56mm Engine Cylinder & Piston Rebuild Kit for YX140 1P56FMJ 140cc 150cc Dirt Pit Bike ATV

Product Overview

Unlock the raw power of your YX engine with the GOOFIT 56mm Cylinder Rebuild Kit. Engineered specifically for the YX140 (1P56FMJ) and compatible 150cc oil-cooled horizontal engines, this kit is designed to restore lost compression and maximize torque. With an optimized combustion chamber profile and high-temperature stable materials, it delivers a significant boost in throttle response and overall mechanical reliability for your pit bike or quad.

Product Compatibility

This 56mm kit is a high-performance replacement for YX (YinXiang) style horizontal engines.

Engine Model	Displacement	Vehicle Type
YX140 / 1P56FMJ	140cc	Dirt Bikes, Pit Bikes
Compatible Horizontal	150cc Variants	ATVs, Quads, Karts
Piston Style	56mm Bore	High-Compression Ready

Specifications

Attribute	Details
Cylinder Inner Diameter	56mm / 2.2"
Engine Code	YX140 / 1P56FMJ
Engine Type	4-Stroke Oil-Cooled / Air-Cooled
Displacement	140cc - 150cc
Package Includes	Cylinder, Piston, Rings, Pin, Clips, Gaskets

Key Features

• YX140 Precision Fit: Tailor-made for the 1P56FMJ engine series, ensuring perfect oil passage alignment and deck height for optimal valve-to-piston clearance.
• Enhanced Compression Ratio: Featuring an optimized piston and combustion chamber design that improves thermal efficiency, resulting in more explosive power and a smoother RPM curve.
• Superior Thermal Stability: Constructed from advanced alloys with excellent corrosion resistance, this kit maintains structural integrity even under the high-stress conditions of off-road racing.
• Rigorous Quality Testing: Every cylinder undergoes strict dimensional inspection and leak testing to ensure "out-of-the-box" reliability and consistent performance.
• Optimized Scavenging: The precision-honed cylinder walls facilitate superior oil film retention and piston ring sealing, reducing blow-by and extending engine life.