We run multiple Kohler and B&S gas engines up to about 30-hp on all kinds of equipment.
Highly recommend installing a fuel cutoff valve in your fuel line near the carb. Run every engine 'dry' at every shutdown.
To shutdown just run at rated RPMs, close valve, run dry. Turn off key.
This prevents ethanol-laced gasoline from sitting in the carb (1) slowly destroying gaskets and (2) deposition of varnish clogging needle / seat / float (note some maybe most engines use plastic floats subject to ethanol degradation.
Might consider using highest grade gasoline, said to have zero ethanol. Cheap insurance. Always use fuel admixture like Sta-Bil or similar---especially with low-grade gas having ethanol. Especially in saws, weed munchers, any 2-cycle.
Caution when transporting (valuable but expensive lesson learned): fuel shutoff valve lets engine run dry after loading in truck / trailer. Going down road bouncing CAN / MAY allow fuel to get past bouncing needle / seat as float bounces and flood crankcase with fuel IF NOT RUN DRY BEFORE HAULING. Creates a bit of a problem when cranked with crankcase overflowing with gas-cut oil.
I've been told by different dealers of different brands that the electrically operated spring-loaded anti-thingy screwed into the bottom of the carb is there ONLY to prevent fuel leaking from carb, creating a puddle, causing or contributing to a fire--nothing to do with anti-backfire or anti-dieseling of gas engine. For what it's worth. Replaced a couple of those painted green until got tired of failures and plugged hole.
Sidenote: because of what I otherwise do I had access to equipment to check presence of ethanol in gasoline. Did so after seeing truck mistakenly (?) dump wrong grade fuel into labeled tank. Got me to thinking. After finding ethanol in more expensive "non-ethanol" gas I transitioned to field testing before purchase by setting up micro-lab on tailgate. Made me extremely unpopular in small town as would usually draw a crowd of curious good 'ol boys. Owner comes out, says can't do that. Why not, paid for the gas. I'm not attuned to YouTube and one day a younger coworker tells me to watch a video of a guy testing gasoline. Damn, missed my opportunity for fame and fortune. All I got was a state investigation. And a cut of some of the fines.
Please post back your continuing experiences so we may all learn.