I just bought a used Craftsman DGT 6000. It has a 2 cylinder Kohler engine. It is a CV740 type 0024. If I am sitting on the seat looking forward, the left hand side fires, the right hand side does not fire. Pull out right hand plug, engine starts, runs ten seconds, dies. Take same spark plug out of left side and put in right and the engine just spins over, does not even try to hit. Any ideas? Does this sound expensive? Thank you for your time.