THE ACFT COLLIDED WITH POWER LINES AND CROPS AFTER A LOSS OF POWER WHILE ON A TRAINING FLT. THE CFI AND STUDENT PLT WERE PRACTICING IN CRUISE, SINGLE ENG SIMULATION BY LEANING THE RT ENG AND SETTING A 'ZERO' THRUST CONDITION. THE STUDENT WAS THEN TO SET THE ACFT UP FOR A SINGLE ENG APPROACH TO THE RICHMOND, IN, AIRPORT. WHEN THE STUDENT PLT HAD TROUBLE MAINTAINING AIRSPEED AND ALTITUDE THE CFI TOOK CONTROL OF THE THROTTLE QUADRANT BY MOVING ALL LEVERS FORWARD. SHE CALLED FOR, 'EVERYTHING UP OVER THERE,' MEANING THAT THE STUDENT INSURE ALL SWITCHES ON THE LEFT SIDE WERE IN THE 'UP' POSITION. WHEN POWER COULD NOT BE RESTORED THE CFI LOWERED THE LANDING GEAR AND FLAPS, FLEW THROUGH THE POWER LINES AND LANDED IN A CORN FIELD. BOTH PLTS STATED THAT THEY HAD PARTIAL POWER IN THE RT ENG AND COMPLETE FAILURE IN THE LT ENG. EXAMINATION OF THE WRECKAGE REVEALED A SMALL AMT OF WATER IN BOTH CARB BOWLS AND A LEFT MAG ON THE RT ENG THAT WAS NOT AUTHORIZED FOR USE ON THIS ACFT & DID NOT PRODUCE SPARK DURING TEST.