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 Yamaha YZ250F 2019-2025 8957DA
WOSSNER
$184.00The stock piston in your YZ250F won't cut it if you're pushing hard on the track or trail. Wossner pistons are engineered for high-load durability and reduced friction, giving you reliable power delivery lap after lap. This complete kit gives you...09106138- SKU:
- 09106138
- Availability:
- Ships Same Business Day
- Weight:
- 0.40 LBS
- BORE SIZE METRIC:
- 77.00 MM
- COMPRESSION RATIO IMPERIAL:
- 14.0:1
- MODEL:
- PREMIUM SERIES
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- BORE - OVERSIZE:
- STANDARD
- PRODUCT NAME:
- PISTON KIT
- BORE - OVERSIZE METRIC:
- STANDARD
- ENGINE TYPE:
- 4-STROKE
- PISTON MATERIAL:
- ALUMINUM ALLOY
- PISTON MATERIAL:
- FORGED
- PISTON SIZE METRIC:
- 76.96 MM
$184.00 -
Wossner Piston Kit Yamaha YZ250F 2019-2025 8957DB
WOSSNER
$184.00The Wossner Piston Kit delivers the durability and precision needed to keep your YZ250F running strong through aggressive riding and repeated heat cycles. Built with German engineering and advanced metallurgy, this complete kit eliminates guesswork...09106139- SKU:
- 09106139
- Availability:
- Ships Same Business Day
- Weight:
- 0.51 LBS
- BORE - OVERSIZE METRIC:
- +0.01 MM
- BORE SIZE METRIC:
- 77.01 MM
- ENGINE TYPE:
- 4-STROKE
- PRODUCT NAME:
- PISTON KIT
- COMPRESSION RATIO IMPERIAL:
- 14.0:1
- MODEL:
- PREMIUM SERIES
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- BORE - OVERSIZE:
- +0,01 MM
- PISTON MATERIAL:
- ALUMINUM ALLOY
- PISTON MATERIAL:
- FORGED
- PISTON SIZE METRIC:
- 76.97 MM
$184.00 -
Wossner Piston Kit Yamaha YZ450F 2020-2022 8965DA
WOSSNER
$224.00If you're running hard on the track or pushing your YZ450F to its limits in competition, piston durability and throttle response are non-negotiable. The Wossner Piston Kit delivers the precision engineering and material science that separates competitive...09106142- SKU:
- 09106142
- Availability:
- Ships Same Business Day
- Weight:
- 0.71 LBS
- BORE - OVERSIZE:
- STANDARD
- MODEL:
- PREMIUM SERIES
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- BORE - OVERSIZE METRIC:
- STANDARD
- BORE SIZE METRIC:
- 97.00 MM
- COMPRESSION RATIO IMPERIAL:
- 13.2:1
- ENGINE TYPE:
- 4-STROKE
- PISTON MATERIAL:
- ALUMINUM ALLOY
- PISTON MATERIAL:
- FORGED
- PISTON SIZE METRIC:
- 96.96 MM
- PRODUCT NAME:
- PISTON KIT
$224.00Qty in Cart: 0Quantity:Price:$224.00Subtotal: -
Wossner Piston Kit Yamaha YZ450F 2003-2004 8562DA
WOSSNER
$194.00If you're running a YZ450F hard—whether on the track or in practice—piston failure isn't an option. The Wossner 8562DA gives you the durability and reliability needed to push your bike to its limits without compromise. Built with German engineering and...09106148- SKU:
- 09106148
- Availability:
- Ships Same Business Day
- Weight:
- 0.71 LBS
- PISTON MATERIAL:
- FORGED
- PISTON SIZE METRIC:
- 94.96 MM
- BORE SIZE METRIC:
- 95.00 MM
- MODEL:
- STANDARD SERIES
- RIDING STYLE:
- OFF-ROAD
- BORE - OVERSIZE:
- STANDARD
- BORE - OVERSIZE METRIC:
- STANDARD
- COMPRESSION RATIO IMPERIAL:
- 12.5:1
- ENGINE TYPE:
- 4-STROKE
- PISTON MATERIAL:
- ALUMINUM ALLOY
- PRODUCT NAME:
- PISTON KIT
- UNITS:
- KIT
$194.00Qty in Cart: 0Quantity:Price:$194.00Subtotal: -
Wossner Piston Kit Suzuki RM-Z450 2013-2025 12.5:1 CR 8886DB
WOSSNER
$204.00When you're pushing your RM-Z450 to the limit, factory pistons become your weakest link. The Wossner 12.5:1 Compression Ratio Piston Kit delivers the durability and precision engineering needed to handle aggressive riding and high-RPM demands, while the...09106152- SKU:
