After you put in the oil, you should start it and let it run for a minute or so. Stop the engine, and immediately check the level, and add more to bring the level up to the mark. Do this while on the center stand so the oil remaining in the engine isn't pooling to the left. Also, if the bike has been sitting for a couple of days, you may notice the oil level has dropped a bit. Don't add any more until you start the engine as described above, and check the level. Sometimes, the check valve on the oil pump will leak a bit, and oil will fill up the crankcase. You may think it's low, but after the pump gets the oil back in the tank where it belongs, you should be OK.