Definitely not the rocker cover gasket then ? If your water cooled and it's your cylinder head gasket it would be pretty obvious ( and bad news ). Might be worth just nipping up all the rocker cover bolts just in case. If it's bad you'd be finding it a touch more difficult to start on the button 'cause of dropped compression.
Hope it's not too serious
Definitely not the rocker cover gasket then ? If your water cooled and it's your cylinder head gasket it would be pretty obvious ( and bad news ). Might be worth just nipping up all the rocker cover bolts just in case. If it's bad you'd be finding it a touch more difficult to start on the button 'cause of dropped compression.
Hope it's not too serious