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!
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- Qty in Cart
- Quantity
- Price
- Subtotal
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On Sale
Wossner Piston Kit 52.45mm Kawasaki KX112 2022-2023 8322DA
WOSSNER
MSRP: $112.00Now: $106.40Was: $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...09106847- SKU:
- 09106847
- Availability:
- Ships Same Business Day
- Weight:
- 0.35 LBS
MSRP: $112.00Now: $106.40Was: $112.00 -
On Sale
Wossner Piston Kit 53.95mm Yamaha YZ125 2022-2025 8321DA
WOSSNER
MSRP: $142.00Now: $134.90Was: $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...09106855- SKU:
- 09106855
- Availability:
- Ships Same Business Day
- Weight:
- 0.45 LBS
MSRP: $142.00Now: $134.90Was: $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...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
$346.99If 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...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
$346.99 -
JE PISTONS Piston Kit - 14.5:1 - Kawasaki 391920
JE PISTONS
$316.99If 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...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
$316.99 -
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...09106482- SKU:
- 09106482
- Availability:
- Ships Same Business Day
- Weight:
- 1.15 LBS
$386.95 -
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...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...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...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...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...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...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
$89.20Qty in Cart: 0Quantity:Price:$89.20Subtotal: -
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...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...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
$158.95Qty in Cart: 0Quantity:Price:$158.95Subtotal: -
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,...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...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
$183.95When 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...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
$183.95Qty in Cart: 0Quantity:Price:$183.95Subtotal: -
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...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...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...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:
