if there is no spark, acess your on/off switch and remove one wire. now see if you have spark. (i'm assuming you have removed the spark plug wire).insert the spark plug into the wire,hold the plug against the head so that the ground electrode is making contactif you still don't have spark,it may be the plug, if you can't ck. continuity, try another plug. contact a dealer for an ignition system, parts break down and have at it , may require special tools, once you get to the ign. system ,whether points/condencer 0r electronic, look it over for damaged wire or the obvious if points ,they may not be gapped correctly or you could let the dealer repair it, the cost of which may be as much or more than a new one.Mccullock has changed hands a few times which may pose a problem.
stan, April 2008