Hi all, I was wondering how much antifreeze there should be in my dad's DRZ-400 dual sport bike which i am riding. I believe the bike is an '05 model if that matters. The radiator is full but the resevoir down below is empty. I'd really like to make sure I'm doing the right thing before I break my dad's bike. Haha. Should the resevoir also be full? If so, how do i fill it?