Dirt Bike Piston and Ring Kits
Dirt Bike Piston & Ring Kits for Yamaha YZ85, WR250 & YZ250 at JJ Motorsports
Rebuild your dirt bike's top end for maximum power and reliability with premium piston and ring kits from JJ Motorsports, forged from high-strength aluminum for superior heat resistance, lightweight performance, and precise fit in motocross, enduro, and trail riding. Our selection includes complete kits with pistons, high-performance rings, wrist pins, circlips, top-end bearings, and gaskets designed for enhanced combustion efficiency, reduced blow-by, and longer engine life under high-RPM abuse. Compatible with popular models like Yamaha YZ85 (2002-2018), WR250, and YZ250, these Wiseco-engineered components feature CNC-machined crowns for optimal cam shape, ArmorGlide skirt coatings for low friction, and 4032 alloy construction for durability in dusty, aggressive conditions. Whether you're refreshing a youth 85cc 2-stroke or upgrading a 250cc big bore, these kits ensure crisp throttle response, better sealing, and race-ready power without the need for custom boring—perfect for DIY rebuilds or pro-level maintenance.
Shop trusted brands like Wiseco for race-proven quality. Explore related categories such as dirt bike engine for cylinders and valves or dirt bike air and fuel for carburetors and jets.
Top Dirt Bike Piston & Ring Kits
- Wiseco YZ85 2002-2018 Piston Kit with Gaskets PK1202 – 47.50mm forged aluminum piston kit for Yamaha YZ85 2-stroke; includes rings, wrist pin, circlips, bearing, and gaskets for enhanced combustion and throttle response.
- Wiseco 68.00mm Piston Kit with Gaskets Yamaha WR/YZ 250 PK1563 – Complete big bore kit for Yamaha WR250/YZ250; features forged piston, rings, wrist pin, circlips, and top-end gaskets for superior power and sealing.
Browse our in-stock inventory below with same-day shipping and expert support. Free shipping on orders over $99! Questions? Contact us for fitment advice!
- Product
- Qty in Cart
- Quantity
- Price
- Subtotal
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Wossner Piston Kit 52.45mm Kawasaki KX112 2022-2023 8322DA
WOSSNER
$112.00Factory pistons wear out—especially under racing conditions or aggressive riding. The Wossner 52.45mm Piston Kit restores lost compression, reduces noise, and delivers the reliability you need for consistent performance lap after lap. This is a complete,...09106847- SKU:
- 09106847
- Availability:
- Ships Same Business Day
- Weight:
- 0.35 LBS
$112.00 -
Wossner Piston Kit 53.95mm Yamaha YZ125 2022-2025 8321DA
WOSSNER
$142.00If you're running a YZ125 at the edge of its limits, piston wear is inevitable—and a worn piston directly kills performance and reliability. This Wossner kit delivers OEM-quality construction with precision engineering that restores your engine's...09106855- SKU:
- 09106855
- Availability:
- Ships Same Business Day
- Weight:
- 0.45 LBS
$142.00 -
JE PISTONS Piston Kit - 12.5:1 - Kawasaki 379937
JE PISTONS
$329.99When you're pushing your Kawasaki to competition limits, stock pistons won't cut it. JE's 12.5:1 compression kit delivers the strength and reliability you need to extract maximum power without sacrificing durability. Built from 2618-T6 forged aluminum...09106678- SKU:
- 09106678
- Availability:
- Ships Same Business Day
- Weight:
- 1.10 LBS
- COMPRESSION RATIO IMPERIAL:
- 12.5:1
- RIDING STYLE:
- OFF-ROAD
- PISTON MATERIAL:
- FORGED 2618 ALUMINUM
- UNITS:
- KIT
- PRODUCT NAME:
- PISTON KIT
$329.99Qty in Cart: 0Quantity:Price:$329.99Subtotal: -
JE PISTONS Piston Kit - 13.5:1 - Kawasaki 379938
JE PISTONS
$329.99If you're running your Kawasaki engine at the edge of competition, your stock pistons won't survive—you need forged internals engineered for extreme duty. JE's 13.5:1 compression pistons deliver the strength and precision required for professional racing...09106679- SKU:
- 09106679
- Availability:
- Ships Same Business Day
- Weight:
- 1.07 LBS
- PRODUCT NAME:
- PISTON KIT
- UNITS:
- KIT
- RIDING STYLE:
- OFF-ROAD
- COMPRESSION RATIO IMPERIAL:
- 13.5:1
- PISTON MATERIAL:
- FORGED 2618 ALUMINUM
$329.99 -
JE PISTONS Piston Kit - 14.5:1 - Kawasaki 391920
JE PISTONS
