1. Introduction
This manual provides essential information for the proper installation, operation, and maintenance of your LiFuJunDong 125CC 1P52FMI 4-Stroke Engine Motor. Please read this manual thoroughly before attempting any procedures to ensure safe and efficient use of the product. This engine is designed for various applications, including compatibility with models such as H-on-da CRF50, CRF70, XR50, XR70, Z50, Z50R, CT70 Mini Trail, Minitrail Monkey, XL70 ST70, QA50, QR50, CL70, SL70, 70 Passport, ST 90K2, ST 90K1, CS 90, SL 90, and ZB 50.
Image 1.1: Side view of the LiFuJunDong 125CC 1P52FMI 4-Stroke Engine Motor, showcasing its compact design and air-cooled cylinder head.
2. Safety Information
Warning: Professional installation is strongly recommended for this engine. Improper installation can lead to serious injury or damage to the product and vehicle. Always wear appropriate safety gear, including eye protection and gloves, when handling or working with the engine.
- Ensure the engine is cool before performing any maintenance or adjustments.
- Keep hands, feet, and clothing away from moving parts.
- Operate in a well-ventilated area to avoid inhaling exhaust fumes.
- Always disconnect the spark plug wire before performing any service to prevent accidental starting.
- Refer to your vehicle's specific service manual for additional safety precautions related to engine replacement.
3. Package Contents
Verify that all components listed below are present in your package. If any items are missing or damaged, please contact the seller immediately.
Image 3.1: Overview of all components included in the package, featuring the engine, carburetor, CDI, and various levers and gaskets.
- 1x 125CC 1P52FMI Engine
- 1x Kick Starter Lever
- 1x Gear Shift Lever
- 1x Carburetor (PZ16J Type)
- 1x Intake Manifold
- 1x CDI (Capacitor Discharge Ignition)
- 2x Intake Gaskets
- Screws (for mounting)
- Sprocket Cover
Image 3.2: Detailed diagram illustrating the dimensions of the engine (42.5cm/16.73in length, 27cm/10.63in height) and identifying key included components like the gear shift lever and kick starter lever.
4. Specifications
Detailed technical specifications for the 125CC 1P52FMI engine motor:
| Specification | Value |
|---|---|
| Manufacturer | LiFuJunDong |
| Model Number | CXN001 |
| Engine Type | Single cylinder, 4-stroke, air-cooled |
| Bore × Stroke | 52.4 × 55.5 mm |
| Displacement | 119.7 ml |
| Compression Ratio | 9.0:1 |
| Minimum Fuel Consumption | ≤367g/kw.h |
| Ignition System | CDI |
| Start Mode | Kick-starter |
| Spark Plug | A7TC |
| Clutch | Wet multi-plate, manual operation |
| Transmission | 4-speed |
| Carburetor Type | PZ16J |
| Primary Reduction Ratio | 3.722 |
| Gear Ratios | 1st: 2.833, 2nd: 1.706, 3rd: 1.238, 4th: 0.958 |
| Lubricant Capacity | 900 ml |
| Recommended Lubricant | SAE15W/40-SE, 4-stroke gasoline engine oil |
| Maximum Power | 6.5 kW/7500r/min ±375r/min |
| Rated Power | 5.6 kW/7500r/min ±375r/min |
| Maximum Torque | 8.0 Nm/5000r/min ±250r/min |
| Idle Speed | 1500r/min ±100r/min |
5. Setup and Installation
Installation of this engine requires mechanical knowledge and appropriate tools. If you are not confident in your ability to perform the installation, it is highly recommended to seek assistance from a qualified professional.
5.1 Pre-Installation Checks
- Inspect all components for any signs of shipping damage.
- Ensure all necessary mounting hardware and accessories for your specific vehicle model are available. Note that this engine may require additional components such as a clutch cable, perch, air filter, and throttle cable depending on the original vehicle setup.
- Verify compatibility with your vehicle frame and mounting points. Some older H-on-da models (pre-1970s) may require adapter kits for engine mounts.
5.2 Installation Steps (General Guidelines)
- Mount the Engine: Securely attach the engine to the vehicle frame using appropriate bolts and brackets. Ensure proper alignment.
