Universal Parts QMB139 Cylinder & Head Kit - 69mm Valves

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151-280 50

$89.00
$89.00
Shipping calculated at checkout.
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Description

50cc QMB139 4-stroke Cylinder and Head Kit With 69mm Valves. Choose from 39mm, 47mm or 50mm bore in the Drop Down Box.

47mm Bore Upgrades your Scooter to 72cc! 
50mm Bore Upgrades your Scooter to 81.3cc! 
 

Kit includes complete cylinder head, cylinder, piston, rings, piston pin, cir clips, head gasket, and base gasket.



*You may need to modify your engine case to accommodate the larger cylinder.

  • Cylinder Bore: Choose from 39mm, 47mm or 50mm
  • Cylinder Sleeve Outer Diameter: 45mm (39mm bore) / 52.8mm (47mm bore) / 52.6mm (50mm bore)
  • Wrist Pin Diameter: 13mm
  • Total Piston Height: 34.4mm
  • Compression Height (from center of wrist pin hole to top edge of piston): 17.25mm
  • Intake and Exhaust Valve Length: 69mm
  • Non-Emissions Head
QMB139 50cc/49cc

We Offer:

30-day returns for peace of mind

Expert support from scooter specialists

Flat-rate shipping to the lower 48 states

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Why Choose Classic Scooters USA

  • Reliable Shipping

    Orders are carefully packed and shipped with dependable delivery across the contiguous United States. Designed to get your scooter or parts to you safely and on time.

  • Easy Returns

    Our 30-day return policy makes it simple to shop with confidence and peace of mind. If something isn’t right, returns are straightforward and hassle-free.

  • Built Quality

    Every scooter, part, and accessory is selected for durability and long-term performance. Built to handle daily riding and real-world road conditions.

Orders

How do I place an order?

Simply browse our scooters, parts, or accessories, add your desired items to the cart, and proceed to checkout. Follow the prompts to enter your shipping and billing information, then confirm your order.

What payment methods do you accept?

We accept major credit and debit cards, including Visa, MasterCard, American Express, and Discover. We also support PayPal for secure online payments.

Can I pay in installments or financing?

Financing options may be available for certain scooters. Please check the product page or contact our customer support team to learn about current financing offers.

Products

What types of scooters do you offer?

We offer a variety of scooters, including classic-styled models, modern gas-powered scooters, and electric scooters. Options range from lightweight 50cc scooters to more powerful 150cc+ models for commuting or longer rides.

Are your scooters suitable for beginners?

Yes! Most of our scooters are easy to handle, lightweight, and beginner-friendly. They are designed for smooth rides and safe handling, making them perfect for first-time riders.

Shipping

How long will it take for my order to arrive?

Most orders are processed within 1–2 business days. Standard shipping to the 48 contiguous United States usually takes 3–7 business days, depending on your location and product availability.

How much does shipping cost?

We offer flat-rate shipping for orders shipped within the 48 contiguous states. Shipping costs are calculated at checkout and are designed to be simple and affordable.

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