Turn off the fuel petcock before you put the oil into the tank!
So... my bike is almost on fumes and I know the can is empty too. I hop on the bike figuring I'll mix up a tank on the bike as well as the gas can.
I measure the oil into the almost empty tank, then mess around a couple minutes measuring the oil into the gas can. Then I pump the gas into the tank and into the can and shake both around a bit to mix it up.
When I go to leave, I notice that the fuel line is blue... very very two stroke oil blue. Uh Oh! The oil settled into the fuel line and down before I was able to add the gas in. I get about half way down the block to get home before it starts hating life then dies.
Couldn't get it restarted after 10 minutes of pedaling it around. Today's chore... drain fuel bowl and line, and clean or replace spark plug. I might add a bit of oil back into the tank too... grrrrrrr