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
-
JE PISTONS Piston Kit 325027
JE PISTONS
$329.99When you're pushing your engine to the absolute limit—whether on the track or in competition—your pistons need to withstand extreme combustion pressures and temperatures without compromise. JE PISTONS 325027 Pro Series pistons are purpose-built for...09105941- SKU:
- 09105941
- Availability:
- Ships Same Business Day
- Weight:
- 1.36 LBS
- PISTON HEAD SHAPE:
- DOMED
- UNITS:
- KIT
- WALL THICKNESS IMPERIAL:
- 0.160'
- PRODUCT NAME:
- PISTON KIT
- RIDING STYLE:
- ATV
- WALL THICKNESS:
- 0,160'
- BORE SIZE METRIC:
- 99.00 MM
- DISPLACEMENT:
- 477 CC
- COMPRESSION RATIO IMPERIAL:
- 13.5:1
$329.99Qty in Cart: 0Quantity:Price:$329.99Subtotal: -
JE PISTONS Piston Kit 345054
JE PISTONS
$446.99When you're pushing your engine to the absolute limit—whether on the track or in competition—factory pistons simply won't cut it. JE PISTONS' 345054 kit delivers the strength, precision, and weight optimization that separates winners from the rest. Built...09105943- SKU:
- 09105943
- Availability:
- Ships Same Business Day
- Weight:
- 1.36 LBS
- BORE - OVERSIZE:
- STANDARD
- RIDING STYLE:
- OFF-ROAD
- STYLE:
- PRO SERIES
- UNITS:
- KIT
- PISTON HEAD SHAPE:
- DOMED
- TYPE:
- FORGED SIDE RELIEF DESIGN
- BORE - OVERSIZE METRIC:
- STANDARD
- BORE SIZE METRIC:
- 96.00 MM
- COMPRESSION RATIO IMPERIAL:
- 13.5:1
- DISPLACEMENT:
- 449 CC
- PISTON MATERIAL:
- FORGED 2618 ALUMINUM
- PRODUCT NAME:
- PISTON KIT
$446.99 -
JE PISTONS Piston Kit 345056
JE PISTONS
$446.99When you're pushing your engine to the absolute limit in competition, your pistons need to survive extreme pressures and temperatures without compromise. JE PISTONS' Pro Series 345056 kit delivers the precision engineering and materials science required...09105945- SKU:
- 09105945
- Availability:
- Ships Same Business Day
- Weight:
- 1.01 LBS
- BORE - OVERSIZE:
- STANDARD
- RIDING STYLE:
- OFF-ROAD
- STYLE:
- PRO SERIES
- UNITS:
- KIT
- BORE - OVERSIZE METRIC:
- STANDARD
- COMPRESSION RATIO IMPERIAL:
- 14.5:1
- PISTON HEAD SHAPE:
- DOMED
- PISTON MATERIAL:
- FORGED 2618 ALUMINUM
- TYPE:
- FORGED SIDE RELIEF DESIGN
- BORE SIZE METRIC:
- 96.00 MM
- DISPLACEMENT:
- 449 CC
- PRODUCT NAME:
- PISTON KIT
$446.99 -
JE PISTONS Piston Kit 345193
JE PISTONS
$839.99If you're running a high-displacement or boosted engine in a competition setting, you need pistons engineered to handle extreme pressure and heat cycles without compromise. JE PISTONS' Pro Series delivers the precision machining, internal bracing, and...09105947- SKU:
- 09105947
- Availability:
- Ships Same Business Day
- Weight:
- 2.66 LBS
- DISPLACEMENT:
- 998 CC
- UNITS:
- KIT
- BORE SIZE METRIC:
- 80.00 MM
- COMPRESSION RATIO IMPERIAL:
- 11.5:1
- PRODUCT NAME:
- PISTON KIT
- WALL THICKNESS:
- 0,160'
- WALL THICKNESS IMPERIAL:
- 0.160'