$301.06If you're running a high-compression build or pushing your Kawasaki engine into professional competition territory, you need pistons engineered for the abuse. JE's 14.5:1 compression kit delivers the strength and precision required to survive extreme...09106680- SKU:
- 09106680
- Availability:
- Ships Same Business Day
- Weight:
- 0.78 LBS
- PISTON MATERIAL:
- FORGED 2618 ALUMINUM
- RIDING STYLE:
- OFF-ROAD
- COMPRESSION RATIO IMPERIAL:
- 14.5:1
- PRODUCT NAME:
- PISTON KIT
- UNITS:
- KIT
$301.06 -
MOOSE RACING Piston Kit MX2045
MOOSE RACING
$386.95If you're pushing your engine to the limit, your stock pistons aren't built for it. The MOOSE RACING Piston Kit MX2045 combines race-proven forging technology with advanced stress-relief engineering to deliver the durability, power, and reliability...09106482- SKU:
- 09106482
- Availability:
- Ships Same Business Day
- Weight:
- 1.15 LBS
$386.95Qty in Cart: 0Quantity:Price:$386.95Subtotal: -
MOOSE RACING Piston Kit MP4028
MOOSE RACING
$326.95High-performance racing demands pistons engineered for extreme conditions—and the MOOSE RACING Piston Kit MP4028 delivers the strength, durability, and power output required to dominate on the track. Built with X-style and fully-boxed race forgings,...09106485- SKU:
- 09106485
- Availability:
- Ships Same Business Day
- Weight:
- 1.41 LBS
$326.95 -
MOOSE RACING Piston Kit MPX1110
MOOSE RACING
$386.95High-performance racing demands pistons engineered to handle extreme cylinder pressures, elevated temperatures, and sustained RPM loads without compromise. The MOOSE RACING Piston Kit MPX1110 delivers the durability and power output serious racers need...09106520- SKU:
- 09106520
- Availability:
- Ships Same Business Day
- Weight:
- 1.11 LBS
$386.95 -
MOOSE RACING Piston Kit MP2017
MOOSE RACING
$326.95If you're serious about top-end performance and reliability under extreme conditions, the MOOSE RACING Piston Kit MP2017 delivers the precision engineering that separates winning builds from the rest. Built with X-style and fully boxed-style forgings,...09106474- SKU:
- 09106474
- Availability:
- Ships Same Business Day
- Weight:
- 1.25 LBS
$326.95 -
MOOSE RACING Piston Kit MP4010A
MOOSE RACING
$326.95Whether you're chasing lap times or building a reliable high-RPM engine, piston durability and friction loss directly impact both performance and longevity. The MOOSE RACING Piston Kit MP4010A is engineered to withstand extreme combustion pressures while...09106475- SKU:
- 09106475
- Availability:
- Ships Same Business Day
- Weight:
- 1.16 LBS
$326.95 -
MOOSE RACING Piston Kit MPX2010
MOOSE RACING
$386.95If you're serious about extracting maximum power and reliability from your engine, your piston assembly needs to match the demands of high-RPM racing. The MOOSE RACING Piston Kit MPX2010 is engineered to handle extreme conditions with internal bracing...09106486- SKU:
- 09106486
- Availability:
- Ships Same Business Day
- Weight:
- 1.16 LBS
$386.95 -
MOOSE RACING Piston Kit - 44.97 mm MSE23430CD
MOOSE RACING
$89.20A quality piston kit is fundamental to engine reliability and longevity, especially in high-demand racing and performance applications. The MOOSE RACING Piston Kit delivers proven durability through gravity-cast construction and nitride-coated components...09102717- SKU:
- 09102717
- Availability:
- Ships Same Business Day
- Weight:
- 0.25 LBS
- PRODUCT NAME:
- PISTON KIT
- UNITS:
- KIT
- PISTON MATERIAL:
- ALUMINUM ALLOY
- ENGINE TYPE:
- 2-STROKE
- PISTON DIAMETER METRIC:
- 44.97 MM
- RIDING STYLE:
- OFF-ROAD
$89.20 -
MOOSE RACING Piston Kit - 71.94 mm MSE24244B
MOOSE RACING
$235.95If you're rebuilding an engine or replacing worn pistons, you need components engineered to withstand extreme combustion pressures while minimizing thermal distortion and wear. The MOOSE RACING Piston Kit MSE24244B delivers exactly that—a gravity-cast...09105953- SKU:
- 09105953
- Availability:
- Ships Same Business Day
- Weight:
- 0.75 LBS
- PRODUCT NAME:
- PISTON KIT
- PISTON MATERIAL:
- ALUMINUM ALLOY
- ENGINE TYPE:
- 2-STROKE
- PISTON DIAMETER METRIC:
- 71.94 MM
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
$235.95 -
MOOSE RACING Piston Kit - 48.45 mm MSE23637B
MOOSE RACING
