Be very careful about use of additives. While most things can take the additives running thru the system, leaving this material in the carbs, fuel lines and in contact with parts that don't like it can do more harm than good.
More important than this is to be sure you store the sleds in something that doesn't get hot as he!! in the day and cool at night. There are things in gasoline right from the refineries that do a decent job of stabilizing your gas and if you put these sleds somewhere in the shade and better yet start them once in awhile, without the additives, you aren't likely to have plastic parts desintigrate in the fuel tank over long periods of storage.
I have stored my efi sleds since 2001 in cool places and run them once or twice over the long summer and have yet to have a problem. (sometimes 5 months between)
I do use stabil in gasoline that is NOT in the tank and stuck in a fuel filter, fuel pump, carb/ injectors. Only in cruise cans and gas cans....Maybe it won't hurt them much, but maybe it would and you would feel like a dummy to be causing more harm than good wouldn't you?? Some of the solvents can react with all the different parts in a sled. You can't hurt things pulling the oiler back and fogging it up but aside from that...I would be careful.