I ordered parts on internet to fix the engine (new carb jet, gaskets), fortunately I had another piston and cylinder, but I had to clean it. As the moped was temporary not functioning, I took advantage to clean it deeply.

The carb, cleaned with gasoline

I used the same brass jet from a propane blowtorch to fill the choke hole. I just soldered on the small hole with tin solder.

The piston, in very good shape once the carbon removed (soaked in gasoline for 2 days, it came apart easily).

Fresh piston rings.

I also had to adjust the gap of the piston ring. 0.2mm is perfect.

Using a needle file to slowly approach the desired gap.

Test with a thickness gauge, 0.1 should pass easy, 0.2 should pass with a little bit of resistance, and 0.3 shouldn't pass.

The two rings with the same gap.

The rings are set in place.

Rear sprocket cleaned!

I flushed the crankcase several times with gasoline to remove all the brass dust, I moved the connecting rod in case particles were trapped inside the bearings

I checked with a small flashlight, perfect. (the green liquid is 2 stroke oil) I used rubber bands to

secure the connecting to avoid shocks to the aluminium case.

The engine is now waiting for his reassembly, I should receive the gaskets in a couple of days.

See ya and sorry for my English, pretty sure I made a lot of mistakes ;)