- 09106152
- Availability:
- Ships Same Business Day
- Weight:
- 0.91 LBS
- BORE - OVERSIZE:
- +0,01 MM
- BORE SIZE METRIC:
- 95.51 MM
- COMPRESSION RATIO IMPERIAL:
- 12.0:1
- PRODUCT NAME:
- PISTON KIT
- BORE - OVERSIZE METRIC:
- +0.01 MM
- ENGINE TYPE:
- 4-STROKE
- PISTON MATERIAL:
- ALUMINUM ALLOY
- PISTON MATERIAL:
- FORGED
- PISTON SIZE METRIC:
- 95.47 MM
- MODEL:
- STANDARD SERIES
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
$204.00 -
Wossner Piston Kit Honda CRF450R 2009-2012 13.4:1 8768DA
WOSSNER
$214.00A worn or stock piston limits your CRF450R's ability to maintain consistent power under load, leading to increased blow-by and reduced efficiency. The Wössner 8768DA replaces those limitations with a precision-engineered forged piston that delivers...09106153- SKU:
- 09106153
- Availability:
- Ships Same Business Day
- Weight:
- 0.86 LBS
- BORE SIZE METRIC:
- 96.00 MM
- PRODUCT NAME:
- PISTON KIT
- BORE - OVERSIZE METRIC:
- STANDARD
- COMPRESSION RATIO IMPERIAL:
- 13.4:1
- ENGINE TYPE:
- 4-STROKE
- MODEL:
- PRO SERIES
- PISTON MATERIAL:
- ALUMINUM ALLOY
- PISTON MATERIAL:
- FORGED
- PISTON SIZE METRIC:
- 95.96 MM
- BORE - OVERSIZE:
- STANDARD
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
$214.00Qty in Cart: 0Quantity:Price:$214.00Subtotal: -
Wossner Piston Kit Honda CRF 450 R 2013-2014 8880DA
WOSSNER
$204.00The stock piston in your Honda CRF 450 R can become a limitation when you're pushing harder on the track or trail. Wossner's purpose-built piston kit delivers the strength and reliability needed for sustained high-performance riding, with engineering...09106154- SKU:
- 09106154
- Availability:
- Ships Same Business Day
- Weight:
- 0.71 LBS
- PISTON MATERIAL:
- ALUMINUM ALLOY
- PISTON MATERIAL:
- FORGED
- PISTON SIZE METRIC:
- 95.96 MM
- BORE - OVERSIZE:
- STANDARD
- BORE - OVERSIZE METRIC:
- STANDARD
- BORE SIZE METRIC:
- 96.00 MM
- COMPRESSION RATIO IMPERIAL:
- 12.5:1
- ENGINE TYPE:
- 4-STROKE
- PRODUCT NAME:
- PISTON KIT
- MODEL:
- STANDARD SERIES
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
$204.00Qty in Cart: 0Quantity:Price:$204.00Subtotal: -
Wossner Piston Kit Honda CRF450R 2017-2025 95.95mm 13.5:1 8936DA
WOSSNER
$204.00The Wossner Piston Kit is engineered to restore or exceed your CRF450R's power output while delivering the durability required for sustained high-RPM operation. A complete piston replacement addresses wear that reduces compression, throttle response, and...09106157- SKU:
- 09106157
- Availability:
- Ships Same Business Day
- Weight:
- 0.85 LBS
- BORE - OVERSIZE:
- STANDARD
- BORE SIZE METRIC:
- 96.00 MM
- PRODUCT NAME:
- PISTON KIT
- COMPRESSION RATIO IMPERIAL:
- 13.5:1
- MODEL:
- PREMIUM SERIES
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- BORE - OVERSIZE METRIC:
- STANDARD
- ENGINE TYPE:
- 4-STROKE
- PISTON MATERIAL:
- ALUMINUM ALLOY
- PISTON MATERIAL:
- FORGED
- PISTON SIZE METRIC:
- 95.95 MM
$204.00 -
PROX Piston Kit 01.1113.B
PROX
$99.95A piston kit is critical to engine reliability and performance—worn or damaged pistons compromise compression, increase blow-by, and accelerate engine degradation. The PROX Piston Kit 01.1113.B delivers OEM-equivalent durability with precision...09100020- SKU:
- 09100020
- Availability:
- Ships Same Business Day
- Weight:
- 0.25 LBS
- PRODUCT NAME:
- PISTON KIT
- RIDING STYLE:
- OFF-ROAD
- BORE SIZE METRIC:
- 47.45 MM
- ENGINE TYPE:
- 2-STROKE
- PISTON SIZE METRIC:
- STANDARD SIZE B
- PISTON DIAMETER METRIC:
- 47.45 MM
