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
-
On Sale
PROX Piston Kit 01.2215.B
PROX
MSRP: $105.95Now: $90.00Was: $105.95Your engine's pistons are the hardworking heart of combustion—and worn or damaged units directly compromise power output, efficiency, and reliability. The PROX Piston Kit 01.2215.B delivers OEM-equivalent performance with precision engineering you can...PX7214B- SKU:
- PX7214B
- Availability:
- Ships Same Business Day
- Weight:
- 0.44 LBS
- BORE SIZE METRIC:
- 53.95 MM
- ENGINE TYPE:
- 2-STROKE
- PISTON SIZE METRIC:
- +0.01 MM
- PISTON DIAMETER METRIC:
- 53.95 MM
- PISTON MATERIAL:
- ALUMINUM ALLOY
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- EACH
- PRODUCT NAME:
- PISTON KIT
MSRP: $105.95Now: $90.00Was: $105.95Qty in Cart: 0Quantity:Price:MSRP: $105.95Now: $90.00Was: $105.95Subtotal: -
On Sale
PROX Piston Kit 01.4223.A
PROX
MSRP: $101.95Now: $87.00Was: $101.95When your engine demands precision and reliability, OEM-spec pistons are non-negotiable. The PROX Piston Kit 01.4223.A delivers factory-matched performance with CNC-machined accuracy, ensuring consistent compression, reduced blow-by, and extended engine...09100024- SKU:
- 09100024
- Availability:
- Ships Same Business Day
- Weight:
- 0.25 LBS
- PISTON DIAMETER METRIC:
- 53.95 MM
- PISTON MATERIAL:
- ALUMINUM ALLOY
- PRODUCT NAME:
- PISTON KIT
- UNITS:
- EACH
- PISTON SIZE METRIC:
- STANDARD SIZE A
- BORE SIZE METRIC:
- 53.95 MM
- ENGINE TYPE:
- 2-STROKE
- RIDING STYLE:
- OFF-ROAD
MSRP: $101.95Now: $87.00Was: $101.95Qty in Cart: 0Quantity:Price:MSRP: $101.95Now: $87.00Was: $101.95Subtotal: -
On Sale
PROX Piston Kit 01.1414.A
PROX
MSRP: $210.95Now: $167.00Was: $210.95When your engine demands reliability under extreme conditions, OEM-spec pistons aren't optional—they're foundational. The PROX Piston Kit 01.1414.A delivers factory-engineered performance with precision machining that eliminates the guesswork of...09100607- SKU:
- 09100607
- Availability:
- Ships Same Business Day
- Weight:
- 0.81 LBS
- BORE SIZE METRIC:
- 95.96 MM
- PISTON DIAMETER METRIC:
- 95.96 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
MSRP: $210.95Now: $167.00Was: $210.95Qty in Cart: 0Quantity:Price:MSRP: $210.95Now: $167.00Was: $210.95Subtotal: -
On Sale
PROX Piston Kit 01.1338.B
PROX
MSRP: $188.95Now: $158.00Was: $188.95Worn or damaged pistons compromise engine efficiency, power delivery, and long-term reliability—especially under racing conditions or high-mileage operation. The PROX Piston Kit 01.1338.B restores your engine to OEM specification with...09101127- SKU:
- 09101127
- Availability:
- Ships Same Business Day
- Weight:
- 0.50 LBS
- ENGINE TYPE:
- 4-STROKE
- PISTON MATERIAL:
- ALUMINUM ALLOY
- UNITS:
- EACH
- RIDING STYLE:
- OFF-ROAD
- PISTON DIAMETER METRIC:
- 77.98 MM
- BORE SIZE METRIC:
- 77.98 MM
- PISTON SIZE METRIC:
- STANDARD
- PRODUCT NAME:
- PISTON KIT
MSRP: $188.95Now: $158.00Was: $188.95 -
On Sale
PROX Piston Kit 01.1320.A2
PROX
MSRP: $139.95Now: $119.00Was: $139.95When your engine is the heartbeat of your vehicle, piston quality directly impacts reliability, power delivery, and longevity. The PROX Piston Kit 01.1320.A2 delivers OEM-equivalent performance without compromise, engineered with precision manufacturing...PX4430C- SKU:
- PX4430C
- Availability:
- Ships Same Business Day
- Weight:
- 0.70 LBS
- RIDING STYLE:
- OFF-ROAD
- PISTON DIAMETER METRIC:
- 66.36 MM
- PISTON SIZE METRIC:
- STANDARD SIZE A
- BORE SIZE METRIC:
- 66.36 MM
- PRODUCT NAME:
- PISTON KIT
- PISTON MATERIAL:
- ALUMINUM ALLOY
