Rocker Arm Assembly (Type 1, 64mm); 139QMB
Rocker Arm Assembly (Type 1, 64mm); 139QMB
$32.58
Out of stock
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Product Details
Description
Rocker Arm Assembly (Type 1, 64mm); 139QMB
Compatibility
Fits many 139QMB-based 50cc / 80cc scooter engines. Confirm measurements, connector style, and engine family before ordering.
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: 50cc, 80cc
- Engine Code: 139QMB
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: Is this for 50cc scooters?
A: This SKU is listed with 50cc engine-size fitment. Confirm exact model, year, and part style before ordering.
Additional information
| Weight | 0.5 lbs |
|---|---|
| Dimensions | 4 × 3 × 2 in |
Keep your 139QMB engine running smoothly with this OEM two-valve rocker arm assembly from Blue Line Designed specifically for Type 1 engines with 64mm valve stems and a shorter cylinder head, this is a direct-fit replacement that restores proper valve actuation and engine timing without modification.
Not sure which type you have? Type 1 engines have 64mm valve stems and a shorter head. If your valve stems measure 69mm with a taller cylinder head, you have a Type 2 engine (made by Zhejiang ZhongNeng / ZNEN) — this assembly will not fit Type 2 engines.
Key Features
- OEM Direct Fit: Exact replacement for Type 1 139QMB engines — no modification required.
- Complete Assembly: Includes rocker arm holder, inlet and outlet shafts, two rocker arms, two tappets, and two nuts.
- Precision Tolerances: Machined to OEM specifications for reliable valve timing and long service life.
- Broad Engine Compatibility: Fits all QMA/QMB engine codes with Type 1 head configuration.
Technical Specifications
- Rocker Arm Holder: L: 66mm / W: 66mm / H: 26mm / Holes: 7.4<9mm / Spacing: 50mm
- Shaft Inlet: L: 51.3mm / OD: 8.8<12.9mm / ID: M5
- Shaft Outlet: L: 43.5mm / OD: 10mm / ID: M5
- Rocker Arms (x2): L: 52.7mm / W: 22.2mm / H: 18.6mm
- Tappets (x2): L: 18.53mm / OD: M5x0.5mm
- Nuts (x2): L: 4.2mm / ID: M5x0.5mm / OD: 9mm
CSC Model Compatibility
| Model |
|---|
| CSC Bella Classic 50 |
| CSC Nitro Sport 50 |
| CSC Pug 50 |
| CSC go |
| CSC go MAX |
139QMB Engine Code Compatibility
Fits 50cc and 80cc engines with the following engine codes (Type 1 head only):
| Engine Codes |
|---|
| 139QMA Â |Â 139QMB Â |Â 1P39QMB Â |Â 1P39QMA-2 |
| YN139QMB Â |Â JJ1P39QMB Â |Â 139FMA-2 Â |Â BD1P39QMB |
| BN139QMB  | 147QMD  | Other QMA models  | Other QMB models |
Â
Don't see your engine code? If it includes "QM" or "FM" and you're running a 139QMB Type 1 engine, this part is compatible.
