Assuming you’ve already scrubbed the spark contacts with a wire brush to remove any carbon buildup.
And that’s about all I know about engine maintenance.
Didn’t use a wire brush, I scrapped the surfaces with my trusty pocket knife (that Son #2 says I abuse.) Made no difference.
Next step is new spark plug. The layout of the machine is such that I cannot easily remove the plug, lay it in contact with the frame, pull the tiller rope, and still be able to see if anything jumps the gap.
In thinking back, I’m not really sure I replaced the plug back when I bought the machine so it could have more miles on it than I know. Spark plugs are cheap so it’s an easy thing to try. If I have to dig into it any deeper (as in dismantling in various degrees) it can wait until glowbull warmthing hits and raises the ambient into the jacket-no-longer-needed range.
It is about time that I request that Son #2 sharpen my knife though.. ;-)