The recommended amount is 1 oz per gallon up to a max of 2 oz per gal.

You don't need to add extra stabilizer with Seafoam. If you do though, use Stabil Marine formula.

'use Stabil Marine formula'

YES! The best stuff yet devised by man. But, like OD said, you don't need it in your 2-cycle mix particularly because 2-cycle oil these days already has a fuel stabilizer in it and Seafoam is also a fuel stabilizer. My 4-cycle mix is 1 oz/1 gal Marvel Mystery Oil and some Sta-Bil Marine Ethanol Formula. Since the Sta-Bil is so concentrated, I buy the 8 oz dispenser bottles, keep them in my vehicles and add an ounce at every fill-up. It keeps my cars and trucks running right and the catalytic converters sweet.