Save yourself alot of wasred time and headaches and junk the cox engines. You can pick up a nice running .061 WASP AP HORNET for $40, and some spare glowplugs for about $4.50 each, as opposed to $9.00 for a COX glowhead. I also have a NORVEL BIG MIG .061[not the hipo version that is inconsistent] that is a nice running engine on 15% fuel. Top off fresh gallons of fuel right after you first open them with caster oil all the way to the top, and shake it up. NORVEL SELLS AN INTEGRAL FUEL TANK/ MOTOR MOUNT that will make retrofitting your LIL SATANS easy, and move the CG forward at the same time. COX can be made to run, if you want to make engine work part of your play time. I still run a RC glider with a BABYBEE and an external 2oz tank that gives me 15 minute engine runs, but once it wears out I will have washed my hands completely of the little %#@&*s