This is a quick overview on how to take a Honda PA50 or PA50 II final drive apart. Skill level required 3/10 Tools required - Nothing special... 14mm wrench (oil drain plug) 10 or 12mm for arm, screwdriver #3 I think, Mallet, vice, torch for bearing removal.
You have to remove the rear wheel from the hobbit subframe. Quick overview - 4 bolts on final drive ( 2 have nuts, 2 have them built into the rear drive ), remove the tensioner for the chain, remove the belt --- it should be simple!
Now you have a big wheel with the final drive. Hammer on that 7/8 12pt socket, impact it off with hand on the wheel / rim. slide the break hub off, now your getting there.
Drain Oil, remove 14mm bolt in the middle of the housing
Unscrew the 5 screws, I used my craftsman screwdriver, with basically a JIS plus head on it. Not really a Phillips. I had to use the blk wrench to get torque on it!
Scribed a line for the position of the arm and remove the arm, I guess you want it in 'Neutral' , flipped toward the ground when mounted to the moped
So you have the bolts removed and the arm, you also need to remove the rear pulley. I would use a strap wrench on the thing. I didn't snap a picture.
Now you need to separate the halves. To crack it apart, you gotta hit it. Maybe rubber mallet. I only got some wood material, worked for me. Clamped it in a vice on one of the bolt tabs. Back and fourth a few times and had no problems.
Weather I forgot a step or not, this is what you get. A couple washers in there, and some shafts/gears that sit in their own spaces!
One side of the case, lots of oil
So at this point you may as well remove the bearings and replace them. Its cool with me! Heat up the inside, or outside of the case, smack them to the inside, done.
2 x Small washer @ 94/95mm thick, OD 18.6, ID 10.34
1 x Large Washer @ 98mm thick, OD 27.92, ID 17.16
These are the Honda OEM parts for the seals and bearings. Yours may or may not need replaced. Check your local honda dealer for bearings, or order them yourself from a trustworthy shop. Oil seal dimensions are in metric (e.g. "24X34X5.5" means 24mm inner diameter, 34mm outer diameter, 5.5mm thick)
For the pulley side,
BEARING (6201) 96100-62010-00 OIL SEAL (12X22X5) 91201-965-000
For the brake side,
BEARING (6203) 96100-62033-00 OIL SEAL (24X34X5.5) 91203-148-003
There are two of these needle bearings on the gearshafts:
BEARING (1010) 91021-148-004