Product Description
Keep your motorcycle's electrical system charging reliably with this genuine LiHua ZS300 Voltage Regulator Rectifier. Engineered specifically for 3-phase AC stator systems on 250cc–300cc engines (including the CSC Motorcycles SG250), this full-wave unit converts AC power from the alternator into steady DC voltage to safely charge your battery and run accessories without overloading your harness.
Key Technical Specifications & Features
- Brand / Manufacturer: LiHua (Logo cast directly on heat sink body)
- Model Code / Stamping: ZS300 | Rear Code:
250718T185| Cast Marking:N5 - System Type: 3-Phase Full Wave (DC output designed for "headlight always on" wiring setups)
- Connector Style: Dual nylon plug setup using standard 6.3mm (1/4") spade terminals:
- 3-Pin Plug (AC Input): Accepts 3 yellow wires from the stator.
- 3-Pin Plug (DC Output/Ground): Houses 1 red wire (positive), 1 green wire (negative) and 1 green/white wire (ground/reference).
- Body Dimensions (Standard ZS300 Heat Sink): ~80mm x 68mm (~3.1" x 2.8")
- Height / Thickness: ~28mm (~1.10")
- Mounting Hole Center-to-Center Spacing: ~55mm slotted centers (fits M6 mounting hardware)
- Harness Cable Length: ~150mm-180mm pigtail
Primary & Universal Fitment
Direct OEM Fit: CSC Motorcycles SG250 Cafe Racer.
Universal / Cross-Fitment: Compatible with many Chinese 200cc, 250cc, and 300cc air-cooled and liquid-cooled engines equipped with 3-phase stator outputs (such as Zongshen NC250/CB250, Loncin, Lifan, and CG/CB clone engines).
Note: Always verify connector plug style (3 yellow AC wires + Red/Green DC wires) and mounting hole spacing before ordering.
Function & How It Works
- Rectification: Converts high-voltage Alternating Current (AC) generated by the engine stator into Direct Current (DC) required by the battery and ignition electronics.
- Voltage Regulation: Discharges excess voltage above ~14.2V–14.7V as heat through the finned aluminum casing to prevent overcharging and electrical component failure.
Common Signs of a Failing Regulator Rectifier
- Dead or Drained Battery: The battery consistently loses charge during rides because the unit fails to pass charging current.
- Overcharging / Swollen Battery: System voltage spikes above 15V+, boiling the battery electrolyte, leaking acid, or blowing bulbs.
- Flickering or Dim Lights: Unstable DC output causes erratic headlight and instrument cluster brightness.
- Engine Misfires at High RPM: Inconsistent electrical output starves the ignition system under load.
- Overheating Casing: The outer body becomes excessively hot to the touch or exhibits a burning plastic odor.
