NCY Performance AC CDI (No Rev Limiter) - GY6 & 139QMB
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Unlock your engine's full potential with the NCY Performance CDI. Designed specifically for 139QMB and GY6-based 50cc–170cc scooters, this high-output ignition module replaces your restrictive factory CDI with a more aggressive ignition curve and, most importantly, removes the factory rev limiter — allowing your engine to reach higher RPMs and sustain power through the top of the rev range.
Housed in a rugged orange billet aluminum casing, the housing doubles as a heat sink to protect the internal transformer, which boosts system voltage to 400–600 volts for a hotter spark and more efficient combustion.
Key Performance Benefits
- Rev Limiter Removed: Eliminates the electronic RPM ceiling found on stock units
- Aggressive Timing Map: Retuned ignition curve for improved acceleration and throttle response
- High-Voltage Output: 400–600V transformer boosts spark intensity for reliable ignition
- Billet Aluminum Housing: Protects sensitive electronics from road vibration and heat
Compatibility
This is a 6-Pin (2+4) AC Ignition module compatible with most Chinese-manufactured GY6 engines:
| Engine Family | Compatible Codes |
|---|---|
| 50cc / 80cc (139QMB) | 139QMA, 139QMB, 1P39QMB, 1P39QMA-2, YN139QMB, JJ1P39QMB, 139FMA-2 |
| 125cc / 150cc / 170cc (157QMJ) | 157QMJ, 161QMK, 152QMI, 1P61QMK, 1P57QMJ, 1P52FMI |
Don't see your engine listed? If the engine code includes "QM" or "FM" and uses an AC-based CDI system, this module is compatible.
Does NOT fit: Genuine 50cc scooters (Buddy/RoughHouse) or vehicles with DC-based ignition systems (e.g., Wolf Jet II).
Specifications
- Connector: 6-Pin (Square 2-pin + 4-pin block)
- Ignition Type: AC (Alternating Current)
- Voltage Output: 400–600V
- Manufacturer: NCY (ISO 9001 Certified)
- Weight: 0.29 lbs
About NCY
NCY is a Taiwan-based ISO 9001 certified manufacturer specializing in high-performance scooter components. Their CDI units are trusted by enthusiasts and tuners worldwide for consistent quality and measurable performance gains.
Safety & Legal: This product is intended for off-road/racing use only. Not legal for use on public roads. California residents: not legal for use on pollution-controlled vehicles. Performance upgrades are considered racing parts and are not covered under warranty.
Shipping information
Orders are prepared as quickly as possible. Delivery times and shipping costs are calculated at checkout based on the destination and items ordered.
Returns & warranty
Please verify fitment and part number before ordering. Contact Thrifty Scooters promptly if an item arrives damaged or incorrect.