My thought is "Has this guy changed the oil since he bought it?!"
Fill your radiator with 50/50 and then change the oil. Ride the bike for a little while, then change the oil again. Ride it again, then stop and let it cool down. Compare the radiator coolant level and check the transmission oil for milkyness. If the level of coolant is lower and the oil is milky again, then you need to replace both parts like said above.