RDLN GY6 Big Bore Kit 180cc - 63mm

Unlock maximum displacement from your power plant with the RDLN 180cc Big Bore Cylinder Kit . Engineered to push the standard 150cc GY6 platform to its absolute performance limit, this kit features an oversized 63mm ceramic-composite coated cylinder bore. Delivering a massive increase in low-end torque and mid-range hill-climbing power, it is the ultimate upgrade for competitive track builds, high-load utility ATVs, and off-road go-karts. CRITICAL INSTALLATION WARNING: Because the cylinder sleeve outer diameter measures 64.9mm, this kit may require machined widening of your engine case to accommodate the larger sleeve. Attempting to force-fit without case modification will damage the cylinder jacket. Use our specialized Engine Case Boring Tool (SKU: 202-37) to complete this modification. Product Features Maximum Displacement: Boosts standard 125cc/150cc short or long-case variants up to a true 180cc (based on stock 57.8mm stroke). Optimized Heat Dissipation: Advanced cast alloy construction with precision cooling fins limits thermal saturation during continuous wide-open throttle (WOT) loads. Complete Top-End Package: Includes the 63mm cylinder barrel, matched light-alloy piston, performance wrist pin, dual circlips, high-tension compression rings, head gasket, and base gasket. Technical Specifications Cylinder Bore Diameter: 63mm Sleeve Outer Diameter (Skirt): 64.9mm Cylinder Total Structural Height: 90.5mm Stud Spacing Fitment: Standard 54mm engine configurations Expanded Model Fitment & Vehicle Engine Guide This kit fits 4-stroke, 54mm stud-spaced GY6 engine cases (Engine Codes listed below) commonly utilized across a massive variety of street scooters, off-road buggies, and heavy-duty utility carts. Application Category Known Compatible Models & Platforms (Case Boring Required) Off-Road Go-Karts / Buggies Hammerhead 150cc Series (GTS150, GT150, Twister), Carter Talon 150, Trailmaster 150 XRX/XRS, American Sportworks, Manco Helix 150 UTVs & ATVs TaoTao Bull 150, Rhino 150, Polaris Phoenix 200 (GY6 clone builds), SunL 150cc Utility series Street & Sport Scooters Genuine Buddy 150, ZNEN 150cc, Wolf Brand 150, Ice Bear, Bintelli, Lance, Jonway, Roketa 125/150 variants Other 150cc Engine Codes 157QMJ, 161QMK, 152QMI, 1P61QMK, YN1P57QMJ, 1P52FMI, 154FMI, JJ157QMJ, 1P57QMJ, BN157QMJ, BN161QMK-A Tuning Mechanic's Recommendation: To support the massive air/fuel demands of a 180cc upgrade, you must up-jet your factory carburetor or upgrade to a high-flow 26mm–30mm performance carburetor setup. For the ultimate pairing, consider matching this kit with a high-performance A9 or A12 camshaft to extract optimal top-end valve lift cycle coefficients. California Prop 65 Warning Original Parts For Scooters SKU 164-310