Hey Gang. I know I should have the ID.#, how ever there are no plates left on the engine , how ever its a MTD. built, with a 21 HP. Briggs, ohv, Vtwin Cast Iron. Please bear with me. I have spark,fuel (elec.sol. on carb) every thing is fine as far as it goes,. The only way it will run is to unhook one coil, makes no diffrence,either one, as long as one is unhooked it will start and run fine, except it is running about one third throttle, if I touch the ground off of coil to engine ground it will idle down and run as it should ,, however when I ground the kill wire to engine ground there is a spark coming thru the kill wire, if I hook it back to the coil when running it dies,, now there is no ground left any where on the engine, I have unhooked the kill wire, carb seloniod plug and unhooked it from the carb so that all that is left is just the wire from the plug to the coils, I have made a new kill wire for the coils as the first one showed up as haveing a break in it inside the shielding. All safetys are bypassed but that should not have bearing on just the engine turning over and running. For the life of me I cannot figure out how there is spark comeing out of the kill wire and how it makes the engine idle down, I can unhook bothe coils and it will still run one third throttle unless I ground one of the wires to the block or some such ground... I have put a meter on all the grounds and hot wires and they show to be good and not have a short in them,,, that is just the carb ,, kill wire, as I must hook up the selonoid for carb to operate... I am going nuts,,, Oh yes I am checking spark with plugs out, so that it don't start every time I turn it over to check it.But as stateted above if I hook up both coils I lose spark. and I have tried new coils to make sure there is not a short inside of one of them...Help............. thanks for any and all.