Thanks yapoy and stafeyer.
I think it was really gas. I remember the pump that was used and it is gas when I checked it again. And the smell of the fuel tank cap, its gasoline!!!!

Yes, I think the best thing to do is to drain the tank and fuel system and hopefully nothing goes wrong with the engine. Keep you updated what happens next.
Lesson learned: Tell the gasoline boy/girl what fuel to pump in. Never rely on them to read what was written on your fuel cap/lid. And watch them while they are filling up, para sigurado kung tama ikinakarga nila.
