GOOFIT
47mm Big Bore Cylinder Head with Valves & Gaskets for 4-Stroke GY6 80cc 139QMB 139QMA Engine (Non-EGR)
47mm Big Bore Cylinder Head with Valves & Gaskets for 4-Stroke GY6 80cc 139QMB 139QMA Engine (Non-EGR)
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Product Overview
Restore your scooter's compression and power with the GOOFIT 47mm Big Bore Cylinder Head. This high-toughness replacement head is specifically designed for upgraded 80cc GY6 4-stroke engines (139QMB/139QMA). Featuring pre-installed 20mm intake and 30mm exhaust valves, this Non-EGR assembly is built to withstand high temperatures while reducing friction and air leakage, ensuring your engine runs at peak efficiency.
Product Compatibility
This is a 47mm Big Bore specific head. It is not compatible with standard 39mm (50cc) cylinders unless you have already upgraded to an 80cc bore.
| Engine Type | Displacement | EGR Configuration |
| GY6 139QMB / 139QMA | 80cc (47mm Bore) | Non-EGR Only |
| Compatible Vehicles | ATVs, Go Karts, Scooters | TaoTao, Wolf, Ice Bear, Bacci |
Specifications
| Attribute | Details |
| Cylinder Inner Diameter | 47mm / 1.85" |
| Intake Valve Diameter | 20mm / 0.78" (Bolt Spacing: 45mm) |
| Exhaust Valve Diameter | 30mm / 1.18" (Bolt Spacing: 50mm) |
| Spark Plug Included | A7TC |
| System Type | Non-EGR (Standard) |
| Assembly Status | Completed with Valves & Springs |
Key Features
- Optimized for 80cc Performance: Specifically engineered for 47mm big bore cylinders to provide the correct combustion chamber volume and air-flow for 80cc power outputs.
- Pre-Installed Valve Train: Comes fully assembled with high-quality intake and exhaust valves, saving you the time and hassle of using a valve spring compressor.
- Non-EGR Simplified Design: Perfect for standard performance setups that do not use Exhaust Gas Recirculation, reducing complexity and potential leak points.
- High-Toughness Construction: Cast from premium alloys that are rustproof and corrosion-resistant, designed to maintain structural integrity under high thermal stress.
- Improved Gas Sealing: Includes a full set of high-performance gaskets to ensure a reliable, airtight seal between the cylinder head and the engine block.
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Fitment FAQ
Will this part fit my specific model and year?
This cylinder piston kit is intended for This is a 47mm Big Bore specific head . It is not compatible with standard 39mm (50cc) cylinders unless you have already upgraded to an 80cc bore.; Engine Type; Displacement; EGR Configuration; GY6 139QMB / 139QMA; 80cc (47mm Bore); Non-EGR Only. Key physical/spec details from the product data include 80cc (47mm Bore), Cylinder Inner Diameter: 47mm / 1.85", Intake Valve Diameter: 20mm / 0.78" (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 80cc (47mm Bore), Cylinder Inner Diameter: 47mm / 1.85", Intake Valve Diameter: 20mm / 0.78" (Bolt Spacing: 45mm). If any connector, mounting point, size, or year detail is different, confirm fitment before installation.