TrailMaster LK140 140cc 4-Stroke Dirt Bike

True Dirt-Bike Performance with Premium Alloy Components

The all-new TrailMaster LK140 brings true dirt-bike design and upgraded components to the TrailMaster lineup. Built around a reliable Yinxiang 140cc four-stroke engine, the LK140 combines electric and kick starting, four-speed gearing, inverted front forks, a nitrogen-filled rear mono shock, and oversized vented disc brakes for confident off-road performance.

Premium alloy components—including alloy rims, alloy hubs, foldable hand levers, and triple-tree clamps—give the LK140 a rugged, competition-inspired appearance while keeping the chassis equipped for demanding recreational trail riding.

Key Features

Yinxiang 140cc Four-Stroke Engine

The LK140 is powered by a single-cylinder Yinxiang engine designed for reliable off-road operation.

• 140cc displacement


• Single-cylinder, four-stroke design


• Air-cooled / oil-cooled system


• Maximum power: 6.8 kW @ 7,500 rpm


• Maximum torque: 9.7 N·m @ 5,500 rpm


• Compression ratio: 8.8:1


• CDI ignition


• Stainless steel muffler

Four-Speed Manual Transmission

A four-speed transmission and chain final drive provide direct control over the bike's power delivery.

• Four-speed gearing


• Non-circulating gear arrangement


• Chain drive


• Electric and kick start

Upgraded Alloy Components

The LK140 features numerous polished and lightweight alloy components throughout the chassis.

• Alloy front and rear rims


• Alloy hubs


• Polished alloy foldable hand levers


• Alloy upper and lower connecting boards


• Alloy handlebar components


• Upgraded hardware

Inverted Front Forks

The inverted front fork provides a sturdy front-end platform for off-road riding.

• Inverted front fork


• Non-adjustable design


• 17-inch front wheel


• 70/100-17 front tire

Nitrogen-Filled Rear Mono Shock

A nitrogen-filled rear mono shock works with the extended rear trailing-arm suspension design to help manage bumps and uneven terrain.

• Rear mono-shock suspension


• Nitrogen-filled shock


• Alloy U&D connector


• Extended rear trailing-arm design


• Non-adjustable rear shock

Oversized Vented Disc Brakes

The LK140 is equipped with oversized vented disc brakes at both ends to help manage heat during repeated braking.

• Front disc brake


• Rear disc brake


• Vented brake design


• Designed for improved stopping performance

Durable Steel Frame

A high-quality steel frame provides the foundation for the bike's off-road chassis.

• High-quality steel frame


• Rugged dirt-bike geometry


• Alloy chassis components


• Upgraded hardware

Stainless Steel Exhaust

The stainless muffler provides a durable exhaust component while complementing the sound and appearance of the Yinxiang engine.

Specifications

Engine & Performance

Specification	Details
Engine	Yinxiang 140cc
Engine Type	Single-cylinder, 4-stroke
Cooling	Air-cooled / Oil-cooled
Displacement	140 ml
Maximum Power	6.8 kW @ 7,500 rpm
Maximum Torque	9.7 N·m @ 5,500 rpm
Compression Ratio	8.8:1
Ignition	CDI
Starting System	Electric / Kick Start
Minimum Fuel Consumption	≤367 g/kW·h
Lubricant	SF15W/40
Exhaust	Stainless steel muffler

Transmission

Specification	Details
Shift Type	Four-speed, non-circulating gear
Final Drive	Chain Drive

Frame, Suspension & Brakes

Specification	Details
Frame	High-quality steel
Front Fork	Inverted, non-adjustable
Rear Shock	Nitrogen-filled mono shock, non-adjustable
Rear Suspension Connector	Alloy U&D connector
Upper/Lower Connecting Boards	Alloy
Front Brake	Disc
Rear Brake	Disc
Handlebar	Alloy
Hand Levers	Polished alloy, foldable

Wheels & Tires

Specification	Details
Rims	Alloy
Hubs	Alloy
Front Rim	17-inch
Rear Rim	14-inch
Front Tire	YUANXING 70/100-17
Rear Tire	YUANXING 90/100-14

Dimensions & Capacity

Specification	Details
Overall Dimensions	1780 × 740 × 1100 mm
Overall Dimensions	69.42 × 28.86 × 42.9 in
Wheelbase	1210 mm / 47.67 in
Seat Height	835 mm / 32.89 in
Ground Clearance	340 mm / 13.26 in
Fuel Capacity	6 L / 1.56 gal
Net Weight	78 kg / 171.6 lbs
Gross Weight	103 kg / 226.6 lbs

Packing & Shipping

Specification	Details
Packing Size	1370 × 440 × 660 mm
Packing Size	53.43 × 17.16 × 25.74 in
Net Weight	171.6 lbs
Gross Weight	226.6 lbs

Ideal Applications

• Recreational dirt-bike riding


• Off-road trails


• Private-property riding


• Dirt and mixed-terrain recreation


• Weekend trail adventures


• Riders looking for a true manual-shift dirt-bike experience

Rider Safety & Guidance

The TrailMaster LK140 is an off-road dirt bike intended for suitable riding environments. Riders should wear a properly fitted helmet, eye protection, gloves, boots, and appropriate protective riding gear.

Inspect the brakes, tires, wheels, chain, controls, suspension, and fasteners before each ride. Operate the bike only in areas where off-road riding is permitted and follow applicable local requirements.

Basic Care & Maintenance

• Check engine oil and maintain the recommended lubricant level.


• Inspect and lubricate the chain regularly.


• Check brake discs and braking components for wear.


• Inspect tire condition and inflation before riding.


• Check suspension components and mounting hardware periodically.


• Inspect alloy wheels, hubs, and fasteners for damage or looseness.


• Keep the air intake and engine area clean.


• Follow the manufacturer's recommended service intervals.

Why Choose the TrailMaster LK140?

The TrailMaster LK140 combines a 140cc Yinxiang four-stroke engine, four-speed manual transmission, inverted front forks, nitrogen-filled rear mono shock, alloy wheels and hubs, and front/rear disc brakes in a purpose-built dirt-bike package.

With premium alloy components, a high-quality steel frame, 13.26 inches of listed ground clearance, and a stainless steel muffler, the LK140 is designed to deliver a rugged and authentic off-road riding experience.

• We currently ship within the United States only.
• Enjoy free standard shipping on all orders.
• Orders are processed within 1–2 business days.
• Estimated Total Delivery Time is 4–7 business days.
• Tracking information will be sent to your email within 24 hours after your order has been dispatched.
• For more information about our shipping process, please view our full Shipping Policy.

• Not the right fit? Return or exchange within 30 days.
• Items must be unused and in original condition.
• Damaged products are eligible for a refund or replacement.Your line works well.
• For more information about our return & refund process, please view our full Return & Refund Policy.