Once with the Apex I fouled a plug, copper in the NGK 9 heat range. Cold and humid -22C morning, first ride of the season trailer trip. Started as usual but stalled after 1 minute while I was further starting another sled. Can blame it to having shutting it down to early prior night just to unload sled from tailer/valves needing adjustment after 20,000km/old gas. Took me hours to get it started until I found on this site with my phone the hot water on thermostat sensor trick. I knew what would of prevented this that morning.
I quickly changed back to bullet proof iridium plugs afterwards! Never was able to foul these on my old 2 stroke SRX or kids old and new Snoscoot. To me that's worth more than 2HP.
Especially after reading on another thread about the Sidewinder starter automatically cutting off the second the engine starts...I'm happily staying with iridium already on hand to install in my '22.