if it's the outer case, try taking the side case off...and see if most of the gasket is still on the case/motor..if so..get some hondabond..or yamabond..put some of this on the spot where it's leaking....try not to put alot on it..you don't need much to seal it..put it back together..it shouldn't leak anymore..as for a gasket period..i've used alot of after market gaskets..and never had any problems.i have a 1999 honda trx 300ex. it has a oil leak and a need a crank case gasket. any one know a good place to get it relatively cheap?
I use to use RTV sealant a long time ago, until a piece broke off on the inside of the engine and stopped the oil pump up. Hondabond stays softer than RTV sealant and is less rubbery.I used red rvt gasket maker and it never leaked a drop