Product Details
Description
Naraku 63cc (42mm) Replacement Piston for SYM 4-Stroke is a replacement piston assembly for compatible 139QMB scooter engine repairs or rebuilds.
Key Details
- NK101.66
Replacement Part Details
Use this part when the original component is worn, damaged, missing, or no longer working correctly. Many scooter parts can look similar but use different sizes, plugs, brackets, thread patterns, or mounting styles, so careful comparison before purchase is recommended.
Compatibility / Fitment
Use the fitment details below to confirm this part matches your scooter before ordering.
- Engine Size: 4-Stroke
- Engine Code: 139QMB
- Fits Models / Common Applications: SYM and other compatible models may apply.
Fitment Guide: This compatibility information is based on manufacturer and supplier data. Listed models are common known applications and may not include every compatible scooter. If your scooter has multiple versions or production changes, confirm the correct match before ordering. Check photos, measurements, original part numbers, engine code, model, and related fitment information whenever possible.
Common Fitment Questions
Q: Will this fit a 139QMB engine?
A: This SKU is listed as compatible with 139QMB engine-code fitment. Always compare your original part and scooter details before ordering.
Q: Will this fit a SYM?
A: This SKU is listed with SYM model fitment where the scooter also matches the listed engine or fitment notes.
Q: Is this for 4-Stroke scooters?
A: This SKU is listed with 4-Stroke engine-size fitment. Confirm exact model, year, and part style before ordering.
Additional information
| Weight | 0.3 lbs |
|---|---|
| Dimensions | 4 × 4 × 5 in |
This Naraku Piston Kit is compatible with engines running NK101.65 (42mm) SYM 4T cylinders, including Genuine and CSC 50cc scooters and other 50cc 4T 139QMB bikes.Â
- Piston Diameter: 42mm
- Wrist Pin Diameter: 10mm
- Includes piston rings and circlips
| Genuine Brio 50i | Genuine Urbano 50i |
| CSC Bella Classic 50 | CSC go |
| CSC go MAX | CSC Nitro Sport 50 |
| CSC Pug 50 | Â |
139QMB-based 50cc / 80cc engines with the following engine codes:
| 139QMA | 139QMB | 1P39QMB | 1P39QMA-2 |
| YN139QMB | JJ1P39QMB | 139FMA-2 | BD1P39QMB |
| BN139QMB | 147QMD | Other QMA models | Other QMB models |
Don't see your engine listed? If the engine code includes "QM" or "FM", this product is compatible with your vehicle.
About Naraku: NARAKU is a professional supplier of motorcycle parts from Taiwan. We’ve sold various motorcycle parts, scooter parts and accessories for more than 10 years. Our quality products are sold to Europe, Asia and America. We supply engine parts and accessories for modern scooters and mopeds. With our advanced technologies and the superb quality of our products, we can offer everything your ride needs.





