Cylinder Works 21007-K01 Big Bore Cylinder Kit – 52.5 mm – Yamaha YZ85 (2002-2018)
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Cylinder Works 21007-K01 Big Bore Cylinder Kit – 52.50 mm – Yamaha
Boost your Yamaha's performance with the Cylinder Works 21007-K01 Big Bore Cylinder Kit. This kit includes a direct bolt-on cylinder, Vertex piston, and top-end gaskets for enhanced power and reliability. We price-match reputable online stores—contact us to ensure you get the best deal! Note: Requires cylinder head modification.
✅ What’s Included
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Big Bore Cylinder (52.50 mm)
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Vertex Piston Kit (piston, rings, pin, clips)
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Top-End Gasket Kit
🔑 Key Features
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Big bore design increases displacement to 103.5 cc (+5.00 mm overbore)
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Nickel-silicon carbide-plated cylinder for durability and long life
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Includes matching Vertex pistons for longevity and reduced engine noise
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Virtually identical appearance to OEM cylinders
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Made in the U.S.A.
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Compression ratio: 8.2:1
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Warning: Cancer and Reproductive Harm - www.P65Warnings.ca.gov
📦 Fitment (Highlights)
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Yamaha:
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2002-2018 YZ85
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Notes: Always verify fitment by year, make, model, and engine specifications before ordering. Replaces OEM part numbers: 5PA113110000, 5PA113110100, 5PA113111000. Requires cylinder head modification.
💲 Price & SKU
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Retail Price: $885.95
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SKU: 0931-0346 / 21007-K01
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Note: We price-match reputable online stores—contact us for the best price!
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Weight: 3.6 lbs
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Dimensions: 6.42" (H) × 10.94" (L) × 8.57" (W)
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Availability: In stock. Ships next business day
🛡️ Warranty
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Contact Cylinder Works for warranty details (proof of purchase required)
📦 Shipping Information
In-stock items ship next business day. ModQuad parts dispatch Monday through Thursday.
Made-to-order and custom powder coat items show their lead time at the top of this page, right next to the truck icon. These are built fresh for you, so timing varies by brand and current backlog.
Need something by a specific date? Call us at 541-668-7503 before ordering and we will check stock and ETA on that exact part. We can often point you to an in-stock alternative from another distributor.
Questions? Contact us, we respond within 24 hours.