28mm INTAKE / 23mm EXHAUST • GY6 PERFORMANCE

Upgrade or rebuild your performance GY6 cylinder head with the NCY High-RPM Racing Valve Set.

Designed for compatible GY6 125cc, 150cc and big-bore performance engines, these oversized valves feature a 27.8mm intake and 22.9mm exhaust with 5mm valve stems.

They are also the correct replacement valve set for the NCY Big Valve High-Flow Cylinder Head – SKU 1100-1254.

Made in Taiwan by NCY.

WHAT'S INCLUDED

1 × NCY Intake Valve
1 × NCY Exhaust Valve

VALVE SPECIFICATIONS

INTAKE VALVE

• Valve Head Diameter: 27.8mm

• Overall Length: 65.75mm

• Stem Diameter: 5.0mm

EXHAUST VALVE

• Valve Head Diameter: 22.9mm

• Overall Length: 65.3mm

• Stem Diameter: 5.0mm

MPN: 665C13GY628LL
SKU: 1100-1257
Country of Origin: Taiwan

PERFORMANCE FEATURES

• Oversized 27.8mm intake / 22.9mm exhaust valve configuration

• Designed for compatible high-flow GY6 cylinder heads

• Precision-finished valve seating surfaces

• Helps maintain proper cylinder sealing and compression

• Designed for demanding performance and higher-RPM applications

• Increased airflow potential compared with smaller stock-valve configurations

• Excellent for compatible big-bore and high-flow cylinder-head builds

• Premium NCY performance component

• Made in Taiwan

PERFECT REPLACEMENT FOR NCY BIG VALVE HEAD

These are the replacement valves for the:

NCY BIG VALVE HIGH-FLOW CYLINDER HEAD

SKU: 1100-1254

That cylinder head uses the same:

27.8mm Intake Valve
22.9mm Exhaust Valve
5.0mm Valve Stems

Cylinder head is NOT included with this listing.

COMMON PERFORMANCE APPLICATIONS

Designed for compatible GY6 cylinder heads found on:

• GY6 125cc engines

• GY6 150cc engines

• 155cc performance builds

• 169cc / 171cc performance builds

• 58.5mm big-bore applications

• 61mm big-bore applications

• 62mm / 63mm builds when using a compatible cylinder head

• NCY high-flow performance cylinder heads

Common compatible engine families can include:

• 152QMI

• 157QMJ

• 1P57QMJ

• YN1P57QMJ

• Other compatible QMI / QMJ configurations using these exact valve dimensions

WILL NOT FIT QMK / K-BLOCK CYLINDER HEADS

These valves should NOT be purchased for:

• 161QMK

• 1P61QMK

• BN161QMK-A

• QMK cylinder heads

• K-Block / QMK cylinder heads

QMK/K-Block engines use a different cylinder-head/valve configuration.

DO NOT ORDER BY ENGINE DISPLACEMENT ALONE.

A scooter being labeled 150cc, 170cc or 171cc does not guarantee fitment.

VERIFY YOUR OLD VALVES BEFORE ORDERING

Please compare your existing valves with these measurements:

INTAKE

27.8mm Head × 65.75mm Length × 5.0mm Stem

EXHAUST

22.9mm Head × 65.3mm Length × 5.0mm Stem

Modified engines and aftermarket cylinder heads may use different valve sizes even when the engine code appears compatible.

GENUINE SCOOTER APPLICATIONS

These valves may be used with compatible performance cylinder-head configurations associated with applications such as:

• Genuine Buddy 125

• Genuine Buddy 150

• Genuine Buddy 170i

• Genuine Blur 150

IMPORTANT: Verify the existing cylinder head and valve dimensions before ordering. Model name alone should not be used to determine fitment.

IDEAL FOR PERFORMANCE BUILDS

A great choice when rebuilding or servicing a compatible performance GY6 cylinder head used with:

• Big-bore cylinder kits

• High-flow cylinder heads

• Performance camshafts

• Larger carburetors

• Performance intake systems

• Performance exhaust systems

• Higher-RPM engine combinations

When building a modified engine, always verify valve-to-piston clearance, valve-seat compatibility, valve guides, retainers, keepers and spring compatibility before operation.

✓ 27.8mm INTAKE

✓ 22.9mm EXHAUST

✓ 5mm VALVE STEMS

✓ GY6 QMI / QMJ COMPATIBLE HEADS

✓ NCY BIG VALVE HEAD SKU 1100-1254

✓ PERFORMANCE / BIG-BORE APPLICATIONS

✕ NOT FOR QMK HEADS

✕ NOT FOR 161QMK

✕ NOT FOR 1P61QMK

✕ NOT FOR K-BLOCK / QMK HEADS

NCY PERFORMANCE

28/23mm HIGH-RPM RACING VALVE SET

MADE IN TAIWAN

MPN: 665C13GY628LL | SKU: 1100-1257

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