- PISTON MATERIAL:
- ALUMINUM ALLOY
- UNITS:
- EACH
$99.95 -
PROX Piston Kit 01.1113.C
PROX
$99.95Whether you're rebuilding a tired engine or replacing worn pistons, the PROX Piston Kit 01.1113.C delivers the precision and reliability that professional rebuilds demand. Engineered as a direct OEM replacement with Japanese manufacturing standards, this...09100021- SKU:
- 09100021
- Availability:
- Ships Same Business Day
- Weight:
- 0.25 LBS
- PISTON DIAMETER METRIC:
- 47.46 MM
- PISTON SIZE METRIC:
- STANDARD SIZE C
- RIDING STYLE:
- OFF-ROAD
- BORE SIZE METRIC:
- 47.46 MM
- ENGINE TYPE:
- 2-STROKE
- PISTON MATERIAL:
- ALUMINUM ALLOY
- UNITS:
- EACH
- PRODUCT NAME:
- PISTON KIT
$99.95 -
PROX Piston Kit 01.4022.A
PROX
$88.95Worn or damaged pistons compromise combustion efficiency, reduce power output, and risk catastrophic engine failure. The PROX Piston Kit 01.4022.A delivers OEM-equivalent performance with precision engineering, ensuring reliable ring sealing, proper bore...09100022- SKU:
- 09100022
- Availability:
- Ships Same Business Day
- Weight:
- 0.25 LBS
- BORE SIZE METRIC:
- 44.45 MM
- PISTON DIAMETER METRIC:
- 42.96 MM
- PISTON MATERIAL:
- ALUMINUM ALLOY
- PRODUCT NAME:
- PISTON KIT
- UNITS:
- EACH
- PISTON SIZE METRIC:
- STANDARD SIZE A
- RIDING STYLE:
- OFF-ROAD
$88.95 -
PROX Piston Kit 01.4022.B
PROX
$88.95When your engine demands reliability under extreme conditions, OEM-spec pistons are non-negotiable. The PROX Piston Kit 01.4022.B delivers factory-quality performance with the precision tolerances required for high-RPM stability and consistent...09100023- SKU:
- 09100023
- Availability:
- Ships Same Business Day
- Weight:
- 0.25 LBS
- BORE SIZE METRIC:
- 44.46 MM
- PISTON MATERIAL:
- ALUMINUM ALLOY
- PRODUCT NAME:
- PISTON KIT
- UNITS:
- EACH
- PISTON DIAMETER METRIC:
- 44.46 MM
- PISTON SIZE METRIC:
- STANDARD SIZE B
- RIDING STYLE:
- OFF-ROAD
$88.95 -
PROX Piston Kit 01.4223.B
PROX
$105.95A piston kit is fundamental to engine longevity and performance—worn or damaged pistons compromise compression, increase blow-by, and accelerate engine wear. The PROX Piston Kit 01.4223.B delivers OEM-equivalent quality without the OEM price tag, using...09100025- SKU:
- 09100025
- Availability:
- Ships Same Business Day
- Weight:
- 0.25 LBS
- PISTON MATERIAL:
- ALUMINUM ALLOY
- PISTON DIAMETER METRIC:
- 53.96 MM
- RIDING STYLE:
- OFF-ROAD
- ENGINE TYPE:
- 2-STROKE
- PISTON SIZE METRIC:
- STANDARD SIZE B
- UNITS:
- EACH
- BORE SIZE METRIC:
- 53.96 MM
- PRODUCT NAME:
- PISTON KIT
$105.95Qty in Cart: 0Quantity:Price:$105.95Subtotal: -
PROX Piston Kit 01.4223.C
PROX
$101.95Worn or damaged pistons directly compromise engine reliability, power delivery, and fuel efficiency—making a quality replacement essential for any serious rebuild or refresh. The PROX Piston Kit 01.4223.C delivers OEM-specification performance with...09100026- SKU:
- 09100026
- Availability:
- Ships Same Business Day
- Weight:
- 0.25 LBS
- BORE SIZE METRIC:
- 53.97 MM
- PISTON SIZE METRIC:
- STANDARD SIZE C
- ENGINE TYPE:
- 2-STROKE
- PISTON MATERIAL:
- ALUMINUM ALLOY
- UNITS:
- EACH
- PISTON DIAMETER METRIC:
- 53.97 MM
- RIDING STYLE:
- OFF-ROAD
- PRODUCT NAME:
- PISTON KIT
$101.95Qty in Cart: 0Quantity:Price:$101.95Subtotal: -
PROX Piston Kit 01.2406.A
PROX
$179.95A piston kit is critical to engine reliability and performance—worn or damaged pistons compromise compression, fuel efficiency, and power delivery. The PROX Piston Kit 01.2406.A delivers OEM-equivalent quality with precision manufacturing, ensuring your...09100027- SKU:
- 09100027
- Availability:
- Ships Same Business Day
- Weight:
- 0.25 LBS
- PISTON DIAMETER METRIC:
- 76.95 MM
- BORE SIZE METRIC:
- 76.95 MM
- ENGINE TYPE:
- 4-STROKE
- PISTON MATERIAL:
- ALUMINUM ALLOY
- PRODUCT NAME:
- PISTON KIT
- UNITS:
- EACH
- PISTON SIZE METRIC:
- STANDARD SIZE A
- RIDING STYLE:
- OFF-ROAD
$179.95Qty in Cart: 0Quantity:Price:$179.95Subtotal: -
PROX Piston Kit 01.2406.B
PROX
$188.95A worn or damaged piston compromises engine compression, efficiency, and reliability—especially under boost or sustained high RPM. The PROX Piston Kit 01.2406.B delivers OEM-equivalent performance with precision manufacturing that ensures proper ring...09100028- SKU:
- 09100028
- Availability:
- Ships Same Business Day
- Weight:
- 0.25 LBS
- BORE SIZE METRIC:
- 76.96 MM
- ENGINE TYPE:
- 4-STROKE
- PISTON DIAMETER METRIC:
- 76.96 MM
- PISTON MATERIAL:
- ALUMINUM ALLOY
- PRODUCT NAME:
- PISTON KIT
- UNITS:
- EACH
- PISTON SIZE METRIC:
- STANDARD SIZE B
- RIDING STYLE:
- OFF-ROAD
$188.95 -
PROX Piston Kit 01.2427.A
PROX
$205.95A worn or damaged piston kit severely limits engine performance and can lead to catastrophic failure if not addressed promptly. The PROX Piston Kit 01.2427.A restores your engine to OEM specifications with precision-engineered components manufactured to...09100031- SKU:
- 09100031
- Availability:
- Ships Same Business Day
- Weight:
- 0.25 LBS
- BORE SIZE METRIC:
- 94.95 MM
- PISTON SIZE METRIC:
- STANDARD SIZE A
- RIDING STYLE:
- OFF-ROAD
- ENGINE TYPE:
- 4-STROKE
- PISTON DIAMETER METRIC:
- 94.95 MM
- PISTON MATERIAL:
- ALUMINUM ALLOY
- PRODUCT NAME:
- PISTON KIT
- UNITS:
- EACH
$205.95 -
PROX Piston Kit - KDX200 '86-'06 01.4285.D
PROX
$132.95A worn or damaged piston directly kills engine performance and reliability. The PROX Piston Kit restores your KDX200 to OEM specifications with Japanese-manufactured precision, ensuring consistent compression, reduced blow-by, and extended engine life...09101453- SKU:
- 09101453
- Availability:
- Ships Same Business Day
- Weight:
- 0.50 LBS
- PISTON DIAMETER METRIC:
- 65.97 MM
- PRODUCT NAME:
- PISTON KIT
- PISTON MATERIAL:
- ALUMINUM
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- ENGINE TYPE:
- 2-STROKE
- SKIRT COATING:
- MOLY COATED
$132.95 -
PROX Piston Kit 01.4409.A
PROX
$189.95If your engine is showing signs of wear—loss of compression, increased blow-by, or declining power output—a quality piston kit is essential to restore performance and reliability. The PROX Piston Kit 01.4409.A delivers OEM-level engineering with...09101465- SKU:
- 09101465
- Availability:
- Ships Same Business Day
- Weight:
- 0.82 LBS
- RIDING STYLE:
- OFF-ROAD
- PISTON MATERIAL:
- ALUMINUM ALLOY
- PRODUCT NAME:
- PISTON KIT
- UNITS:
- EACH
- BORE SIZE METRIC:
- 95.97 MM
- PISTON SIZE METRIC:
- STANDARD SIZE A
- PISTON DIAMETER METRIC:
- 95.97 MM
$189.95Qty in Cart: 0Quantity:Price:$189.95Subtotal: -
PROX Piston Kit 01.4409.B
PROX
$210.95Pistons are the heart of any engine, and worn or damaged units directly compromise compression, power delivery, and reliability. The PROX Piston Kit 01.4409.B delivers OEM-equivalent performance with precision engineering, making it the ideal choice for...09101466- SKU:
- 09101466
- Availability:
- Ships Same Business Day
- Weight:
- 0.85 LBS
- PISTON MATERIAL:
- ALUMINUM ALLOY
- PISTON SIZE METRIC:
- STANDARD SIZE B
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- EACH
- BORE SIZE METRIC:
- 95.98 MM
- PRODUCT NAME:
- PISTON KIT
- PISTON DIAMETER METRIC:
- 95.98 MM
$210.95
