It spits fuel out of the carb because the inlet valve is open when the piston rises forcing the fuel back out the carb
This happens when an inlet valve sticks open or an inlet valve seat falls out or something gets stuck under the valve like a chunk of carbon or a screw from the carb butterfly
So it is off with both rocker covers and have a good look at the rockers while rotating the engine
all 4 valves & springs are the same length so when the piston is in the firing position that side the rockers will be parallel
Then it is off with the head to see what is root cause
Or just pull both off
You will need new head gaskets regardless of all of the brain dead morons on You Tube who show a head gasket, say " that looks fine so it can go back in " they can not .
Kohler have their engine service manuals available o line for a free download
Kohler parts prices are not subsidised like B & S ones use to be
