Well it could either be a bad gasket or a crack or something. Most likely a gasket though. Where is the oil leaking from? Valve covers, cam sprocket cover, the head itself?
valve cover o ring might be pinched take it off and look at the o ring and see if it lookes pinched at all if it is look to see if u have one or put it back on and tighten the bolts down eveonely and check again
u can buy 1 for less than $1 i'm sure, it's just an "O" ring. If I was racing my quad I wouldnt want any oil coming out anywhere...except the competitors quads