- Install Carburetor and Intake Manifold: Attach the intake manifold to the engine cylinder head using the provided gaskets, then mount the carburetor to the intake manifold. Ensure all connections are tight to prevent air leaks.
- Connect Electrical Components: Connect the CDI unit and other electrical wiring. A wiring harness may be required, as the engine ships with basic wiring for the CDI. Consult a wiring diagram for your specific vehicle if available.
- Install Levers: Attach the kick starter lever and gear shift lever to their respective shafts on the engine.
- Lubrication: Fill the engine with 900 ml of SAE15W/40-SE 4-stroke gasoline engine oil. Do not overfill.
- Fuel Connection: Connect the fuel line from the vehicle's fuel tank to the carburetor.
- Exhaust System: Connect the exhaust pipe to the engine. Ensure a proper seal.
Important: This engine features an air-cooling system designed to prevent overheating and ensure smooth operation. Ensure adequate airflow around the engine once installed.
6. Operation
Before starting the engine, ensure all connections are secure, the oil level is correct, and there is sufficient fuel in the tank.
6.1 Starting the Engine
- Turn the fuel valve to the 'ON' position.
- If the engine is cold, engage the choke on the carburetor.
- Ensure the transmission is in neutral. The engine may not start if a gear is engaged, even with the clutch pulled.
- Use the kick-starter lever with a firm, swift motion. Repeat until the engine starts.
- Once the engine starts, gradually disengage the choke as the engine warms up.
6.2 Shifting Gears
This engine features a 4-speed manual transmission with a wet multi-plate clutch. Operate the clutch lever smoothly when shifting gears. The gear pattern is typically 1-N-2-3-4 (all up or 1 down, 3 up). Finding neutral can sometimes be challenging, especially during the break-in period or while the engine is running.
7. Maintenance
Regular maintenance is crucial for the longevity and optimal performance of your engine.
7.1 Oil Change
- Change the engine oil after the first 20 hours of operation (break-in period), and then every 50-100 hours or as recommended by your vehicle's manual.
- Use SAE15W/40-SE 4-stroke gasoline engine oil.
- Ensure the engine is warm before draining the oil for better flow.
- Refill with 900 ml of fresh oil.
7.2 Spark Plug Inspection
- Inspect the A7TC spark plug periodically for wear, fouling, or incorrect gap.
- Clean or replace the spark plug as needed to ensure efficient combustion.
7.3 Air Filter Maintenance
- Regularly clean or replace the air filter element to prevent dirt and debris from entering the engine. A clogged air filter can reduce performance and engine life.
7.4 General Inspection
- Check all bolts and fasteners for tightness.
- Inspect fuel lines and electrical connections for wear or damage.
- Ensure the clutch cable has proper free play.
8. Troubleshooting
This section addresses common issues you might encounter with your engine. For problems not listed here, or if solutions do not resolve the issue, please contact customer support.
| Problem | Possible Cause | Solution |
|---|---|---|
| Engine does not start | No fuel, fouled spark plug, no spark, engine not in neutral, incorrect choke setting. | Check fuel level and flow. Inspect/replace spark plug. Verify CDI connection and spark. Ensure transmission is in neutral. Adjust choke. |
| Engine runs poorly/lacks power | Clogged air filter, dirty carburetor, incorrect fuel mixture, old fuel, improper valve clearance. | Clean/replace air filter. Clean carburetor. Use fresh fuel. Consult a professional for valve adjustment. |
| Difficulty finding neutral | New engine (break-in period), clutch adjustment, internal transmission issue. | This can be common with new engines. Ensure clutch is properly adjusted. If persistent, professional inspection may be needed. |
| Oil leaks | Loose bolts, damaged gaskets, overfilling oil. | Check and tighten all engine casing bolts. Inspect and replace any damaged gaskets. Ensure oil is filled to the correct level. |
| Excessive smoke from exhaust | Burning oil, rich fuel mixture. | Check oil level (do not overfill). Inspect piston rings and valve seals. Adjust carburetor. |
9. Warranty and Support
For any questions, technical assistance, or warranty claims, please contact the seller directly. It is recommended to have your purchase details and model number (CXN001) available when contacting support.
If you encounter installation problems or have not received complete instructions, please contact the seller first for guidance.
Manufacturer: LiFuJunDong