hydro-lock in a Kohler

[crazy charlie]

I think I will install a valve for shutoff.Especially since my mower is now doing exact same thing a season and a half later after
new carb install.Got a semi hydrolock the other day with 2-3 times tried starting and just a click, then it cranked and started and blew smoke for 30 seconds just as it did last year.Fuel tank was 99% empty so it had been dripping for a few weeks .Charlie

I see 1/4" cutoff valves on eBay really cheap.Is 1/4"correct?? Looks just like the cutoff on my snowblower.Charlie