18 HP Koehler command on a husqvarna YTH 18. All of a sudden it just stopped dead in its tracks, no noise, no smoke, no nothing.? Couldn’t turn the engine over at all. It’s like it seized up, took the spark plugs out and still could not get that crank to move. had a guy come out and look at it and he said it might be the electric clutch?? He said take the nut off at the bottom of the pulley and see if you can turn the engine that way if you can then it’s probably the electric clutch..when it goes bad it locks up the engine. Any thoughts??