1999 wr400 leaking oil

I have a manufactured hole in the head above the cylinder on the right side of the engine. It's just above the top head gasket. No one can seem to tell me what goes in there and its seeping oil when the bike is running. Could someone tell me what goes in this hole? It is not tapped.

Decomp plug. There are fixes available from verious vendors. The oem one can just pop out (as you discovered). A search will yeild many stories similar to yours.

Thanks. Ill look it up. I searched for a while but came up with nothing.

your bike must have been modified to the auto decompression cam, the hole you are referring to used to house the auto decompression lever that pushed down on the right most exhaust valve, when you switch to the auto decomp cam - this lever gets removed and the hole gets plugged with a frost plug style insert.

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