I checked the mower and found that the belt came off only on the top pulley by the front wheels, likely knocked off by the lug nut wrench. I tried to pull it back on, but it was impossible. Following Russell King's advice, I removed the spring on one side and was able to pull the belt over the front pulley easily without removing the deck. This method only takes a couple of minutes.
While cutting the grass, when I made a turn in the opposite direction (perhaps too sharp, as I usually drive in one direction), the belt slipped off again, so I put it back on. After using the mower for an hour & driving more careful after the first incident, I lowered the cutting height for the 2nd. round.
Shortly after resuming, the belt slipped off again. This time the pulley was hot (from using) and the belt felt tight with less slack than before. Even after allowing the mower to cool down, I couldn't pull the belt over the pulley as easily as I had previously. Could anyone explain why this might be happening?
I also noticed the belt might be twisted and not properly seated in the groove as it should be (V-belt). This could be why the belt keeps slipping off. I tried to twist it back into place while reinstalling, but it was unsuccessful because the belt isn’t as slack as before and it's difficult to twist it back into the correct position.
Since I didn't remove the deck so I don't have the picture. I tried to remove the front tire for easy access to the front pulley but I can't simply pull the tire off. Do I need to use a hammer to knock it out? (pic 1 & 2).
I checked the blades, it's 21.5" Kubota blade (42" model), I have the problem of the grass uncut in the center like Mohawk hair after a guy sharpened the blades & installed it back 2 yrs ago. What did he do wrong? How to install the blades correctly? (pic 3 & 4). I might use the mower 10-20 hrs per year, or even less hours when I have a problem with the mower.
To remove the deck, do I simply pull out each pin at 4 locations--2 on each side (pic 5 & 6)?
For pic 5, which one is a better choice, pin 1 or 2?