The Max Trading engine comes with a complete set of accessories at the factory, including foot start components, shift lever, intake pipe, sealing gasket, and a full set of bolts. No additional accessories are required and can be installed and used directly. The YX140 140cc Complete Pit Bike Engine 4‑stroke Manual Clutch adopts a foot start mode and a manual four speed transmission design, with sensitive and smooth handling, clear shifting, and meeting the needs of daily cycling and vehicle modification and upgrading.
As a popular overseas modification YX140 1P56FMJ engine, this 140CC four stroke single cylinder 140cc 4 stroke oil cooled engine is specially designed for off‑road conditions, optimizing the shortcomings of traditional air‑cooled engines. Professional grade oil cooled cooling structure, combined with pressure&splash lubrication system, can quickly remove the high temperature generated by high load operation. A stable heat dissipation and lubrication system ensures that the engine maintains good working conditions during long‑term off‑road riding, track racing, and sustained high‑speed operation.
1.2 Golden power parameters with gear adjustment, balance performance
This dirt bike off‑road engine has technical power parameters, with a maximum power of 7.0 kw and a maximum torque of 9.5 N. m. It is equipped with a 2‑valve precision intake structure and an 8.8:1 scientific golden compression ratio, providing strong starting power and smooth acceleration. At the same time, the YX140 140cc Complete Pit Bike Engine 4‑stroke Manual Clutch comes standard with a 4‑speed manual clutch manual four speed transmission structure, with clear gear division, smooth shifting connection, sensitive clutch control, and no lagging or disengagement phenomenon.
This horizontal 140cc engine is compatible with the original CRF50 and XR50 pit bike frames, and is suitable for the power modification and old engine replacement scenarios of most small off‑road motorcycles and pit bikes on the market. The body size is regular and the hole positions are precisely aligned with industry standards, making it the preferred pit bike replacement engine for niche car modification and old car replacement.
YX140 140cc Complete Pit Bike Engine 4‑stroke Manual Clutch supports direct bolt‑on replacement installation. The entire machine is equipped with a complete set of accessories at the factory, including foot start components, shift lever, dedicated intake pipe, sealing gasket, and a full set of fixing bolts. The customer does not need to purchase additional spare parts after receiving the complete machine.
This YX140 140cc pit bike engine is equipped with a mature and stable 1P56FMJ original factory standard configuration, which is a complete integrated assembly from the factory. Unlike the low‑priced models on the market that are heavily reduced, refurbished, and assembled, this engine has significantly improved overall durability in terms of hardware structure, and has a stable and controllable reputation at the end.
In response to the needs of cross‑border trade and overseas users, the YX140 140cc Complete Pit Bike Engine 4‑stroke Manual Clutch adopts a lightweight overall design, with a net weight of only 23KG. It is equipped with a compact standardized packaging size of 500 × 400 × 350mm, which is small in size and easy to handle, effectively reducing international logistics freight and overseas warehousing and stacking costs.
| Name | YX140 140cc Complete Pit Bike Engine 4‑Stroke Manual Clutch | Category | Motorcycle engine assembly |
| Model | 4‑stroke, aluminum single cylinder, 2‑valve, oil cooled, horizontal engine | Startup Method | Foot activation |
| Clutch mode | Manual clutch | Gear | 0‑1‑2‑3‑4 four speed transmission |
| Cylinder diameter x stroke | 56mm×57mm | Compression ratio | 8.8:1 |
| Maximum net power | 7.0kW / 8500r/min | Maximum Torque | 9.5N・m / 5500r/min |
| Lubrication method | Pressure+splash composite lubrication | Supporting attachments | Foot starter assembly, shift lever, intake pipe, sealing gasket kit, complete set of bolts |
| Net weight | 23KG | Outer packaging dimensions | 500×400×350mm |
Clean the installation position of the frame, confirm the compatibility with the CRF50/XR50 frame, and check the status of the entire machine and accessories
Prepare basic disassembly and assembly tools to ensure that the vehicle is powered off and the body is fixed
Line with the YX140 horizontal engine with the mounting holes on the frame and insert it accurately
Insert the matching fixing bolts and tighten them diagonally in stages
Install the matching intake pipe and sealing gasket, and connect them tightly
Assemble the gear shift lever and foot start component, adjust the gear position (0‑1‑2‑3‑4), and ensure smooth gear shifting
Connect the oil circuit, electrical circuit, and clutch cable, adjust the clutch clearance to ensure sensitive operation
Add suitable engine oil, attain the machine pressure and splash lubrication requirements, and check the oil level standard
Double check all bolts, pipelines, and interfaces to confirm that there is no looseness or missing installation
Start the ignition with your feet, idle for 3‑5 minutes, and check for any unusual noise, oil leakage, or high temperature on the body
Low speed test drive, the gear shift, clutch, and power output status, and if there are no errors in adjustment, it can be used normally
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