C90 90cc Cylinder Assy

C90 Cast Iron Cylinder Assembly

For Moped, Cub, Dirt Bike & ATV

Fits Engines: 139FMB 147FMD 147FMF 150FMG

Material: High-Quality Cast Iron Cylinder — Complete assembly includes cylinder block, piston, piston rings, and pin

This product is a C90 series cast iron cylinder assembly, designed for horizontal engines used in mopeds, Cub motorcycles, dirt bikes, and ATVs. It perfectly fits classic engine models such as 139FMB, 147FMD, 147FMF, and 150FMG. The cylinder block is manufactured from high-quality cast iron, offering excellent wear resistance, good thermal stability, and a long service life. The piston is made of premium aluminum alloy. All components are produced to OEM specifications, ensuring perfect compatibility with your engine.

This cast iron cylinder assembly is primarily compatible with the following horizontal engine series:

• Quality Cast Iron Cylinder: Made of high-quality cast iron, offering excellent wear resistance and resistance to thermal deformation for long service life.
• Precision Honed Bore: The cylinder bore is precision-honed to create a cross-hatch pattern for oil retention, aiding piston ring break-in and lubrication.
• Complete Assembly: Includes cylinder, piston, rings, and pin - one-stop purchase with no need for separate matching, ensuring perfect component compatibility.
• OEM Specifications: Manufactured to original dimensions for direct replacement with perfect fit.
• Two Displacement Options: Available in 70/90cc and 110cc sizes to meet different engine repair needs.

✅ Typical Symptoms of Cylinder Wear or Damage: Hard starting, significant power loss, burning oil (blue smoke from exhaust), low compression, unusual engine noises (knocking or pinging). If you experience these issues, the cylinder assembly may need replacement.

⚠️ Installation Note: When replacing the cylinder assembly, it is recommended to also replace the cylinder head gasket. Clean the crankcase mating surface thoroughly and tighten the cylinder head bolts to the specified torque and sequence as per the service manual. Cast iron cylinders are relatively heavy, so ensure proper support during installation. When installing the piston, note the direction (arrow usually points to exhaust side). Stagger piston ring end gaps. Allow proper engine break-in after installation.