At least you are getting fuel to there. Cylinder problem/ compression, is what I mean. A hot plug or lean oroblem can melt a hole in piston. Worse case scenario, but it sounds like you are working out most other possibilities. How cold is it there? Mine had lots of trouble starting in 40 degrees. Does the kick feel like there's plenty of compression? And it kicks free with plug out? Is the kicker worn to where its hard to get the full hard kick?
I have had trouble finding spark, by the sight method, when looking for it with lights on. You can remove plug and put the cap on it, so the engine spins free, but always use a plug, or it may cause damage to ignition. Usually any spark, is a good one. Not always, but thats what makes that kinda problem hard to find.
