WH 125cc 150cc Rocket Arm

Brand: Mortch Motor
Product Code: MIWH125-3017

Product Viewed: 167

Availability: In Stock

Weight: 0.09kg

Packing Size: 6.00 x 6.00 x 3.00cm

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WH 125cc / 150cc Rocker Arm Assembly

🏍️ Rocker Arm Assembly · Valve Rocker · Performance Upgrade · Engine Valve Train

For QJ153QMI Engine · Compatible with Keeway ARN 125, F-act 125, Matrix 125, RY8 125, RX9 LEONE and GY6 Platform Models

📋 Product Overview

This is the WH High-Quality Rocker Arm Assembly — one of the most cost-effective ways to achieve real performance tuning. Through close collaboration with various 4-stroke scooter manufacturers, we have successfully increased engine performance and running smoothness. The result does not affect everyday drivability while still offering smooth running and exceptional durability.

A rocker arm is a lever that sits on top of the valve stem and opens and closes the intake and exhaust valves as the camshaft rotates. This rocker arm assembly is specifically designed for QJ153QMI engines and fits Keeway and other GY6-based 125cc and 150cc scooter models equipped with 153QMI or 152QMI engines. It is located inside the cylinder head cover.

✨ Core Functions: Transmit camshaft power · Precisely control valve timing · Optimize intake/exhaust efficiency · Enhance engine performance · Improve running smoothness

⚙️ How It Works & Performance Benefits

🔩 How It Works

The rocker arm acts as a transmission component between the camshaft and valves. As the camshaft rotates, it pushes one end of the rocker arm, causing it to pivot on its shaft. The opposite end presses down on the valve stem, overcoming valve spring resistance to open the valve. As the camshaft continues rotating, the valve spring returns, closing the valve. This cycle repeats to achieve precise intake and exhaust valve timing.

⚡ Performance Benefits

• Optimized valve lift profile for improved intake/exhaust efficiency
• Enhanced mid-range torque for smoother acceleration
• Improved fuel economy with reduced consumption
• Smoother operation with reduced engine noise
• Maintains everyday drivability without sacrificing durability

🏆 Most Cost-Effective Performance Upgrade: The rocker arm assembly is one of the most economical ways to enhance GY6 engine performance. Without major engine disassembly, simply replacing the rocker arms delivers noticeable power gains and improved running quality while maintaining OEM reliability and everyday riding comfort.

📐 Specifications

Displacement

125cc / 150cc

Engine Model

QJ153QMI / 152QMI (GY6)

Mounting Location

Inside Cylinder Head Cover

Material

High-Strength Alloy Steel

Kit Includes

Rocker Arm Assembly (Intake & Exhaust)

Engine Type

4-Stroke Scooter

🔧 Compatible Engines & Vehicles

Compatible Engine Models: QJ153QMI / 152QMI (GY6 Series)

QJ153QMI

152QMI (GY6)

Compatible Vehicles:

Keeway ARN 125
Keeway F-act 125
Keeway Matrix 125
Keeway RY8 125
Keeway RX9 LEONE
Other 125cc and 150cc scooter models equipped with QJ153QMI / 152QMI (GY6) engines

Engine Reference Information:

153QMI: Newer engine model, an improved version of the standard GY6 152QMI engine.
GY6 Platform: Widely used in 125cc/150cc scooters, one of the most common engine platforms worldwide.

Note: This rocker arm assembly is specifically designed for GY6 series engines. Please verify your engine model before installation.

✨ Product Features

Performance-Optimized Design: Precision-engineered rocker geometry and valve lift profile for improved intake and exhaust efficiency.
High-Strength Material: Manufactured from premium alloy steel with critical surfaces heat-treated for superior wear resistance and fatigue strength.
Precision Machining: Roller and contact surfaces are precision ground for smooth operation and reduced friction loss.
OEM Specification: Built to exact GY6 engine factory specifications for a perfect replacement of original components.
Preserves Everyday Drivability: Performance gains without sacrificing ride comfort, reliability, or durability.
Cost-Effective Upgrade: One of the most affordable performance tuning solutions — noticeable power improvement and smoother running with minimal investment.

🔧 Installation Guide

1. Ensure the engine is completely cooled and disconnect the negative battery terminal before starting.
2. Remove the cylinder head cover (valve cover) to expose the rocker arm assembly and valve train.
3. Rotate the crankshaft to top dead center (TDC) compression stroke and mark timing position to ensure correct camshaft orientation.
4. Remove the rocker arm shaft retaining bolts, then extract the rocker arm shaft and rocker arm assembly.
5. Clean the rocker arm shaft and mounting bore. Inspect the valve tappet and camshaft contact surfaces.
6. Install the new rocker arm assembly, apply engine oil to contact surfaces, insert the rocker arm shaft, and tighten retaining bolts to specified torque.
7. Adjust valve clearance to factory specifications (Intake: 0.10-0.12mm, Exhaust: 0.12-0.15mm).
8. Verify timing alignment, install a new valve cover gasket, reinstall the cylinder head cover, start the engine and check for proper operation.
Important Note: Proper valve clearance adjustment is critical — too tight will cause poor valve sealing, too loose will create noise and reduce performance. Professional installation is strongly recommended.

⚠️ Important Notice: This is the WH 125cc/150cc Rocker Arm Assembly, designed for QJ153QMI and GY6 series engines. Compatible with Keeway ARN 125, F-act 125, Matrix 125, RY8 125, RX9 LEONE, and similar platform scooters.
Spec Confirmation: Before purchasing, verify your engine model (153QMI/152QMI) to ensure compatibility.
Installation Caution: Rocker arm assembly installation involves the valve train. Proper valve clearance adjustment directly affects engine performance and reliability. Professional installation is strongly recommended. Always use a new valve cover gasket to prevent oil leaks. Product images are for reference only; actual product may vary.

🔧 Compatibility Notice

Please verify that this part fits your specific vehicle model and year. Many vehicles share similar names but use different components depending on year or market region.
We strongly recommend cross-checking with your vehicle's owner's manual or contacting us for confirmation before placing your order.

📄 Product Disclaimer

Product images, measurements, and descriptions are for reference only. Slight variations in color or appearance may occur due to manufacturing batches or photography lighting—functional specifications remain identical to the ordered part.
Professional installation is mandatory. Mortch Motor assumes no liability for damages, injuries, or losses resulting from improper installation, misuse, unauthorized modification, or abnormal operation.

💰 Import Duties & Taxes

All listed prices EXCLUDE shipping costs, import duties, taxes, and customs clearance fees. These charges (if applicable) are determined and collected by your local customs authority and are solely the buyer's responsibility.
In case of return due to unpaid duties/taxes or refusal to clear customs, the buyer shall bear the original shipping cost, return shipping fees, and any associated administrative charges deducted from the refund.

📌 Order Confirmation: By completing your purchase, you acknowledge that you have read, understood, and agreed to all terms above. For any questions, please contact our support team prior to ordering.