It is very, very easy to over fill these engines, and that's due to 2 inherent issues. The first is the thick oil and checking the oil level when it's not fully heat soaked. The second being the weak scavenge side of the oil pump. Due to the inherent flaws of these engines, the best way for accuracy on oil amount, is to completely drain the system dry, then put in 2 3/4 quarts total. If you check these engines idling and on the kick stand, you highly run the risk of over filling, because at idle, the scavenge side of the pump and gear rpms is not enough to put the oil back in the tank. You actually should raise the idle (off idle) so that the scavenge side starts to put it back into the tank, then you can check it. So, in a case such as described herein this topic, if the bike is idling and on it's kickstand, the majority of the oil can be sitting in the crankcase, giving the end user a false sense that his engine is low on oil. So, oil then is added, and then on a ride with engine rpms above idle it goes back into the tank at a higher level, but it doesn't puke it at that point. The point it pukes it, is when it's back at idle (now all of the oil and excess is in the crankcase) then off idle and moving not giving it enough time to get back into the tank, the oil runs up the jugs, and pukes it into the over flow tube, of which should never be hooked into the air cleaner because then all that oil gets sucked up in through the carb and burned and the rest just pours all over the side of the bike. The oil that gets sucked up into the carb and burned in the chamber will emit white smoke.