- UNITS:
- EACH
MSRP: $139.95Now: $119.00Was: $139.95Qty in Cart: 0Quantity:Price:MSRP: $139.95Now: $119.00Was: $139.95Subtotal: -
On Sale
VERTEX Piston Kit 24220B
VERTEX
MSRP: $269.95Now: $173.00Was: $269.95The VERTEX Piston Kit 24220B delivers the durability and precision your engine demands, whether you're pushing peak RPMs on the track or rebuilding after hard use. Built with advanced metallurgy and factory-grade coatings, these pistons reduce break-in...09105190- SKU:
- 09105190
- Availability:
- Ships Same Business Day
- Weight:
- 0.55 LBS
- COMPRESSION RATIO IMPERIAL:
- 13.7:1
- DISPLACEMENT:
- 250 CC
- RIDING STYLE:
- OFF-ROAD
- STYLE:
- FORGED HIGH COMPRESSION
- UNITS:
- KIT
- PISTON DIAMETER METRIC:
- 76.96 MM
- PISTON MATERIAL:
- FORGED 2618 ALUMINUM
- PRODUCT NAME:
- PISTON KIT
- CYLINDER DIAMETER METRIC:
- 77.00 MM
- ENGINE TYPE:
- 4-STROKE
- SKIRT COATING:
- MOLYBDENUM DISULPHITE
MSRP: $269.95Now: $173.00Was: $269.95 -
VERTEX Piston Kit 24101A
VERTEX
$223.95The VERTEX Piston Kit 24101A delivers the precision engineering and durability demanded by serious racers and high-performance builders. Whether you're rebuilding a worn engine or pushing displacement and compression, this kit provides the exact...09104070- SKU:
- 09104070
- Availability:
- Ships Same Business Day
- Weight:
- 0.60 LBS
- PISTON MATERIAL:
- ALUMINUM ALLOY
- SKIRT COATING:
- MOLYBDENUM DISULPHITE
- STYLE:
- CAST REPLICA
- DISPLACEMENT:
- 150 CC
- ENGINE TYPE:
- 2-STROKE
- PRODUCT NAME:
- PISTON KIT
- CYLINDER DIAMETER METRIC:
- 58 MM
- PISTON DIAMETER METRIC:
- 57.94 MM
- COMPRESSION RATIO IMPERIAL:
- STANDARD
- PISTON MATERIAL:
- CAST
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
$223.95Qty in Cart: 0Quantity:Price:$223.95Subtotal: -
VERTEX Piston Kit 24097A
VERTEX
$302.95A piston kit is only as good as its metallurgy and surface treatment—and VERTEX's 24097A delivers on both fronts. The T-5 heat treatment cycle ensures consistent hardness and durability under extreme combustion pressures, while the Molybdenum Disulphite...09104076- SKU:
- 09104076
- Availability:
- Ships Same Business Day
- Weight:
- 0.50 LBS
$302.95 -
VERTEX Piston Kit 24122B
VERTEX
$256.95Whether you're building a race engine or refreshing a high-mileage platform, piston durability is non-negotiable. The VERTEX Piston Kit 24122B delivers the material science and precision engineering needed to withstand sustained high-RPM operation and...09104087- SKU:
- 09104087
- Availability:
- Ships Same Business Day
- Weight:
- 0.55 LBS
$256.95Qty in Cart: 0Quantity:Price:$256.95Subtotal: -
VERTEX Piston Kit 24099A
VERTEX
$302.95If you're building or rebuilding an engine that demands reliability under extreme conditions, the VERTEX Piston Kit 24099A delivers the precision-engineered durability required for sustained high-RPM performance. The advanced T-5 heat treatment process...09104107- SKU:
- 09104107
- Availability:
- Ships Same Business Day
- Weight:
- 0.90 LBS
- CYLINDER DIAMETER METRIC:
- 95.00 MM
- PISTON MATERIAL:
- FORGED 2618 ALUMINUM
- COMPRESSION RATIO IMPERIAL:
- 12.6:1
- ENGINE TYPE:
- 4-STROKE
- PISTON DIAMETER METRIC:
- 94.95 MM
- PRODUCT NAME:
- PISTON KIT
- SKIRT COATING:
- MOLYBDENUM DISULPHITE
- DISPLACEMENT:
- 450 CC
- RIDING STYLE:
- OFF-ROAD
- RIDING STYLE:
- STREET
- STYLE:
- FORGED HIGH COMPRESSION
- UNITS:
- KIT
$302.95 -
VERTEX Piston Kit 24099B
VERTEX
$302.95A piston kit is only as good as its metallurgy and surface treatment—this is where engine reliability lives or dies. The VERTEX Piston Kit 24099B delivers heat-treated construction and a molybdenum disulfide coating that reduce friction during critical...09104108- SKU:
- 09104108
- Availability:
- Ships Same Business Day
- Weight:
- 0.85 LBS
- CYLINDER DIAMETER METRIC:
- 95.00 MM
- PISTON DIAMETER METRIC:
- 94.96 MM
- PISTON MATERIAL:
- FORGED 2618 ALUMINUM
- DISPLACEMENT:
- 450 CC
- COMPRESSION RATIO IMPERIAL:
- 12.6:1
- ENGINE TYPE:
- 4-STROKE
- PRODUCT NAME:
- PISTON KIT
- RIDING STYLE:
- STREET
- SKIRT COATING:
- MOLYBDENUM DISULPHITE
- RIDING STYLE:
- OFF-ROAD
- STYLE:
- FORGED HIGH COMPRESSION
- UNITS:
- KIT
$302.95 -
VERTEX Piston Kit 24098A
VERTEX
$293.95A quality piston kit is the foundation of engine reliability and performance—cheap pistons will fail under boost or high RPM, costing you time and money. The VERTEX Piston Kit 24098A combines advanced heat treatment and low-friction coatings to deliver...09104110- SKU:
- 09104110
- Availability:
- Ships Same Business Day
- Weight:
- 0.65 LBS
$293.95 -
VERTEX Piston Kit 23941B
VERTEX
$230.95A piston kit is fundamental to engine reliability and performance—especially under high RPM and boost conditions where factory pistons often fall short. The VERTEX Piston Kit 23941B combines heat-treated strength with a molybdenum disulfide skirt coating...09103346- SKU:
- 09103346
- Availability:
- Ships Same Business Day
- Weight:
- 0.55 LBS
$230.95Qty in Cart: 0Quantity:Price:$230.95Subtotal: -
On Sale
VERTEX Piston Kit 23942A
VERTEX
MSRP: $236.95Now: $152.00Was: $236.95A quality piston kit is the foundation of engine reliability, especially when you're pushing performance boundaries. The VERTEX Piston Kit 23942A delivers the durability and precision needed for sustained high-RPM operation, with metallurgical...09103348- SKU:
- 09103348
- Availability:
- Ships Same Business Day
- Weight:
- 0.50 LBS
- CYLINDER DIAMETER METRIC:
- 77.00 MM
- PISTON DIAMETER METRIC:
- 76.95 MM
- PISTON MATERIAL:
- FORGED 2618 ALUMINUM
- SKIRT COATING:
- MOLYBDENUM DISULPHITE
- RIDING STYLE:
- OFF-ROAD
- STYLE:
- FORGED HIGH COMPRESSION
- UNITS:
- KIT
- COMPRESSION RATIO IMPERIAL:
- 14.2:1
- DISPLACEMENT:
- 250 CC
- ENGINE TYPE:
- 4-STROKE
- PRODUCT NAME:
- PISTON KIT
MSRP: $236.95Now: $152.00Was: $236.95 -
On Sale
VERTEX Piston Kit 23942B
VERTEX
MSRP: $236.95Now: $152.00Was: $236.95If you're building or rebuilding an engine that demands reliability under extreme conditions, piston quality directly impacts your power output and engine longevity. The VERTEX Piston Kit 23942B delivers the metallurgical precision and surface...09103349- SKU:
- 09103349
- Availability:
- Ships Same Business Day
- Weight:
- 0.55 LBS
- DISPLACEMENT:
- 250 CC
- COMPRESSION RATIO IMPERIAL:
- 14.2:1
- ENGINE TYPE:
- 4-STROKE
- PISTON DIAMETER METRIC:
- 76.96 MM
- PRODUCT NAME:
- PISTON KIT
- SKIRT COATING:
- MOLYBDENUM DISULPHITE
- STYLE:
- FORGED HIGH COMPRESSION
- UNITS:
- KIT
- RIDING STYLE:
- OFF-ROAD
- CYLINDER DIAMETER METRIC:
- 77.00 MM
- PISTON MATERIAL:
- FORGED 2618 ALUMINUM
MSRP: $236.95Now: $152.00Was: $236.95 -
VERTEX Piston Kit 23942C
VERTEX
$189.95High-performance pistons demand precision engineering and material science that goes beyond standard OEM specifications. The VERTEX Piston Kit 23942C delivers the durability and low-friction characteristics needed for sustained high-RPM operation,...09103350- SKU:
- 09103350
- Availability:
- Ships Same Business Day
- Weight:
- 0.55 LBS
- CYLINDER DIAMETER METRIC:
- 77.00 MM
- PISTON MATERIAL:
- FORGED 2618 ALUMINUM
- SKIRT COATING:
- MOLYBDENUM DISULPHITE
- COMPRESSION RATIO IMPERIAL:
- 14.2:1
- DISPLACEMENT:
- 250 CC
- ENGINE TYPE:
- 4-STROKE
- PRODUCT NAME:
- PISTON KIT
- RIDING STYLE:
- OFF-ROAD
- STYLE:
- FORGED HIGH COMPRESSION
- UNITS:
- KIT
- PISTON DIAMETER METRIC:
- 76.97 MM
$189.95Qty in Cart: 0Quantity:Price:$189.95Subtotal: -
VERTEX Piston Kit 23943A
VERTEX
$302.95When your engine is operating at peak RPM, piston reliability becomes non-negotiable. The VERTEX Piston Kit 23943A delivers the durability and precision required for sustained high-performance operation, whether you're on the track or pushing your build...09103354- SKU:
- 09103354
- Availability:
- Ships Same Business Day
- Weight:
- 0.57 LBS
- BORE - OVERSIZE:
- +3,00 MM
- COMPRESSION RATIO IMPERIAL:
- 13.5:1
- ENGINE TYPE:
- 4-STROKE
- PISTON MATERIAL:
- FORGED 2618 ALUMINUM
- BORE - OVERSIZE METRIC:
- +3.00 MM
- STYLE:
- FORGED BIG BORE
- PISTON DIAMETER METRIC:
- 79.96 MM
- PRODUCT NAME:
- PISTON KIT
- CYLINDER DIAMETER METRIC:
- 80.00 MM
- DISPLACEMENT:
- 270 CC
- RIDING STYLE:
- OFF-ROAD
- SKIRT COATING:
- MOLYBDENUM DISULPHITE
- UNITS:
- KIT
$302.95Qty in Cart: 0Quantity:Price:$302.95Subtotal: -
VERTEX Piston Kit 23943B
VERTEX
$302.95A piston kit is only as good as its material science and thermal treatment—and the VERTEX 23943B delivers on both fronts. If you're building or rebuilding an engine that demands reliability under sustained high RPM and cylinder pressures, this kit...09103355- SKU:
- 09103355
- Availability:
- Ships Same Business Day
- Weight:
- 0.57 LBS
- BORE - OVERSIZE METRIC:
- +3.00 MM
- COMPRESSION RATIO IMPERIAL:
- 13.5:1
- ENGINE TYPE:
- 4-STROKE
- PISTON DIAMETER METRIC:
- 79.97 MM
- PISTON MATERIAL:
- FORGED 2618 ALUMINUM
- SKIRT COATING:
- MOLYBDENUM DISULPHITE
- STYLE:
- FORGED BIG BORE
- BORE - OVERSIZE:
- +3,00 MM
- CYLINDER DIAMETER METRIC:
- 80.00 MM
- DISPLACEMENT:
- 270 CC
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- PRODUCT NAME:
- PISTON KIT
$302.95 -
VERTEX Piston Kit with Gaskets VTK22189B
VERTEX
$189.95A piston kit is the foundation of reliable top-end performance—whether you're rebuilding after wear or upgrading for more power. The VERTEX VTK22189B delivers the durability and precision demanded by racers and serious enthusiasts, combining advanced...09103357- SKU:
- 09103357
- Availability:
- Ships Same Business Day
- Weight:
- 0.90 LBS
- DISPLACEMENT:
- 125 CC
- ENGINE TYPE:
- 2-STROKE
- PISTON MATERIAL:
- ALUMINUM ALLOY
- SKIRT COATING:
- MOLYBDENUM DISULPHITE
- STYLE:
- CAST REPLICA
- COMPRESSION RATIO IMPERIAL:
- STANDARD
- CYLINDER DIAMETER METRIC:
- 54.00 MM
- RIDING STYLE:
- OFF-ROAD
- PISTON DIAMETER METRIC:
- 53.94 MM
- PISTON MATERIAL:
- CAST
- PRODUCT NAME:
- TOP END PISTON KIT
- UNITS:
- KIT
$189.95Qty in Cart: 0Quantity:Price:$189.95Subtotal: -
VERTEX Piston Kit with Gaskets VTK22189B-1
VERTEX
$202.95Engine longevity and peak performance depend on pistons engineered to withstand extreme combustion pressures and thermal cycling. The VERTEX Piston Kit VTK22189B-1 delivers factory-grade reliability with forged 2618 aluminum construction, ensuring your...09103358- SKU:
- 09103358
- Availability:
- Ships Same Business Day
- Weight:
- 0.90 LBS
- ENGINE TYPE:
- 2-STROKE
- STYLE:
- CAST REPLICA
- DISPLACEMENT:
- 125 CC
- PISTON MATERIAL:
- CAST
- COMPRESSION RATIO IMPERIAL:
- STANDARD
- CYLINDER DIAMETER METRIC:
- 54.00 MM
- PISTON DIAMETER METRIC:
- 53.94 MM
- PISTON MATERIAL:
- ALUMINUM ALLOY
- RIDING STYLE:
- OFF-ROAD
- SKIRT COATING:
- MOLYBDENUM DISULPHITE
- UNITS:
- KIT
- PRODUCT NAME:
- TOP END PISTON KIT
$202.95
