2 cycle need to have oil mixed in the fuel to lubricate the engine. divide 128 by the mix ratio and that will give you the amount of oil to mix in one gallon of gas
Every 2 cycle engine is different, but there is a solution to your problem: I recently went to Lowe's and found a 2 cycle engine oil that you mix with gas that takes care of ALL mix ratios. Just...
I have 55 Rancher, use 50:1 oil:gas mixture. Husky users manual states all their engines less than 80cc use the 50:1 ratio, all above 80cc use 33:1 ratio.