$158.95When your engine's piston assembly shows signs of wear or you're rebuilding for increased durability, a quality replacement kit is essential to maintain compression, reduce blow-by, and ensure consistent performance across the power band. The MOOSE...09105954- SKU:
- 09105954
- Availability:
- Ships Same Business Day
- Weight:
- 0.25 LBS
- PISTON DIAMETER METRIC:
- 48.45 MM
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- PRODUCT NAME:
- PISTON KIT
- PISTON MATERIAL:
- ALUMINUM ALLOY
$158.95 -
MOOSE RACING Piston Kit - 57.95 mm MSE24101B
MOOSE RACING
$206.95A piston kit that delivers measurable reliability gains where it counts most—inside your engine. The gravity-cast aluminum construction with 18% silicon content resists thermal distortion and wear, giving you extended service life without sacrificing...09105956- SKU:
- 09105956
- Availability:
- Ships Same Business Day
- Weight:
- 0.25 LBS
- PISTON DIAMETER METRIC:
- 57.95 MM
- PRODUCT NAME:
- PISTON KIT
- UNITS:
- KIT
- PISTON MATERIAL:
- ALUMINUM ALLOY
- RIDING STYLE:
- OFF-ROAD
$206.95 -
MOOSE RACING Piston Kit - 55.95 mm MSE23383A
MOOSE RACING
$131.95A piston kit is the heart of your engine's combustion chamber, and choosing the right one directly impacts reliability, longevity, and power delivery. The MOOSE RACING MSE23383A combines proven gravity-cast aluminum construction with advanced coatings...09102715- SKU:
- 09102715
- Availability:
- Ships Same Business Day
- Weight:
- 0.45 LBS
- UNITS:
- KIT
- RIDING STYLE:
- OFF-ROAD
- ENGINE TYPE:
- 2-STROKE
- PISTON DIAMETER METRIC:
- 55.95 MM
- PRODUCT NAME:
- PISTON KIT
- PISTON MATERIAL:
- ALUMINUM ALLOY
$131.95Qty in Cart: 0Quantity:Price:$131.95Subtotal: -
MOOSE RACING Piston Kit - 66.35 mm MSE22584B
MOOSE RACING
$169.95When your piston package fails mid-season, you need a direct replacement engineered to outlast the original—not a compromise. The MOOSE RACING Piston Kit MSE22584B combines gravity-cast aluminum with 18% silicon reinforcement to resist thermal distortion...09102684- SKU:
- 09102684
- Availability:
- Ships Same Business Day
- Weight:
- 0.70 LBS
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- ENGINE TYPE:
- 2-STROKE
- PISTON DIAMETER METRIC:
- 66.35 MM
- PRODUCT NAME:
- PISTON KIT
- PISTON MATERIAL:
- ALUMINUM ALLOY
$169.95Qty in Cart: 0Quantity:Price:$169.95Subtotal: -
MOOSE RACING Piston Kit - 53.96 mm MSE22652B
MOOSE RACING
$170.95A piston kit built to outlast the competition. The gravity-cast aluminum alloy with 18% silicon resists wear and thermal distortion better than standard pistons, meaning longer engine life and more reliable performance between rebuilds. Whether you're...09102688- SKU:
- 09102688
- Availability:
- Ships Same Business Day
- Weight:
- 0.39 LBS
- PRODUCT NAME:
- PISTON KIT
- PISTON DIAMETER METRIC:
- 53.96 MM
- PISTON MATERIAL:
- ALUMINUM ALLOY
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- ENGINE TYPE:
- 2-STROKE
$170.95 -
WSM Piston Kit - Kawasaki 900 - +.5 mm 010-840-05K
WSM
$80.40If you're building a high-displacement Kawasaki 900 engine or refreshing tired cylinders, this WSM piston kit delivers OEM-quality construction with measurable performance gains. The MOS2-coated skirts actively dissipate heat through the piston walls...01084005- SKU:
- 01084005
- Availability:
- Ships Same Business Day
- Weight:
- 1.00 LBS
- MODEL:
- ORIGINAL
- UNITS:
- KIT
- BORE - OVERSIZE METRIC:
- +0.50 MM
- RIDING STYLE:
- WATERCRAFT
- BORE - OVERSIZE:
- +0,50 MM
- BORE SIZE METRIC:
- 73.00 MM
- PISTON MATERIAL:
- ALUMINUM
- PRODUCT NAME:
- PISTON KIT
$80.40Qty in Cart: 0Quantity:Price:$80.40Subtotal: -
WSM Piston Kit - Kawasaki - Standard 010-810K
WSM
$82.17Your piston kit is the foundation of reliable power output and engine longevity. OEM-equivalent construction combined with advanced thermal management means you're getting professional-grade durability without compromising performance. Whether you're...010810- SKU:
- 010810
- Availability:
- Ships Same Business Day
- Weight:
- 0.81 LBS
- BORE - OVERSIZE:
- STANDARD
- BORE - OVERSIZE METRIC:
- STANDARD
- MODEL:
- ORIGINAL
- PRODUCT NAME:
- PISTON KIT
- UNITS:
- KIT
- RIDING STYLE:
- WATERCRAFT
- BORE SIZE METRIC:
- 76.00 MM
- PISTON MATERIAL:
- ALUMINUM
$82.17Qty in Cart: 0Quantity:Price:$82.17Subtotal:
