I apologize if this is old news but I didn't find anything on it. So I'll try and describe what I discovered on my own after much frustration. I probably wasted a couple hours this morning trying to get that pulley back far enough and my pry bar out of the way. I quit for a while and rang up my dealer. The guy that answered the phone at my dealer today didn't suggest this. He didn't know of any tricks. He just said it was sometimes difficult and you just need to keep trying. He also said it was easier with two people. Sure... isn't everything? My helper is 5 years old. So not much good advice.
But I had a brain storm after a while. And it worked....
here it is
1) Remove the belt covers. Clean out everything.
2) Reroute the lose belt onto ALL the deck pullies. Not on the motor pulley. Leave it off that for now.
3) Drop the deck down to mowing level to give yourself a little more room and lay down on the left side of the mower.
4) Take a 2 foot long pry bar and place it between the deck stud (you'll see it right in front of that rear idler pulley, the one without the spring attached to it) and the idler pulley, laying the pry bar right onto the belt that's already in the idler pulley's groove. All belts up on the deck should be in their groves right? Make sure now....
5) Pry back and route your bar over the primary pulleys bolt and nut.. and keep going past the tab or ear that holds that bolt that fastens the Black belt covers down. I removed the plastic nut for this. And carefully rest your pry bar behind that ear and bolt. So it jams in there and the tension of the idler spring holds it in place.
6) Now move to the rear of the mower and take a short (4-6 inch) screw driver ( I used a punch and probably a Phillips head would be best) and line up the belt to the rear (motor) pulley best you can and use your screwdriver (or some such short tool) and pry the last little bit of belt onto the pulley. You'll hear your pry bar that's jammed up front drop as the tension goes off of it as the belt goes on. No problem. Now wiggle your screw driver or punch out and presto. Your done.
Worked for me. Its kind of counter intuitive doing it this way but... it worked. And it allowed me to do it alone. My main point is to not try and both pry back the idler pulley AND thread the belt onto it. But to pry it back and affix it in that state and pry the belt on back at the motor. Which is counter intuitive to me but perhaps obvious to most of you out there. But here is another of those simple things that stares you in the face and should be easy and... actually turns out to be once you think outside the box. Sometimes you can get tunnel vision.
