Oil leak on kawasaki 250 stockman cant seam to find it

310ml all the best.

Try looking under seat on top frame area. See if that helps

If the bike is real bouncy with no dampining you need to have shock rebuilt you cant just add oil to fix.Most rear mono shocks have a little bottle of nitrogen gas on side of shock.When shock seals go bad the oil and gas leaks out. Most times it is cheaper to find shop to rebuild shock then buying new one.Mono shocks can run anywhere from 250.00 to 500.00$.you can get rebuilt for about 100.00 to 150.00$ depending on parts needed.

1. Oil plug gasket 2. clutch cover gasket, 3. Center case leaking
4. TOO much oil in crankcase, 5. Shift shaft seal. 6 Counter shaft seal.

incorrect jetting
incorrect ignition timing
incorrect plug heat range(could run a 9 or 10)
intake leaks
exhaust leaks
incorrect fuel oil mixture
overheating
is it burning the electrode off or carbon fouling the plug
sorry for the long list, there is probably a few you might discount as you have already checked

Check the cam cover, see if the bolts are all in their places and at the right tension (tightness)

If none of the bolts are missing, replace the cam cover gasket.

you probably have a leak! It is possible, (depending on what type of oil you put in)
that the oil dissolved the gasket, or removed sludge from an existing hole, causing it to open. but if you dont have any oil spots..well....thats a whole nother story.
terribly sorry!!
i hope this helps in some way!

not sure if this will help, but the crank case has a breather tube that is around that area. if the bike is on its side or has been doing wheelies, some oil can get thru the breather hose causing that problem.