I bought a used LZ27KC640, serial 406212. Before using the mower, I decided to replace all pulley's and belts on the deck and mule drive. However, the new mule belt is too long. I'm currently running a 6" pulley on both the right side adjustable pulley and left side spring pulley. I've adjusted the right side pulley all the way down. Still, the center of the spring bolt is slightly below the bottom of the alignment hole. More information: - I ordered all pulley's using exmark part numbers. - The pulley's I received are the same size as the pulley's I removed. - The spring idler pulley I received is about 5"...but, as noted above, I put on an old 6" pulley in an attempt to get the belt tight. - The clutch pulley appears to be about 6.5" in diameter. Any advice appreciated.