kawsaki gpx250r engine hole?

Question

on my gpx250r there is an open hole in the barrel (cylinder casting) on the left side. After a good flogging (ride) small amounts of oil seep from here. The manual and the microfische do not show this, but every second hand engine has it. Is there supposed to be something there?

Answer 1

I think you have your terminology mixed up.
The hole you're describing is on the cylinder head, not the cylinder.
Look at the gaskets - crankcase - gasket - cylinder - gasket - cylinder head - gasket - cylinder head cover.
The hole is a water drain hole.
If water from the road, or rain water gets into the spark plug recessed holes, it drains out that hole.
If oil is coming out of that hole, then the valve cover gasket is leaking and should be replaced.
Here's a picture -
http://www.kawasaki.com/Home/Home.aspx
Go to - Owner Info - Parts Diagrams - Motorcycle (continue) - 2002 (continue) - (select from the list below) Ninja250R (click here to choose) - Parts Diagrams - EX250F16 - Cylinder Head

Zoom in a couple of times and you'll see the hole.
Now go to "Cylinder Head Cover" - the 2 triangular holes in the cover, the spark plugs go down through those holes, then screw into the cylinder head. 11009A gaskets are most likely leaking.
Those gaskets seal against the cam caps - go back to "Cylinder Head". 92002A bolts go through the cam caps (the spark plugs also go through those trinagular holes and screw into the head).
11009 gaskets should also be changed, as oil can leak past them into the spark plug holes.
The spark plugs screw into the head at about the depth of that drain hole.
Every Jap sport bike with recessed spark plugs, have those drain holes.

Answer 2

No there isn't supposed to be anything there.

It is a drain hole. You may be leaking a small amount of oil from the top end somewhere and it makes its way out that hole.

Check to see if any oil is present around the spark plugs after a ride. If so then that's probably where it's coming from.

I am not totally sure on this as I've never had anything leak from that hole. But both of our 250 engines have the hole as you describe. Next time I do a top end job on one of those motors I will trace that hole for future reference.