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Motorcycle Home Motorcycle Parts Engine Parts and Accessories Big Bore Kits

Motorcycle Big Bore Kits

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$40

Koso
Big Bore With 4 Valve Cylinder Head Kit

$854.96
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$15

Koso
Big Bore Kit

$310.46
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$30

Koso
4 Valve Cylinder Head Kit

$620.96
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Koso
High Flow Oil Pump

$43.16
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Most Recent Big Bore Kits Reviews

Athena Big Bore Kit

Athena Big Bore Kit

Roger21 - Tri cities Washington Awesome kit "Great kit really easy to install, I put it on my 07 CRF250R along wth a complete lower end rebuild, and stage 2 hotcam and it rips! Took some of the top end speed out so you’ll need a rear sprocket with less teeth good kit so far and seems high quality"
 See all reviews for this product Athena Big Bore Kit

Athena Big Bore Kit

Jerbo - Santa Rosa, Ca. Awesome "Fun to install and what an incredible change in performance!!!! The sound of the engine is a much deeper tone. Great for someone who doesn't necessarily know alot about engines. Follow the instructions and feel like you own your engine and its capability. It's very enpowering."
 See all reviews for this product