39.0 mm piston with a rectangular piston ring with internal fuse (IS) suitable for Zündapp Belmondo mopeds, Zündapp Bergsteiger M25/M50 mopeds, as well as Alpa Spezial 3000 or Alpa Black River small motorcycles which have a Zündapp type 247 engine installed.
The detailed dimensions of the piston according to the technical drawing can be found in the details. You can also find out about the relevant piston rings, their stems and locking types on the legend in the pictures.
| Nominal diameter | 39 mm |
| Ø outside piston (A) | 38.96 mm |
| Compression height (C) | 26.3 mm |
| Curvature (D) | 1.3 mm |
| Total piston height (E) | 51.65 mm |
| Number of piston rings (F) | 1 pcs |
| Piston ring mold | Rectangular ring |
| Piston ring impact | Internal fuse (IS) |
| Ø piston pin (B) | 12 mm |
| Tolerance group | D |
| Weight piston kit | 84 g |
| Zündapp | Belmondo (Type 247-71) Moped 25 (M 25) / Moped M 50 Bergsteiger (Type 247-434) |
Accessories & related products
GPO piston pin extractor Ø 10, 12, 14 mm
Manufacturer: GPO · Diameter: 10 mm · Diameter: 12 mm · Diameter: 14 mm · Number of components: 7 pcs · Material: Steel · Surface: burnished · Area of application: (Dis)assembly tool · Total length: 130 mm · Width across flats: 10 mm · Width across flats: 17 mm
EUR 22.80
Meteor piston pin Ø 12 mm (length: 31 - 40 mm)
Manufacturer: Meteor · Material: Steel · Surface: Hardened · Total length: 31 mm · Total length: 31.5 mm · Total length: 33 mm · Total length: 35.5 mm · Total length: 37 mm · Total length: 38 mm · Total length: 40 mm · Ø piston pin (B): 12 mm · Pony OEM number: A1112 · Sachs OEM no.: 0216 003 105
EUR 7.90
Explore categories from Piston
Moped fans also bought
Carburetor 17 mm Bing SSB 1/17/69 reproduction
Height: 99 mm · Width: 86 mm · Camouflaged: No · Component group Carburetor: Carburetor complete · Material: Aluminum · Area of application: Standard · Area of application: Tuning · Carburetor type: SSB · Total length: 116 mm · Nozzle thread: MF7x0.75 (fine pitch thread) · Mounting type: Stud bolts & nuts · Nominal diameter: 17 mm · Hole spacing inlet: 31 mm · Ø fuel hose connection: 6.2 mm · Mixed oil connection: No · Vacuum connection: Yes · Choke control: without choke · Nozzle size: 76 · Clamping screw torque (max.): 3 N/m · Clamping screw torque (max.): 4 N/m
EUR 91.70
Loctite 243 medium-strength threadlocker 10 ml
Manufacturer: Loctite · Material to be used: Aluminum · Material to be used: Metal · Material to be used: Steel · Area of application: Chemistry · Contents: 10 ml · Color: blue · Hazard warning: Causes serious eye irritation · Hazard warning: Causes skin irritation · Hazard warning: Harmful to aquatic organisms (with long-term effects) · Hazard warning: May cause allergic skin reactions · Hazard warning: May irritate the respiratory tract · Signal word: Attention · Hazard pictogram: GHS07 - Caution dangerous · Hazard pictogram: GHS09 - Hazardous to the aquatic environment · Adhesion: medium strength · Temperature resistance (min.): -75 - 200 °C · Gap dimension (max.): 0.01 mm · Type of application: 1K · Alignment time: 600 sec · Breakaway torque (according to material): 3 N/m · Breakaway torque (according to material): 12 N/m · Breakaway torque (according to material): 26 N/m
EUR 25.10
EUR 2’510.00/l
swiing® revival gasket outlet | Zündapp Belmondo
Place of use: Outlet · Manufacturer: swiing® revival parts · Material: Graphite / Graphite · Ø inside: 25 mm · Total length: 53 mm · Ø outside: 38.3 mm · Thickness: 1.5 mm · Number of fixing points: 2 pcs · Ø mounting hole: 7.1 mm · Hole spacing: 40 mm
EUR 4.50
Spoke set incl. nipple (2.9 x 160 mm) galvanized steel
Nipple length: 15 mm · Material: Steel · Surface: galvanized (blue) · Quantity: 40 pcs · Length from hook: 160 mm · Ø spoke: 2.9 mm · Ø spoke head: 5.6 mm · Thread length: 11.5 mm · Nominal diameter (thread): 3.2 mm · Ø nipple head: 9 mm · Ø Nipple neck: 5.6 mm · Hook length: 10.3 mm · Hook angle: 95 °
EUR 43.50
Magneti Marelli SNA7 spark plug short thread
Manufacturer: Magneti Marelli · Candle designation: SNA7 · Candle thread type: short · Area of application: Tuning · Spark plug socket: M4 · Spark plug socket: SAE · Thread type: MF14x1.25 (fine pitch thread) · Electrode material: Nickel · Suppressed: No · Width across flats: 20.8 mm
EUR 9.05
Motorex ATF gear oil "Dexron III" 1 L
Manufacturer: Motorex · Oil type: ATF Dexron 3 (DEXIII) · Gearbox type: Automatic machine · Area of application: Gearbox lubrication with clutch · Hazard warning: Harmful to aquatic organisms (with long-term effects) · Contents: 1000 ml · Temperature resistance (min.): 170 °C
EUR 24.70
EUR 24.70/l
Attention: new opening hours from 16.02.2026 & new evening sale on Thursday 17:30-20:00
