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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- Price
- Subtotal
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On Sale
Wossner Piston Kit Yamaha YZ250F 2019-2025 8957DA
WOSSNER
MSRP: $184.00Now: $174.80Was: $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...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
MSRP: $184.00Now: $174.80Was: $184.00 -
On Sale
Wossner Piston Kit Yamaha YZ250F 2019-2025 8957DB
WOSSNER
MSRP: $184.00Now: $174.80Was: $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...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
MSRP: $184.00Now: $174.80Was: $184.00Qty in Cart: 0Quantity:Price:MSRP: $184.00Now: $174.80Was: $184.00Subtotal: -
On Sale
Wossner Piston Kit Yamaha YZ450F 2020-2022 8965DA
WOSSNER
MSRP: $224.00Now: $212.80Was: $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...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
MSRP: $224.00Now: $212.80Was: $224.00Qty in Cart: 0Quantity:Price:MSRP: $224.00Now: $212.80Was: $224.00Subtotal: -
On Sale
Wossner Piston Kit Yamaha YZ450F 2003-2004 8562DA
WOSSNER
MSRP: $194.00Now: $184.30Was: $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...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
MSRP: $194.00Now: $184.30Was: $194.00Qty in Cart: 0Quantity:Price:MSRP: $194.00Now: $184.30Was: $194.00Subtotal: -
On Sale
Wossner Piston Kit Suzuki RM-Z450 2013-2025 12.5:1 CR 8886DB
WOSSNER
MSRP: $204.00Now: $193.80Was: $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...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
MSRP: $204.00Now: $193.80Was: $204.00Qty in Cart: 0Quantity:Price:MSRP: $204.00Now: $193.80Was: $204.00Subtotal: -
On Sale
Wossner Piston Kit Honda CRF450R 2009-2012 13.4:1 8768DA
WOSSNER
MSRP: $214.00Now: $203.30Was: $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...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
MSRP: $214.00Now: $203.30Was: $214.00Qty in Cart: 0Quantity:Price:MSRP: $214.00Now: $203.30Was: $214.00Subtotal: -
On Sale
Wossner Piston Kit Honda CRF 450 R 2013-2014 8880DA
WOSSNER
MSRP: $204.00Now: $193.80Was: $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...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
MSRP: $204.00Now: $193.80Was: $204.00Qty in Cart: 0Quantity:Price:MSRP: $204.00Now: $193.80Was: $204.00Subtotal: -
On Sale
Wossner Piston Kit Honda CRF450R 2017-2025 95.95mm 13.5:1 8936DA
WOSSNER
MSRP: $204.00Now: $193.80Was: $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...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
MSRP: $204.00Now: $193.80Was: $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...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...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...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...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...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...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...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...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...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...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...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...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
