You need to do a little mowing or at least work the governor to open the throttle fully to check the exhaust for smoke
No smoke will be something leaking pressure into the engine like a cracked head, blown head gasket worn rings
Lots of smoke will be worn rings / hole in piston .
Double check the oil level & smell
A leaking float will allow fuel to get into the oil thinning it down causing it to bypass the rings
As HLW already mentioned, lots of oily fume coming out of breather can be a stuck reed valve
Lick your finger and place it near the tube
It should only blow if the valve is working
If it both blows & sucks then the valve is cactus
I have found kawasaki engines very prone to bore wear if the air filter is not 100%
My usual "test" is to stick my finger in the manifold after removing the carb
If there is a dusty paste deposited on the sides then worn bore is a certaincy
Good thing is all of them have responded to a quick hone & new rings
I have only ever had one Kawasaki engine blow ahead gasket internally
And that is on par with Honda
Kohlers seem to do about double that and of course B & S inteks at least 2 every season , best year was 22 out of around 300 total jobs a year
