[Spicyunicorn]

When it acts up pull the plug right away and see if it's wet when you has the carb off did you check float level? Blow air through the inlet and raise the float air flow should stop when float is level how's the pulse line from motor to fuel pump make sure it is clear they can build up junk in them over time also make sure there's no droops in that line... Sounds like you've covered a lot of the basics someone else will chime in with another idea