The following selection highlights five 150cc big bore and top-end upgrade kits designed for GY6 150cc engines and related Chinese scooters, ATVs, and go-karts. These kits aim to boost displacement, improve performance, and maintain OEM-like compatibility. Each entry lists core features to help you compare options for maintenance, repairs, or performance upgrades.
| Product | Brand | Key Benefit |
|---|---|---|
| 61mm Big Bore Cylinder Kit Upgrade | GOIRTUTSS Store | Increases displacement to 180cc with direct-fit compatibility |
| Complete GY6 Cylinder Head Rebuild Kit | Trkimal | Full head kit for 125/150cc engines |
| Tupo 150cc 57.4mm Top End Head Kit | Tupo Store | Comprehensive top-end upgrade for 157QMJ/152QMI |
| Tupo 150cc 57.4mm Big Bore Gasket Set | Tupo Store | Gasket and piston kit compatible with 76mm bolt pattern |
| 57.4mm Bore Complete Cylinder Rebuild Kit | GOIRTUTSS Store | All-in-one rebuild for multiple GY6 models |
61mm Big Bore Cylinder Kit Upgrade for GY6 150cc to 180/170cc
GOIRTUTSS’s 61mm bore kit is designed to upgrade GY6 150cc engines to about 180cc, with compatibility extending to Jog 50-100, CN/CF 250, and several 250-300cc machines. The package includes a 61mm bore cylinder, a 15mm piston pin, and a 69mm valve length. Features a corrosion-resistant coating and a direct-fit assembly that mirrors OEM specifications. A note mentions a slight tolerance of ±0.5–1mm due to manual measurements, which remains common in engine components. This kit targets riders seeking a straightforward upgrade path without major modifications.
Complete GY6 Cylinder Head Rebuild Kit
Trkimal’s rebuild kit centers on a 57.4mm cylinder bore with a non-EGR cylinder body. It provides full parts for motorcycle maintenance shops or DIY enthusiasts, including cylinder head components, gasket sets, and related hardware. The kit targets GY6 4-stroke engines around 125cc to 150cc used in many Chinese scooters, ATVs, and go-karts. The emphasis is on complete, affordable replacement parts that align with OEM standards for reliable restoration and performance restoration.
Tupo 150cc 57.4mm Top End Head Kit
Tupo’s top-end kit is designed for GY6 4-stroke engines (157QMJ 152QMI) and is compatible with Jonway, JM Star, Roketa, Sunl, Tank, Peace, Taotao, and similar Chinese scooters and ATVs. The package includes a cylinder, cylinder head, piston kit, piston rings, gasket set, valves, studs, fasteners, and a spark plug. Bolt-pattern compatibility is listed at 60mm and 76mm, and the kit excludes 80mm patterns. This bundle targets riders who want a comprehensive, pre-matched upgrade for increased displacement and improved performance while maintaining reliability.
Tupo 150cc 57.4mm Big Bore Gasket And Piston Kit
This gasket and piston kit from Tupo is designed for engines with a 76mm bolt pattern, explicitly noted as not compatible with 80mm patterns. It includes a cylinder, piston kit with rings, gasket kit, valve seals, intake and outlet studs, nuts, gloves, and a spark plug. Compatible with Jonway, JM Star, Roketa, Sunl, Tank, Peace, Taotao, and other Chinese scooters and ATVs. The solution suits users performing a mid-range rebuild with a focus on reliable sealing and engine top-end durability.
57.4mm Bore Complete Cylinder Rebuild Kit
GOIRTUTSS’s rebuild kit is designed for GY6 150cc engines within the 157QMJ/152QMI family. It includes a 57.4mm bore cylinder head, piston assembly, rings, wrist pin, gasket set, and hardware suitable for Taotao, Kymco, Baja, Sunl, Znen, and more. The kit emphasizes high-strength cast iron construction with corrosion-resistant finish and improved heat dissipation to handle heavy loads in four-stroke Chinese scooters, ATVs, and Go Karts. It provides a balanced blend of performance and durability for ongoing maintenance cycles.
Buying Guide
- Engine compatibility: Confirm your engine model (e.g., 157QMJ, 152QMI) and bolt pattern (60mm, 76mm, or 80mm) before choosing a kit. Mismatched bolts or cylinder bores can require additional machining or may not fit at all.
- Displacement goals: Decide whether you want a modest top-end boost or a full displacement increase (e.g., 180cc from 150cc). Larger bores may impact fuel economy and cooling needs.
- Top-end vs. full kit: Top-end kits (cylinder head, piston, rings) offer targeted performance, while full rebuild kits provide more components for a complete refresh and longevity.
- Materials and durability: Look for corrosion-resistant coatings and heat-dissipation features. Cast iron components tend to be durable but heavier than aluminum equivalents.
- Ease of installation: Some kits are direct-fit with minimal modifications; others require adjustments to gaskets, studs, or head height. Ensure you have the proper tools and torque specs.
- Support and warranty: Check for included hardware, gaskets, and instructions, as well as any manufacturer warranty or return policy.
- Maintenance implications: Upgrades can affect engine timing, compression, and fuel tuning. You may need to recalibrate carburetors or fueling settings for optimal performance.
- Use case: For street riding, prioritize reliability and heat management; for sport or go-kart use, you may favor higher displacement and performance parts with robust cooling.
Across these options, the emphasis is on compatibility with common GY6 150cc platforms and related Chinese scooters, ATVs, and go-karts. When selecting a kit, verify included components, bolt patterns, and whether the kit is designed for non-EGR or EGR engines, as this can influence performance and fit. Proper installation and break-in procedures are essential to achieve the intended improvements and avoid engine damage.