I just got done riding and noticed top of engine was wet with oil looks like its comn from spark plug hole but it runs strong and have no issues could it be the two plugs to check valves are leaking. Never noticed this before i was jumping the bike alot today and was riding it pretty hard on and off the gas and was braking into the corners and throttling out pretty hard too. only the top of the engine is wet not the cooling fins and down the rest of the engine. Like i said bike is running strong and doesnt backfire or pop or anything.???