GPx250 oil leak

Looking at a GPx250 for my son's first bike; a couple have had reasonably fresh oil on the front of the motor, and I'm wondering if this is likely to be a valve cover seal or similar, or are they known for something more sinister?

just speaking from what has happened to me the rocker cover can leak but then so do most motors.....there is also a oil line on the front of the motor(you should be able to see it through the fairing on the left side) other than that i can't really think of anything else(it's been a while since i have had a look at that motor)check those two out it shouldn be too hard to see

Having taken the rocker cover off one of these a while back, if the oil is above the seam between the head and barrel then there's nowhere else for the oil to have come from than a weeping leak in the rocker cover. Also if there's a weep off the side then that's likely related to shit getting in the drain hole from the spark plug recess.

Thanks all - he's on the road, but not on a GPx, or even a Kawasaki. He's on a Yamaha FZR250... and loving it. 2 wheels, motor that redlines at 17000, decent brakes... he's ahppy as a pig in sh*t! The GPx we were looking at was just a bit too dodgy, and the ZX2Rs too expensive.