Consider cleaning the sparks and gapping them properly. All of my weedwhackers came gapped .020 to .024. I actually have the shop specs for those,a nd they're supposed to be .030. Coincidentally, after properly gapping them, they start on the first pull. Everytime. Also, clean the sparks, clean the threads, make sure you clean those while cold. May need to adjust the idle carburetor a little higher than default. When I properly gapped my latest Featherlite, I discovered it actually required a higher idle fuel flow to stay running... (and yanking the trigger to the bottom would stall it without tweaking the carb.)
When it comes to mowers, I actually have what appears to be a magical 4 cycle mower. 10w-40 oil has its own dipstick, takes regular 85 to 91 octane plain gasoline. And I'm in the process of dismantling the engine for my own curiosity since I hit a rock last year and bent the blade carrier shaft. (Another curiosity is that Honda makes Single Overhead Camshaft designs. Yep, your lawnmower could probably hit 5000 rpms without valve float or piston slap if its a Honda. Maybe more... and I wouldn't be surprised if their latest stuff not yet in "conservative" America is actually powered by 2 cyl VTEC or they managed to make single cylinder VTEC. We'll probably get those when they're old news, outdated and inefficient and outpaced on every other continent.) But lets not digress. Back to mowers and whackers:
All of my basic 2 cycle mowers have ALL died of heat death. Have you considered bad spark, bad fuel or bad head gasket? One of my Briggs, back in the day, used to leak combustion, kept running it until one day a valve got stuck and it wouldn't start at all (that's what happens when you have ONE cylinder and it has ZERO compression because of a stuck open valve. Then I took it apart and found that it had a gorgeous burn channel on the head gasket. Every neighbor and "mechanically inclined" redneck would tell me its hiccups were from "bad gas with ethanol." Well it WAS NOT the ethanol. It was a VERY bad head gasket and a very dirty overheated engine. These things overheat, and you need to realize that unless you've got active cooling on them, they DO build up heat, and eventually overheat. Run 'em 30 min, then set them aside to cool. If you cannot get your work done in 30 min. Leave it for another day. Overworking these little things without giving them an hour or so to cool, is a sure fire way to burn them.
While I'm at it, guess if I can FIND a head gasket and whatnot, I'm going to port the mower... see if I can get another half horse or two out of the little motor. Its pretty low compression, there's no water jacket... and lots of cylinder head meat to peel away to form new airflow directions.
* Destin Faruda misses doing such awesome shit on the coast with the crew, and wonders what might have been if he hadn't pulled his career's ship into Hara Kiri Harbor in Small Town Wyoming (tm).
* Destin Faruda can't blame anyone but himself. Small Town Wyoming (tm) looked good on paper to him... but it proved to be an erroneous calculation. Guess we're all entitled to pull into Seppuku Station once in our lives, eh?