retailer. Purchase a Bolt with the Same Threads and Diameter of the Plug. Make Sure it is 3" Long. Install the Bolt and Carefully Tighten the Bolt Until it is Snug Against the Piston. If the Bolt Does Not Touch the Piston when Installed, then Slowly Tighten the PTO Bolt and Allow the Engine to Slowly Turn Until it Jams the Piston Against the Bolt. Now you can Properly Tighten the PTO Bolt. Also, the I Suggest Using a Small Amount of Threadlocker Blue on the Bolt Threads. After the Threadlocker has Been Put on the Bolt Threads and the Bolt is Installed and Torqued Properly; Allow the Threadlocker 30 Minutes to Set and then Begin Using the Unit. 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 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. 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. Thanks.

Respectfully

John