72.5mm Big Bore Kit For CG250 CG350 ATV Dirt Bike Hawk TaoTao Apollo SSR

  
72.5mm Big Bore Kit For CG250 / CG350 Engine - ATV / Dirt Bike / Hawk / TaoTao / Apollo / SSR. This big bore kit is compatible with CG250 and CG350 series 4-stroke engines found in a wide range of ATVs, dirt bikes, dual-sport motorcycles, and utility vehicles. The following table lists vehicle models and brands where this kit is reported to be compatible. TBR7, DB14, DB17, ATA-250 series. Apollo 250cc dirt bike / ATV models. SSR 250cc dirt bike / ATV models. 250cc and 350cc CG-series 4-stroke engines. This kit is compatible with Zongshen CG250 engines and similar CG250 / CG350 brand engines using a 16mm wrist pin. It is also compatible with CG350 engines that share the same 72.5mm bore specification.

It is not compatible with Hawk 250 X-Pro models from 2023 and newer. Engines with a counterbalance shaft likely use a 15mm wrist pin and are not compatible with this kit. Confirm your engine uses a 16mm wrist pin before ordering. Complete top-end big bore rebuild kit - includes cylinder, piston, piston rings, pin clips, wrist pin, valve stem oil seals, exhaust gasket, and head gasket. Cylinder bore: 72.5mm - increases engine displacement from approximately 229cc to 268cc on CG250 engines.

Constructed with durable materials - intended to withstand increased heat and power output. Replacement for worn or damaged top-end components that may cause loss of compression, reduced power, or oil consumption. Increases Engine Displacement - The 72.5mm bore increases displacement from approximately 229cc to 268cc on CG250 engines, supporting improved power and torque. Restores Engine Performance - Worn cylinders and pistons can cause loss of compression and reduced power.

Replacing them with this big bore kit can help restore engine performance and responsiveness. Direct Replacement Fit - Manufactured to match the CG250 / CG350 engine specifications - installs without modifications in most cases. Some newer model CG250 engines may require minor machine work to the crankcase bore diameter. Complete Kit - Includes all necessary components for a top-end rebuild - reduces the need to source individual parts separately. Suitable for Multiple Applications - Compatible with Hawk, X-Pro, TaoTao, Apollo, SSR, CSC, and other CG250 / CG350-powered vehicles used for trail riding, off-road recreation, and dual-sport use.

Direct replacement - fits onto the existing crankcase and cylinder studs. Located at the top of the engine - access requires removing the cylinder head, cylinder, and piston. Basic hand tools are sufficient - a torque wrench is recommended for cylinder head bolts. Drain the engine oil before starting work.

Remove the cylinder head, old cylinder, and piston assembly. Clean the crankcase mating surface thoroughly before installing the new cylinder. Install the new piston onto the connecting rod with the new wrist pin and circlips - ensure the piston ring gaps are staggered correctly. Install the new cylinder over the piston - use a ring compressor tool to prevent ring damage. Install the new head gasket and cylinder head - tighten bolts to the torque specification listed in your service manual.

Reinstall the timing chain and adjust valve clearance according to the service manual. Refill with fresh engine oil and check for proper operation before riding. Professional installation is recommended if you are not experienced with top-end engine disassembly and reassembly procedures. Why Owners Consider This Replacement.

The CG250 and CG350 engine platforms are widely used in Chinese-brand ATVs, dirt bikes, dual-sport motorcycles, and utility vehicles from manufacturers such as Hawk, TaoTao, Apollo, SSR, and X-Pro. The top-end components can wear over time due to heat, friction, and normal use - leading to loss of compression, reduced power, and increased oil consumption. Rebuilding the top end with a big bore kit is a practical step that can help restore engine performance and increase displacement.

This 72.5mm kit offers a complete replacement solution for maintaining or upgrading your CG250 / CG350-powered vehicle. Package Includes: Cylinder, Piston, Piston Rings, Pin Clips, 16mm Wrist Pin, Valve Stem Oil Seals, Exhaust Gasket, Head Gasket.

Engine Compatibility: CG250 / CG350 4-stroke engines (Zongshen and similar brands).