38 mm replacement piston with two rectangular piston rings with flank lock (FS) suitable for blown Sachs 50/3, 50/4 mopeds / mopeds with reproduction cylinders such as our GPO Wummer.
The detailed dimensions of the piston according to the technical drawing can be found in the details. You can also find out about the common piston rings, their stems and locking types on the legend in the pictures.
| Manufacturer | GPO |
| Nominal diameter | 38 mm |
| Ø outside piston (A) | 37.94 mm |
| Compression height (C) | 27.5 mm |
| Curvature (D) | 3.5 mm |
| Total piston height (E) | 53 mm |
| Number of piston rings (F) | 2 pcs |
| Piston ring mold | Rectangular ring |
| Ø piston pin (B) | 12 mm |
| Piston ring impact | Flank safety device (FS) |
| Piston ring height | 1.7 mm |
| Thick piston ring | 2 mm |
| Weight piston kit | 78 g |
| Alternative version of the Sachs OEM number | 0290 058 025 |
| Sachs | 50/3 50/4 - MLFB (2.6 PS) , LKH (4.5 PS) |
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