Just bought a 1982 Yamahoa Virago 750 that sat for about 5 years.  Cleaded the carbs, gas tank and all tubes are okay.  It is very difficult to start, but itfinally does and now after riding it for about an hour gas is getting in the oil.

Do I need to replace the rings are what?

Thanks  

HI; Have you checked the float,needle and seat? Check the vacume lines from the carbs to the crank case.if any. The only way to get gas into the crank is through the carbs. Have you checked that the chock is closed? If closed or half way this will make the engine run rich and dump excesive fuel in the crankcase. I have had this happen to a friends 250 Kaw. the leaver had a spring that closed the chock.The shaft was stuck and the butterfly was stuck 1/2 way. Just make sure that the valve is fully open.
Check the air filter and see if it is full of gas. If so you might have a bad needle and seat.
I hope this helps srcuffy....