Appliance service valve
Stop Valve Key
The gas valve for the water heater should be turned on when you need hot water and off when you do not need hot water.
Cold feed
primary flow
You can get the float valve assembly for your Kawasaki KE 100 on Ebay.
primary return
Cold feed
Isolate it from the water supply then replace the defective valve
What if your float is not floating? Food for thought... If your float has gone bad then it wil not give enough force to close the Float Valve. Get a new float. If this does not fix it then the float valve you got is defective.
It very well could be, or a problem with the float. Remove the bowl off the carburetor, remove float, needle valve, and seat. Clean all parts good with carburetor cleaner. Float the float in some fuel to make sure it floats (when should not that any fuel inside of it). Put needle valve, seat, and float back on and open fuel valve a small amount, lift float up to see if it will shut fuel off, if it does reinstall bowl. If not you may have to replace the needle and seat.
To fix a toilet float that is not working properly, you can adjust the float arm or replace the float valve. First, check if the float arm is bent or obstructed. If so, straighten it out or remove any blockages. If the float arm is fine, the float valve may need to be replaced. Turn off the water supply to the toilet, drain the tank, and install a new float valve following the manufacturer's instructions.
primary flow