hey guys, what size tire tube would i use in the rear of my big red? its an 83 ATC 200 with stock size tires (25").

YES, i already know that tubes suck... my rims are pretty banged up and i dont have time to work on them... i want to get the trike mobile for a weekend hunting trip and i'll straighten them out later or replace them so the tires will hold air without the tubes.

so... what size works for the tube?