NCY Cylinder Head (2 valve, Big Valve, 61mm); Genuine, GY6
NCY Big Valve Cylinder Head (61mm): 171cc High-Flow for GY6
$153.78
10 in stock
*Note: Free shipping to U.S. mainland (excludes AK, HI, and territories)
Orders placed by 1pm EST on weekdays ship the same day.
Product Details
Description
NCY Big Valve Cylinder Head – 61mm – 171cc High-Flow for GY6
Replacement Part Details
Use this part when the original component is worn, damaged, missing, or no longer working correctly. Many scooter parts can look similar but use different sizes, plugs, brackets, thread patterns, or mounting styles, so careful comparison before purchase is recommended.
Compatibility / Fitment
Use the fitment details below to confirm this part matches your scooter before ordering.
- Engine Size: GY6
Fitment Guide: This compatibility information is based on manufacturer and supplier data. Listed models are common known applications and may not include every compatible scooter. If your scooter has multiple versions or production changes, confirm the correct match before ordering. Check photos, measurements, original part numbers, engine code, model, and related fitment information whenever possible.
Common Fitment Questions
Q: Is this for GY6 scooters?
A: This SKU is listed with GY6 engine-size fitment. Confirm exact model, year, and part style before ordering.
Additional information
| Weight | 4 lbs |
|---|---|
| Dimensions | 7.75 × 7 × 3 in |
| Condition | New |
|---|
Maximize your motor's torque and top-end breathing capacity with the premium NCY Big Valve High-Flow Cylinder Head. Engineered specifically to complement large-displacement performance upgrades, this 61mm cylinder head features optimized porting and oversized valves that allow your engine to move air in and out of the combustion chamber far more efficiently. The result is an immediate boost in throttle response, cleaner acceleration, and smoother operation across your entire power band.
Please note: This item is sold without any additional parts. It is the cylinder head body by itself.
Advanced Performance Features
- Oversized Valve Setup: Equipped with large 27.8mm intake and 22.9mm exhaust valves to drastically decrease intake restriction and optimize cylinder head breathing.
- High-Flow Porting Matrix: Cast and precision-finished in Taiwan with smooth internal runners that eliminate factory restrictions and fuel puddling.
- Thermal Management Layout: Constructed from a premium-grade aluminum alloy with wide cooling fins to quickly shed heat under extreme, high-bore engine loads.
Vehicle & Engine Fitment
This high-performance big valve head is tailored as a premium bolt-on upgrade for standard (B-Case) air-cooled GY6 4-stroke platforms. Built strictly for 61mm / 171cc cylinder kits (SKU 1100-1288).
OEM replacement valves are Sku: 1100-1257 NCY High-RPM Racing Valve Set - 28/23mm for GY6
| Vehicle Manufacturer / Class | Specific Eligible Model & Engine Lines |
|---|---|
| Genuine Scooter Co. | Buddy 125, Buddy 150, Buddy 170i, Hooligan 170i, Blur 150 |
| Go-Karts / Buggies | Hammerhead 150, Trailmaster 150 (All Variants), Yerf-Dog, Carter Talon |
| Chinese GY6 Brands | TaoTao, Wolf, Ice Bear, Bintelli, Peace Sports, ZNEN, SSR, and Kymco |
| Applicable Engine Codes | 157QMJ, 1P57QMJ, 152QMI, 161QMK, BN157QMJ, BN161QMK-A |
TUNING REQUIREMENT: Upgrading to a high-flow, big-valve setup demands significantly more fuel. To prevent a dangerous lean condition, you must upjet your carburetor (typically a #125 or #130 main jet depending on elevation).
Technical Specifications
- Intake Valve Diameter: 27.8 mm
- Exhaust Valve Diameter: 22.9 mm
- Exhaust Thread: Standard 8mm diameter
- Target Cylinder Bore: 61mm (Up to 171cc)
- Manufacturing Origin: Taiwan (ISO 9001 Certified)
- SKU: 1100-1254
Visit our NCY Performance Parts page to shop all performance upgrades available for your vehicle.
Mechanic's Installation Tip: Big bore and high-flow head upgrades naturally increase internal crankcase pressures. We highly recommend pairing this build with a Decompression Tube Assembly in place of your oil dipstick to vent excess pressure safely. Always double-check your valve clearance settings using a feeler gauge after torquing down the head bolts to prevent mechanical contact on your initial startup.
About NCY
NCY is the aftermarket performance parts leader for the most popular scooter brands, including Honda, Yamaha, Genuine, Vespa, SYM, Lance, KYMCO, and GY6/QMB powered scooters. Made in Taiwan with strict quality standards since 1997, NCY is ISO 9001 certified.
SKU: 1100-1254 | Vendor: NCY | Category: Cylinder Heads in Motor Vehicle Engine Parts
This product is not intended for use on public roads or land.
Not legal for use in California on pollution-controlled vehicles. Check local laws before installation.
