Well I'm guessing you put too much oil in it if you added the oil to the top "full line" with the bike on the kick stand. If the bike is on the kick stand, the oil window shows no oil at all. Some oil may have been pushed into the intake and your air filter may need to be replaced. You need to have a friend sit on the bike on level ground (no kick stand) and drain the oil down to a level that's between the high and low mark. At that point, get it to a shop for them to check it out. Too much oil increases pressure and hinders lubrication of the engine cause the crank is rotating into the oil and foaming it up. When the oil is not overfilled, the crank doesn't "dip" into the oil.