- PISTON HEAD SHAPE:
- DOMED
- RIDING STYLE:
- UTV
$839.99 -
JE PISTONS Piston Kit 345200
JE PISTONS
$424.99When you're pushing your engine to its limits in competition, your pistons need to withstand extreme pressures and temperatures without compromise. JE PISTONS' Pro Series 345200 kit delivers the precision engineering and durability demanded by...09105948- SKU:
- 09105948
- Availability:
- Ships Same Business Day
- Weight:
- 0.76 LBS
- BORE - OVERSIZE METRIC:
- STANDARD
- DISPLACEMENT:
- 249 CC
- PISTON MATERIAL:
- FORGED 2618 ALUMINUM
- BORE - OVERSIZE:
- STANDARD
- BORE SIZE METRIC:
- 77.00 MM
- PRODUCT NAME:
- PISTON KIT
- STYLE:
- PRO SERIES
- RIDING STYLE:
- OFF-ROAD
- COMPRESSION RATIO IMPERIAL:
- 14.0:1
- PISTON HEAD SHAPE:
- DOMED
- TYPE:
- FORGED SIDE RELIEF DESIGN
- UNITS:
- KIT
$424.99 -
JE PISTONS Piston Kit 345055
JE PISTONS
$446.99When you're pushing an engine to its absolute limits, stock pistons won't cut it. JE PISTONS 345055 Pro Series pistons are purpose-built for extreme competition applications, delivering the precision engineering and durability you need when every tenth...09105944- SKU:
- 09105944
- Availability:
- Ships Same Business Day
- Weight:
- 1.11 LBS
- BORE - OVERSIZE:
- STANDARD
- RIDING STYLE:
- OFF-ROAD
- STYLE:
- PRO SERIES
- PISTON MATERIAL:
- FORGED 2618 ALUMINUM
- TYPE:
- FORGED SIDE RELIEF DESIGN
- BORE - OVERSIZE METRIC:
- STANDARD
- COMPRESSION RATIO IMPERIAL:
- 14.0:1
- DISPLACEMENT:
- 449 CC
- PISTON HEAD SHAPE:
- DOMED
- UNITS:
- KIT
- BORE SIZE METRIC:
- 96.00 MM
- PRODUCT NAME:
- PISTON KIT
$446.99 -
JE PISTONS Piston Kit 130798
JE PISTONS
$269.99When you're pushing your engine to its limits in competition, factory pistons simply won't cut it. JE PISTONS' Pro Series kit delivers the precision engineering and material science required to survive extreme boost, high RPM, and sustained load—without...09105835- SKU:
- 09105835
- Availability:
- Ships Same Business Day
- Weight:
- 1.31 LBS
- DISPLACEMENT:
- 540 CC
- PISTON HEAD SHAPE:
- DOMED
- TYPE:
- ROUND FORGED DESIGN
- BORE - OVERSIZE METRIC:
- +3.00 MM
- PISTON MATERIAL:
- FORGED 2618 ALUMINUM
- PRODUCT NAME:
- PISTON KIT
- RIDING STYLE:
- STREET
- STYLE:
- JE PISTON
- BORE - OVERSIZE:
- +3,00 MM
- BORE SIZE METRIC:
- 90.00 MM
- COMPRESSION RATIO IMPERIAL:
- 11.0:1
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
$269.99Qty in Cart: 0Quantity:Price:$269.99Subtotal: -
On Sale
PROX Piston - GP 760 Waverunner 01.2514.050
PROX
MSRP: $138.95Now: $110.00Was: $138.95Piston for watercraft applications09102745- SKU:
- 09102745
- Availability:
- Ships Same Business Day
- Weight:
- 1.15 LBS
- BORE SIZE METRIC:
- 84.50 MM
- PRODUCT NAME:
- PISTON KIT
- UNITS:
- EACH
- ENGINE TYPE:
- 2-STROKE
- PISTON MATERIAL:
- ALUMINUM
- RIDING STYLE:
- WATERCRAFT
MSRP: $138.95Now: $110.00Was: $138.95 -
On Sale
PROX Piston - GP 760 Waverunner 01.2514.100
