Pull the float bowl off & check for water
If there is water there , check the fuel tank by draining some fuel into a glass jar .
Check the fuel can you used to fill the mower with .
I am guessing you've never dealt with a ZG222.
The float bowl is inaccessible to most people. The carburetor is BURIED down in the valley of the engine, with covers, air deflectors, filter, and a bunch of other stuff in the way just to get TO the carburetor, to just see it. Then in order to get it off, you have to remove at least one stud from the intake manifold (well, that's the easiest way), and the 2 bolts-leave one stud in the manifold, slide it back, disconnect gov and choke link, fuel line, wiring harness, then remove it. Gaskets will be required. While in there one could replace the restrictor with one from a ZG227, and now you have about 5 more horsepower
A carb cleaning on a ZG222 or ZG227 or ZG327 is a 2 hour job for someone whose done a few. Half a day project for those that haven't.
Or.....the easy way to diag.
next time the mower starts to act up, pull the choke lever up. If the engine begins to smooth out as you are pulling the choke, it means that the carb is starving for fuel somehow. Typically that means there is a restriction in the line or tank, possibly a fuel filter or maybe even a fuel pump issue. At that point, it's simply a matter of narrowing it down.
On the right side of the mower behind the RH Rear tire, there is a valve. Make sure it's not been hit by debris, to the off position. If it's still "on", grab a glass jar and put it under the valve. Turn the valve to "drain" and catch the fuel that you can in the jar. What do you see in the jar? Ideally you wanna see straight gas.
If the valve was on, and no water/dirt comes out when you drained it, you're gonna have to do a fuel flow test and this is not something that most novices or even amateur mechanics should do at home. You need to know what to look for among other things.
