Small Engines (Lawn Mowers, etc.): John Deere rider, john deere model, sectional index

Question
I recently purchased a 1989 John Deere, model 170, riding mower. It started, with some delay and operated just fine throughout the summer, but toward the end of the summer it ceased starting altogether. I purchase a tune-up kit and replaced the fuel and air filters and the spark plug and still nothing. I removed the spark plug from the engine and laid it against the block while turning the engine over and the spark that appeared was not between the elecrode and the plug. It appeared around the end of the plug in a continuous line that raced around between the plug and the engine. This continued for 10 to 15 seconds then the spark discontinued. The engine turns over and the fuel pump works but the engine won't fire. Once in awhile when I am turning the engine over it will fire just for a second then quit and go back to turning over with no results. I attempted to check the voltage from the battery but the needle on my multimeter spiked and blew the fuse. I will appreciate any ideas or help you can give me with this matter.

Thanks,

Dave

Answer
 Hello Dave:

 Wrap a Wire Around the Threads of the Plug and Attach the Other End of the Wire to the Engine Block. Check for Fire. If the Fire is As Before, then Replace the Plug and Check the Fire Again. If the Plug is Firing Properly, then Pour a Small Amount of Gas Into the Carburetor Throat and Try to Start the Engine What Happens? If the Spark Last for 10 to 20 Seconds and Quits, then, the Igniter/Ignition Module is Bad. You can View a Breakdown/IPL at this Addy http://jdpc.deere.com/jdpc/servlet/com.deere.u90490.partscatalog.view.servlets.H... and Enter the Model Numbers and Click Find. Then Select the Model from the Search Results Area. The Select the Sectional Index. The Select the Engine. Then Select the Folder # 16, Stator, Spark Plug Engine Wiring, Igniter.