If you are unlucky and pour some ATF in the tank before you fill up, you may manage to get a big glop of it in the intake. This may or may not cause your bike to run like crap as it tries to fire on a heavy mix of ATF. This may or may not cause you to cuss loudly and think your bike is done for. I suggest letting your bike idle while you rock it back and forth to try to distribute the ATF throughout the fuel.