GY6 61mm 171cc No-Cut Big Bore Kit
ITEM# TT-26754
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Description
61mm Big Bore Upgrade for GY6 125cc and 150cc Motors
This 61mm big bore setup raises the displacement of supported four-stroke GY6 125cc and 150cc engines to roughly 171.3cc. It bolts in without any modification to the engine case, which makes it a practical pick for riders wanting more pull and power. Among GY6 scooter parts, it is a straightforward way to improve acceleration. Everything needed for the install comes in the box, so it suits both experienced builders and home mechanics.
Build Quality and Included Parts
The cylinder is cast from aluminum, a material that moves heat away well. The piston uses a short-skirt design, which cuts down on reciprocating weight and helps the engine respond more quickly. The package covers the cylinder, piston, compression rings, wrist pin, fasteners, and gaskets, so you have what you need for a complete fitting.
Engine Match and Compatibility
This kit is built for GY6 125cc–150cc four-stroke engines stamped with QMI or QMJ codes. It works with GY6-A engine cases that have a 54mm cylinder stud spacing. Confirm your engine's specs before ordering. It does not fit GY6 B-Block or 161QMK engines.
Technical Details
- Material: Aluminum
- Bore: 61mm
- Displacement: Approximately 171.3cc
- Outer Cylinder Skirt Diameter: 62.99mm
- Cylinder Stud Spacing: 54mm
- OEM Part Number: 603C02GY661
- Country of Origin: Taiwan
- Fits: GY6 150cc (157QMJ) engines with GY6-A case, 54mm stud spacing, 62.99mm skirt clearance
Compatible Vehicles
Fits:
- GY6 150cc (157QMJ) (GY6-A case, 54mm cylinder stud spacing, 62.99mm skirt clearance)
- Buddy 150 and Blur 150 (matching engine and case dimensions)
- TaoTao, Wolf, Ice Bear, Bintelli, Peace Sports, ZNEN, SSR, SYM and other QMI/QMJ-based GY6 scooters (select models)
- Hammerhead 150, Trailmaster 150, Yerf-Dog and Carter Talon go-karts and buggies (select models with matching QMI/QMJ engines)
- Matching 157QMJ, 1P57QMJ, 152QMI and BN157QMJ configurations
Selection tip: Verify the GY6-A case and 54mm cylinder stud spacing before purchase, and make sure the 62.99mm skirt will clear your case opening.
Placement: Refer to part #1 on the cylinder diagram for the GY6 150cc (157QMJ).
Alternate option: If you want the 63mm 180cc version for GY6 125cc and 150cc, see 63mm 180cc Big Bore Kit for GY6 125cc & 150cc.
Browse further: GY6 Scooter Parts · Chinese Scooter Parts · Scooter Big Bore & Cylinder Kits · Scooter Parts
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