GOOFIT
63mm Big Bore Cylinder Kit with Rocker Arm & 94-Link Chain for 4-Stroke GY6 150cc 180cc 200cc Upgrade
63mm Big Bore Cylinder Kit with Rocker Arm & 94-Link Chain for 4-Stroke GY6 150cc 180cc 200cc Upgrade
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Product Overview
Push your GY6 engine to its absolute limit with the GOOFIT 63mm Extreme Big Bore Kit. This high-performance assembly is designed to transform standard 150cc engines into high-torque 180cc/200cc powerhouses. Unlike basic kits, this "Professional Series" includes a precision-matched rocker arm assembly and a heavy-duty 94-link timing chain to ensure your valve train can handle the massive increase in displacement. Perfect for off-road ATVs, high-speed scooters, and racing go-karts.
Product Compatibility
A premium performance upgrade for the GY6 150cc (157QMJ) platform and its high-displacement variants.
| Original Engine | Upgrade Potential | Recommended Application |
| GY6 150cc | Upgrades to 200cc | Racing Scooters & Quads |
| GY6 180cc / 200cc | Direct Replacement | High-Load Off-Road Use |
| Compatible Vehicles | ATVs, Go Karts, Buggies | TaoTao, Coolster, Ice Bear |
Specifications
| Attribute | Details |
| Cylinder Bore | 63mm / 2.48" (Extreme Big Bore) |
| Intake Port | Dia: 26mm (Bolt Spacing: 45mm) |
| Exhaust Port | Dia: 30mm (Bolt Spacing: 50mm) |
| Timing Chain | 94 Links (High-Strength) |
| Material | Aerospace-Grade Aluminum Alloy |
| Kit Includes | Cylinder, Rocker Arm Assembly, 94-Link Chain, Piston Kit, Gaskets |
Key Features
- Massive Displacement Boost: The 63mm bore provides a significant increase in raw horsepower and low-end torque, essential for heavy-duty off-roading and uphill climbing.
- Precision Rocker Arm Assembly: Includes a pre-adjusted rocker arm set that ensures exact valve timing and reduced friction, preventing "valve float" at high RPMs.
- Heavy-Duty 94-Link Timing Chain: Specifically selected for extended-deck or high-performance GY6 configurations, providing reliable synchronization between the crank and cam.
- Advanced Aluminum Heat Dissipation: The high-strength alloy body rapidly dissipates heat, maintaining engine stability and preventing power loss during long-distance, high-speed operation.
- Fuel-Efficient Power: Optimized combustion chamber design increases the compression ratio and combustion efficiency, delivering more "bang for your buck" with every drop of fuel.
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Fitment FAQ
Will this part fit my specific model and year?
This cylinder piston kit is intended for A premium performance upgrade for the GY6 150cc (157QMJ) platform and its high-displacement variants.; Original Engine; Upgrade Potential; Recommended Application; GY6 150cc; Upgrades to 200cc; Racing Scooters & Quads. Key physical/spec details from the product data include Cylinder Bore: 63mm / 2.48" (Extreme Big Bore), 63mm / 2.48" (Extreme Big Bore), Dia: 26mm (Bolt Spacing: 45mm). Use the compatibility table and product photos together before ordering.
Do I need to match the OEM part number?
Yes. If your original part has a stamped OEM or manufacturer number, match that number first before ordering. For this cylinder piston kit, also compare the bore diameter, piston-pin size, gasket pattern, stud spacing, engine code, stroke type, and cylinder height. This is especially important for GY6 GY6 models because similar model names can use different parts by year or trim.
What models or situations does this part not fit?
Do not order this cylinder piston kit for machines outside the listed compatibility, or for units with different bore sizes, piston-pin diameters, stroke lengths, stud spacing, or gasket patterns. Do not rely only on the model name or engine size.
What should I check before ordering?
Before ordering, compare your original part with the photos and check the bore diameter, piston-pin size, gasket pattern, stud spacing, engine code, stroke type, and cylinder height. Recheck listed specs such as Cylinder Bore: 63mm / 2.48" (Extreme Big Bore), 63mm / 2.48" (Extreme Big Bore), Dia: 26mm (Bolt Spacing: 45mm). If any connector, mounting point, size, or year detail is different, confirm fitment before installation.
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