Riding the Tomos the other day, I happened to look down at a stop light and saw a giant puddle of oil spreading out over the pavement. There was so much I thought surely it is from the Exxon Valdeez. Luckily I broke down close to Matt Smudge's work place, so I put my moped into his truck and he came outside and gave me a ride home. What caused the draining of transmission fluid? I thought the drain plug might have rattled loose. Nope, there was a hole in the bottom of the case. Suspiciously M6 size
The odd thing was there was also this nice little core of metal still sitting in the hole as the oil gushed out around it. It also was strange that it hadn't rattled lose and wasn't completely ejected by the whatever mystery force created it.
Opening up the transmission to see what decided to make the extra drain hole, I found this.
It's always nice when the cause problem is looking you right in the face. One of the cap screws that holds the case halves together worked its way out and dropped into the transmission, where it hooked onto one of the gears, and smashed into the case, bending the bolt and making the hole. The core of the hole fits very nicely against the cap screw, its kind of funny. So after a new case bolt with some loc-tite, I drilled the hole out, tapped it M6, and put in a short bolt with a bonded washer. I had never heard of these before, Naz turned me on to them. It's a snug fitting washer with some type of crush sealing rubber surface. I put that inside the case and turned a nut down on it, and no leaks of any kind. The Tomos lives again!
Interestingly enough, it's wrapped in a sweet plastic, encouraging you to insist on genuine Hero quality parts. 
The cylinder studs are square to each other, but a bit wonky on the orientation to the ports. I'd say the whole cylinder is is probably 6 degrees off. Curious if it will have any trouble bolting up to my pipe. 
