Small Engines (Lawn Mowers, etc.): STIHL KM85R trimmer, stihl km85r, spark test

Question
Equipment:  STIHL KM85R 2 cycle trimmer.  Want start fequently when it get warm.   Spark test for plug doesn't show spark when crank rope pulled.  Don't know how to test spark module but resistance on the two terminal shows open.  Runs great when its running.   Has never died once its running.   3 years old and didn't do this until recently.  Don' know where to find repair manual.

Answer
Hello John:

It Sounds like the Coil/Ign Module is the Cause of your Problem. Is the Exhaust Port and Muffler Clear? No Carbon Blocking the Exhaust Port and the Spark Arrestor Screen is Clear. If These are Clogged even Slightly, it can Cause the Engine Temperature to Be Higher than Usual and Cause the Coil/Ign Module to Do this Also. Remove the Spark Plug and Wrap the Threaded Section of the Plug with Wire, then Attach the Other End of the Wire to the Engine Block. Now, Remove the Coil Shut Off Wire at the Shut Off Switch. Check for Fire. If No Fire, then Remove the Cut Off Wire from the Coil (removal of the blower housing required) and Check for Fire.  Turning the Engine By Hand (giving a Quick Twist with the Wrist) is Enough to Make the Coil Fire the Plug. If Still No Fire, then the Coil/Ign Module is Bad. Stihl Does Not Offer Any Online Support Other than Contacting a Dealer. You can Purchase a Service Manual from your Local Dealer or Visit their Web Site @ http://www.stihl.com/ Hope this Helps. I am Here if You Require More Assistance. Let me Know What Happens, Please. 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 9pm EST (US). My New Day Starts then. Thanks.

Respectfully

John