"Jason" wrote in message ...
Have a 35 hp merc outboard... currently with a 6 gallon gas can.. is there
any reason why i cannot upgrade to a 12 gallon?

They're available, but be careful what you wish for.....

A near-full 12 gallon tank will weigh near 75-80 pounds -- possibly a little
problematic hefting around during refueling procedures. Just a thought....

JG