PROX
MSRP: $129.95Now: $110.00Was: $129.95Piston for watercraft applications09102747- SKU:
- 09102747
- Availability:
- Ships Same Business Day
- Weight:
- 1.10 LBS
- PRODUCT NAME:
- PISTON KIT
- RIDING STYLE:
- WATERCRAFT
- PISTON MATERIAL:
- ALUMINUM
- ENGINE TYPE:
- 2-STROKE
- UNITS:
- EACH
- BORE SIZE METRIC:
- 85.00 MM
MSRP: $129.95Now: $110.00Was: $129.95Qty in Cart: 0Quantity:Price:MSRP: $129.95Now: $110.00Was: $129.95Subtotal: -
On Sale
PROX Piston Kit - KTM300EXC '17-'18 01.6387.B
PROX
MSRP: $189.95Now: $161.00Was: $189.95When your KTM 300 EXC demands peak performance and reliability, OEM-spec pistons are non-negotiable. The PROX Piston Kit delivers factory-equivalent durability with precision Japanese engineering, ensuring consistent combustion, reduced blow-by, and...09106265- SKU:
- 09106265
- Availability:
- Ships Same Business Day
- Weight:
- 0.95 LBS
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- PRODUCT NAME:
- PISTON KIT
MSRP: $189.95Now: $161.00Was: $189.95Qty in Cart: 0Quantity:Price:MSRP: $189.95Now: $161.00Was: $189.95Subtotal: -
VERTEX Piston Kit 23870B
VERTEX
$353.95A piston kit is the foundation of engine reliability and performance—whether you're rebuilding after wear or upgrading for increased displacement and power. The VERTEX Piston Kit 23870B delivers the durability and precision needed for demanding...09103338- SKU:
- 09103338
- Availability:
- Ships Same Business Day
- Weight:
- 0.50 LBS
- RIDING STYLE:
- OFF-ROAD
- STYLE:
- FORGED HIGH COMPRESSION
- UNITS:
- KIT
- COMPRESSION RATIO IMPERIAL:
- 14.5:1
- CYLINDER DIAMETER METRIC:
- 78.00 MM
- DISPLACEMENT:
- 250 CC
- PRODUCT NAME:
- PISTON KIT
- RIDING STYLE:
- STREET
- PISTON DIAMETER METRIC:
- 77.97 MM
- ENGINE TYPE:
- 4-STROKE
- PISTON MATERIAL:
- FORGED 2618 ALUMINUM
- SKIRT COATING:
- MOLYBDENUM DISULPHITE
$353.95 -
VERTEX Piston Kit 23925B
VERTEX
$289.95If you're building or rebuilding an engine for serious duty—whether on the track or in competition—piston quality directly impacts reliability and performance longevity. The VERTEX Piston Kit 23925B delivers the metallurgical precision and surface...09103341- SKU:
- 09103341
- Availability:
- Ships Same Business Day
- Weight:
- 0.58 LBS
- CYLINDER DIAMETER METRIC:
- 80.00 MM
- BORE - OVERSIZE:
- +3,00 MM
- PISTON MATERIAL:
- FORGED 2618 ALUMINUM
- STYLE:
- FORGED BIG BORE
- COMPRESSION RATIO IMPERIAL:
- 13.5:1
- ENGINE TYPE:
- 4-STROKE
- BORE - OVERSIZE METRIC:
- +3.00 MM
- DISPLACEMENT:
- 270 CC
- PISTON DIAMETER METRIC:
- 79.96 MM
- PRODUCT NAME:
- PISTON KIT
- RIDING STYLE:
- OFF-ROAD
- SKIRT COATING:
- MOLYBDENUM DISULPHITE
- UNITS:
- KIT
$289.95 -
VERTEX Piston Kit 23119100
VERTEX
$170.95Whether you're rebuilding a worn top end or upgrading to higher compression, the VERTEX Piston Kit 23119100 delivers the durability and performance you need to stay competitive. VERTEX pistons undergo rigorous heat treatment and precision manufacturing...09103343- SKU:
- 09103343
- Availability:
- Ships Same Business Day
- Weight:
- 0.40 LBS
- BORE - OVERSIZE:
- +1,00 MM
- BORE - OVERSIZE METRIC:
- +1.00 MM
- PISTON MATERIAL:
- CAST
- PRODUCT NAME:
- PISTON KIT
- UNITS:
- KIT
- COMPRESSION RATIO IMPERIAL:
- STANDARD
- RIDING STYLE:
- OFF-ROAD
- STYLE:
- CAST BIG BORE
- DISPLACEMENT:
- 130 CC
- ENGINE TYPE:
- 2-STROKE
- PISTON MATERIAL:
- ALUMINUM ALLOY
- SKIRT COATING:
- MOLYBDENUM DISULPHITE
- CYLINDER DIAMETER METRIC:
- 55.00 MM
- PISTON DIAMETER METRIC:
- 54.95 MM
$170.95Qty in Cart: 0Quantity:Price:$170.95Subtotal: -
VERTEX Piston Kit 23941A
VERTEX
$230.95A quality piston kit is fundamental to engine reliability and performance, especially under high-load conditions. The VERTEX Piston Kit 23941A delivers durability through advanced heat treatment and a specialized coating designed to reduce friction...09103345- SKU:
- 09103345
- Availability:
- Ships Same Business Day
- Weight:
- 0.55 LBS
$230.95 -
VERTEX Piston Kit with Gaskets VTK22521B
VERTEX
$289.95If you're serious about extracting maximum power and reliability from your engine, pistons are where precision matters most. The VERTEX Piston Kit delivers forged high-compression geometry that increases power and torque across the entire RPM band, while...09103362- SKU:
- 09103362
- Availability:
- Ships Same Business Day
- Weight:
- 1.15 LBS
- CYLINDER DIAMETER METRIC:
- 66.40 MM
- PISTON MATERIAL:
- ALUMINUM ALLOY
- SKIRT COATING:
- MOLYBDENUM DISULPHITE
- PRODUCT NAME:
- TOP END PISTON KIT
- STYLE:
- CAST REPLICA
- DISPLACEMENT:
- 250 CC
- ENGINE TYPE:
- 2-STROKE
- PISTON DIAMETER METRIC:
- 66.36 MM
- PISTON MATERIAL:
- CAST
- COMPRESSION RATIO IMPERIAL:
- STANDARD
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
$289.95 -
VERTEX Piston Kit with Gaskets VTK22652B
VERTEX
$223.95Whether you're rebuilding a high-mileage engine or upgrading to a higher-compression setup, the VERTEX Piston Kit VTK22652B delivers the durability and performance you need for reliable power gains. VERTEX's forged 2618 aluminum construction and advanced...09103375- SKU:
- 09103375
- Availability:
- Ships Same Business Day
- Weight:
- 0.80 LBS
- PISTON MATERIAL:
- CAST
- PRODUCT NAME:
- TOP END PISTON KIT
- DISPLACEMENT:
- 125 CC
- COMPRESSION RATIO IMPERIAL:
- STANDARD
- CYLINDER DIAMETER METRIC:
- 54.00 MM
- PISTON DIAMETER METRIC:
- 53.96 MM
- PISTON MATERIAL:
- ALUMINUM ALLOY
- RIDING STYLE:
- OFF-ROAD
- SKIRT COATING:
- MOLYBDENUM DISULPHITE
- UNITS:
- KIT
- ENGINE TYPE:
- 2-STROKE
- STYLE:
- CAST REPLICA
$223.95 -
VERTEX Piston Kit with Gaskets VTK22806B
VERTEX
$208.95A piston kit is foundational to engine reliability and performance—this VERTEX kit delivers the precision engineering and durability required for sustained high-RPM operation. The T-5 heat treatment cycle ensures consistent hardness and fatigue...09103380- SKU:
