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.
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