Rebuilding piaggio Ciao px moped
Over the summer of 2025 while working in Sweden, I worked on an old 1982 Piaggio Ciao PX moped, nicknamed “Luigi”, handed down from my uncle because it was no longer starting. I began with running some tests to see if a spark was generating in the combustion chamber where I pulled out the spark plug and held it against the engine block (a grounded metal) to see if an arc was generated. I had my brother try to pedal start with the moped lifted and saw no arc. Therefore I turned my attention towards the drivetrain, since the stator is driven by the crankshaft, which generates the current for the spark plug.
When pedaling and trying to start with a running start, I realized that no matter how fast the wheel spun the secondary clutch would not engage. After disassembling the clutch pack I found worn out springs, disks, clutch shoes, and the inside of housing smooth. I ordered the necessary parts and modified the ones I could, such as roughing up the clutch housing again without taking off too much material. I was able to get the moped working and even rode it on my 20 km journey to work in the mornings. By the end of the summer it was difficult to start again and I was able to continue the adjust the clutch packs to get Luigi to start a few more times, but it got more and more difficult. The stator and converter might need to be looked at hopefully next summer to restore its starting prowess, and I also have ambitions to swap the engine.
Fig 1. Picture of me taking off to work with the moped up and running

Fig 2. Picture of end of the drivetrain where the clutch connects to the final drive; can see the axel wheel hanging on the belt driver, which is connected to the rusted drive clutch

Fig 3. Diagram of how the clutch packs worked in series

Fig 4. Worn out rear driven pulley that had hopped out of its slot and the shaft had torn away the material on the inside of the key slot