Engines and Components› Pistons and Piston Rings

United Engine & Machine Co

1 SET KB125.040/1 SET 4125AM8.040

$565.00

SKU: U00B KB125KTM.040

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Special Order
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Non-Returnable Item
INSTALL DIFFICULTY
DIY PRO SHOP

Professional / shop required

Description

The Keith Black KB125KTM.040 piston kit is a flat-top, 7cc design with 2 valve reliefs, an oversized bore of 4.165 inches, a stroke of 3.750 inches, and a compression height of 1.433 inches. Made from a low expansion 390 hypereutectic alloy, these pistons are designed for enhanced durability and performance in high-stress engine applications.

Fitment

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Specifications

BrandUnited Engine & Machine Co
Part NumberU00B KB125KTM.040

Videos

Cast vs Hypereutectic vs Forged Pistons | Whats the Difference?

Cast vs Hypereutectic vs Forged Pistons | Whats the Difference?
#shorts Installing Press Fit Pistons on Connecting Rods

#shorts Installing Press Fit Pistons on Connecting Rods

Buy with Confidence

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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