Prasinos,
If you want to compensate for a lost smaller jet temporarily while you wait for a new one, what you want to do is add something that will give you less 'fire' per the given quantity of fuel mix entering the chamber. So there is nothing going on with the air fue mixtutr, you are just 'cutting' the gas to lower its octane rating, so the engine will run slower (and maybe rougher) because each explosion in the chamber is less powerful. Rather than extra 2 cycle oil, add a little kerosene to the tank. Start with just a little (1/4 cup), and keep adding until the engine runs rough and stop; add a little gas to smooth it out. But you will have less power too. Kerosene also does a nice job of blowing carbon out of the cylinder, and it won't hurt a thing in reasonable doses. Back in the 74 oil embargo, there was plenty of kerosene avaialable from the Standard Oil wholesaler, and it made the gas stretch for the low-compression engines on the ranch (generators, pumps, old pickups, etc) and saved gas for the newer cars and trucks - old trick my Dad had learned during WWII gas rationing. Adding Coleman fuel (white gas) or alcohol may cause erratic detonation, and I wouldn't do it. The right size jet will be the best fix in the end.
