I ran out of petrol recently and was 2.5km short of the petrol station I was aiming for. I could only get 12 litres of petrol into the tank which I'm told takes 13 litres. I was only filling it up with the bike on the side stand and was wondering whether the missing litre might have still been unusable in the bottom of the tank or perhaps I could have got a bit more in the tank had I filled it with the bike vertical. The bike is a '00 Honda vtr250. If you're immediately going to use a few litres, is there any harm in filling the tank beyond the suggested limit but without using the overflow vent?