You can loosen up the bolts just enough to get a small screwdriver in and spray it with brake clean to remove any oil and the use your finger to push in some yellow gasket sealer. Its a one time shot as its a pain to remove. Be careful not to damage the gasket with the screwdriver. RTV sealer will blow back out after a few runs.
I think the reason for the gasket failure is ring blow by on the piston.
you have two ways to solve this the cheap and easy way is to drill a few more larger holes in your oil catch can so the gasses can exit. or pull the cylinder off and hone and re ring it.