Scooterworks

180cc Big Bore Kit 63mm Bore

$127.00

SKU: 1100-1438

In Stock
In Stock
Ships by Aug 31
Free Shipping over $200
$100 Minimum Order
30 Days Return

Description

The Scooterworks Big Bore Kit offers a significant displacement upgrade for GY6 150cc engines, increasing performance by expanding the engine to 180cc with a 63mm bore. Included components are a cylinder, piston, pin, circlips, rings, head gasket, and base gasket. Key specifications for this kit are a 63mm bore, a 90.5mm overall height, and a 64.9mm cylinder sleeve outer diameter. It is designed to work with a stock stroke of 57.8mm. Compatibility is broad, covering 157QMJ-based 125cc, 150cc, and 169cc engines with specific engine codes such as 157QMJ, 161QMK, 152QMI, 1P61QMK, YN1P57QMJ, 1P52FMI, 154FMI, JJ157QMJ, 1P57QMJ, BN157QMJ, and BN161QMK-A, as well as other QMJ, QMK, and QMI models. If the engine code includes "QM" or "FM", it is likely compatible. Please note that installation of this big bore kit may require modification of the engine case to accommodate the larger cylinder. An engine boring tool is available separately.

Product descriptions are provided by our supplier partners and may not always be perfectly accurate. Not sure this fits? or call (760) 282-4645 and we’ll verify before you order.

Fitment

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Specifications

BrandScooterworks
Part Number1100-1438
CategoryEngines and Components

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Returns & Fitment

Built for enthusiasts. Every order is backed by our 30 day return window on eligible items. Unused and uninstalled products may be returned with approved RMA and no restocking fees when received in new condition. Orders placed through the MOTORMIA app with a complete build qualify for our Fitment Guarantee — free return shipping if the part doesn’t fit your exact setup. The guarantee covers fit only; installation must follow manufacturer instructions, and we recommend a qualified shop for parts marked Difficulty 4–5.

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Shipping

Orders are processed in 1–3 business days. In stock parts ship promptly from our partner network. Special-order items either aren’t currently stocked or are built to your spec — expect 4–6 weeks. If a part goes on backorder while your order is in the queue, we’ll reach out and work through discounted alternatives together.

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