For small engines what works slick for long term storage or overwinter, emergencies etc is coleman fuel. Naptha or Blazo, Say in a generator. It's a first distillate of gasoline and low octane, maybe 50, with no additives but it doesn't sour, or turn to gum or varnish. Had stoves with ten or twenty year old fuel and they fire up OK.

 

I grow the corn that ethanol is made out of and don't have a problem running it in any gas engine but if you're going to store a carbureted engine for a prolonged time running ethanol the best thing to do is shut off the fuel to the carb and run the engine until it dies. Obviously a fuel stabilizer will help with the full tank of gas and seafoam seems to work for me.

If a carburetor is slightly gummed up and not completely plugged I have had surprisingly good luck with seafoam mixed 50-50 with gas sitting in carburetor for three or four days after running it for a bit before sitting.

 

As for some final comments on the Sea Foam question and answers and what led up to the questions. Ray Tasch came over to my house today and helped me figure out what was making my 223 run so poorly. As I stated earlier, I rebuilt the carburetor for the second time thinking that the old gas that sat in the tank for almost a year had gummed up the carburetor. The engine still would not run long enough or smoothly enough to figure out the problem. We checked the points, plugs, wiring, exhaust system, anything that would seem out of place. The engine would barely start, run very rough, backfire through the carburetor and the exhaust. Nothing made very much sense. Prior to putting the truck in storage in a friends garage I had done a complete tune-up so I new everything was new and adjusted and running very smooth....Until now!!! After checking everything over and scratching our heads, I decided to put the old condenser that I replaced with a new one when I did the tune-up over a year ago, back in the distributor. Guess what? The engine started right up, ran smoothly again, no back fire....good to go! So the deal is, probably not really bad gas gumming up the carburetor, probably didn't need the Sea Foam, probably didn't need to rebuild the carburetor (although it was fun and now I have a squeaky clean carburetor) I just needed a $8.50 condenser. Go Figure!!!!!! Thanks for all the comments and thank you Ray for your help today. (Ray, the gasket will be here tomorrow or the next day)