a cc (cubic centimeter) is a milliliter, not a centiliter..there are 1000 cubic centimeters in a liter, and 1000 milliliters in a liter...

A centiliter isn't the same as a cc....

There are 29.57 cc in an oz...(fluid)

550cc/29.57 = 18.6 oz (fluid)

If gas weighs ~ 6lbs/128 oz, then I say his fuel load weighs ~6(16)/128(18.6)=13.95 oz weight.

For reference, the only metric tank I own is a 220 cc..it is roughly an 8oz (fluid) capacity...

Not picking on you..I too am glad I live in the US and don't have to make these devilish conversions often..LOL