RDLN Performance Camshaft A9; 139QMB
RDLN A9 Performance Camshaft – GY6 50cc / 139QMB (High-Lift)
$29.41
10 in stock
*Note: Free shipping to U.S. mainland (excludes AK, HI, and territories)
Orders placed by 1pm EST on weekdays ship the same day.
Product Details
Description
RDLN A9 Performance Camshaft – GY6 50cc / 139QMB (High-Lift)
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, GY6
- Engine Code: 139QMB
- Fitment Notes: Performance
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 | 0.6 lbs |
|---|
| Condition | New |
|---|
Transform your scooter's power band with the RDLN A9 High-Lift Performance Camshaft. Designed specifically for the GY6 50cc (139QMB) platform, the A9 profile is the industry standard for increased performance. By increasing valve lift and extending duration, this camshaft allows your engine to breathe deeper at high RPMs, delivering a significant boost in mid-range torque and top-end speed. Ideal for engines equipped with 72cc–100cc big bore kits.
Model Compatibility
Compatible with 139QMA / 139QMB engine heads found on nearly all 4-stroke 50cc Chinese scooters:
- 139QMA | 139QMB | 1P39QMB | 1P39QMA-2
- YN139QMB | JJ1P39QMB | 139FMA-2 | BD1P39QMB
- BN139QMB | 147QMD | Other QMA and QMB variants
Don't see your engine code? If your 49/50cc 4-Stroke engine code includes "QM" or "FM", this camshaft is likely compatible.
Key Features
- A9 High-Lift Profile: More aggressive lift than stock for maximum air/fuel intake — ideal for big bore 72cc–100cc builds.
- Pre-Installed Bearings: High-speed, low-friction steel bearings pre-fitted for smooth rotation and long-term reliability under high-heat conditions.
- Hardened Steel Alloy: CNC-machined from high-carbon steel alloy to prevent lobe wear and pitting over time.
- Drop-In Installation: Direct replacement for the stock 139QMB camshaft — no head machining required for standard applications.
Technical Specifications
- Intake Lobe: 26.50mm (±0.05mm)
- Exhaust Lobe: 26.35mm (±0.05mm)
- Material: Hardened steel alloy
- Bearings: Pre-installed 16002/P6 rated ball bearings
- Certification: ISO 9001
- Includes: Complete camshaft with pre-installed bearings
Tuning Tip: To fully realize the gains of the A9 camshaft, pair it with a high-flow intake manifold and slightly stiffer valve springs. Always re-adjust valve lash to .004" (0.10mm) for both intake and exhaust after installation.
Off-Road Use Only: This product is intended for off-road/racing use only. Not legal for use on public roads or on pollution-controlled vehicles in California. Performance upgrades are not covered under warranty.