- 09103380
- Availability:
- Ships Same Business Day
- Weight:
- 0.95 LBS
- DISPLACEMENT:
- 125 CC
- PISTON MATERIAL:
- ALUMINUM ALLOY
- SKIRT COATING:
- MOLYBDENUM DISULPHITE
- ENGINE TYPE:
- 2-STROKE
- COMPRESSION RATIO IMPERIAL:
- STANDARD
- CYLINDER DIAMETER METRIC:
- 54.00 MM
- PRODUCT NAME:
- TOP END PISTON KIT
- STYLE:
- CAST REPLICA
- PISTON DIAMETER METRIC:
- 53.94 MM
- PISTON MATERIAL:
- CAST
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
$208.95 -
VERTEX Piston Kit VTK23124B
VERTEX
$289.95Precision-engineered pistons are the heart of any high-performance engine build, and the VERTEX Piston Kit VTK23124B delivers the durability and reliability demanded by serious racers and performance enthusiasts. Built with advanced heat-treatment...09103074- SKU:
- 09103074
- Availability:
- Ships Same Business Day
- Weight:
- 1.30 LBS
- COMPRESSION RATIO IMPERIAL:
- STANDARD
- ENGINE TYPE:
- 2-STROKE
- RIDING STYLE:
- OFF-ROAD
- STYLE:
- CAST REPLICA
- PISTON DIAMETER METRIC:
- 66.36 MM
- PISTON MATERIAL:
- ALUMINUM ALLOY
- PISTON MATERIAL:
- CAST
- SKIRT COATING:
- MOLYBDENUM DISULPHITE
- UNITS:
- KIT
- CYLINDER DIAMETER METRIC:
- 66.40 MM
- DISPLACEMENT:
- 250 CC
- PRODUCT NAME:
- TOP END PISTON KIT
$289.95Qty in Cart: 0Quantity:Price:$289.95Subtotal: -
VERTEX Piston Kit VTK22860B
VERTEX
$184.95The VERTEX Piston Kit VTK22860B delivers the precision and durability required for high-RPM engine builds. Purpose-engineered with heat-treated construction and a molybdenum disulfide coating, these pistons minimize friction during critical break-in...09103081- SKU:
- 09103081
- Availability:
- Ships Same Business Day
- Weight:
- 1.00 LBS
- COMPRESSION RATIO IMPERIAL:
- STANDARD
- CYLINDER DIAMETER METRIC:
- 44.50 MM
- UNITS:
- KIT
- ENGINE TYPE:
- 2-STROKE
- PISTON MATERIAL:
- CAST
- DISPLACEMENT:
- 65 CC
- PISTON DIAMETER METRIC:
- 44.45 MM
- PRODUCT NAME:
- TOP END PISTON KIT
- RIDING STYLE:
- OFF-ROAD
- STYLE:
- CAST REPLICA
- PISTON MATERIAL:
- ALUMINUM ALLOY
- SKIRT COATING:
- MOLYBDENUM DISULPHITE
$184.95 -
VERTEX Piston Kit VTK22803B
VERTEX
$184.95A quality piston kit is fundamental to engine reliability and performance—especially under high RPM and boost conditions. The VERTEX Piston Kit VTK22803B combines precision engineering with proven durability treatments that reduce friction and extend...09103082- SKU:
- 09103082
- Availability:
- Ships Same Business Day
- Weight:
- 0.90 LBS
- COMPRESSION RATIO IMPERIAL:
- STANDARD
- DISPLACEMENT:
- 85 CC
- STYLE:
- CAST REPLICA
- PISTON DIAMETER METRIC:
- 48.45 MM
- PRODUCT NAME:
- TOP END PISTON KIT
- RIDING STYLE:
- OFF-ROAD
- ENGINE TYPE:
- 2-STROKE
- PISTON MATERIAL:
- ALUMINUM ALLOY
- PISTON MATERIAL:
- CAST
- SKIRT COATING:
- MOLYBDENUM DISULPHITE
- UNITS:
- KIT
- CYLINDER DIAMETER METRIC:
- 48.50 MM
$184.95
