You need a flexible flat head screwdriver. It looks like a regular screwdriver except the shaft is a tightly wound spring.
If it is a fuel injected engine then you can not adjust the idle, it is computer controled. There is no idle adjustment. If it is a carburetor then there is a small screew over by the throttle cable, down towards the bottom of the carburetor.
bad seal in between your intke manifold and carburetor
You haven't really stated what you are trying to accomplish.there is a set screw on the bottom of the carb on your left as you are sitting on the quad you can adjust the idle up and down using this it changes how lean you are running.
Inside the bowl-like affair at the bottom of the carb.
At the bottom of the lake.
That is the main jet needle valve.
underneath the seat where it meets with the bottom of the tank
The torque specifications for the top and bottom fork yokes on your Kawasaki 250, is 160 pounds per square inch. The bolts should be torqued in 40 pound intervals.
top centre, bottom right, top left, top right, bottom left
The fuel mixture is probably set to rich. Also, the wrong spark plug (with regard to heat range) could be in the engine. If you have an adjustable carburetor with mixture adjustment screws, try turning the screw (probably located on the bottom of the carburetor, in the middle of the bowl) inward 1/8 to 1/4 of a turn. This will lean the mixture. If you have a no-adjust carburetor, then there is not a lot you can do to change the mixture. Try using/replacing the spark plug with the correct spark plug as recommended by B&S. Good luck!
The gas tank sholud have a valve near the bottom of the tank on either side. Look to see and then continue to undo it/and or the gas line, or follow the gas line to the carburetor and undo it there, remember to remove the tanks gas cap to allow air in to permit the gas to drain.
at the very bottom under the skid plate