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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VERTEX Piston Kit 23205500
VERTEX
$165.95A precision piston kit designed for builders who demand reliability under extreme combustion pressures and extended engine cycles. The VERTEX 23205500 combines metallurgical excellence with a low-friction skirt coating to minimize wear during critical...09102076- SKU:
- 09102076
- Availability:
- Ships Same Business Day
- Weight:
- 0.42 LBS
- COMPRESSION RATIO IMPERIAL:
- STANDARD
- CYLINDER DIAMETER METRIC:
- 53.00 MM
- STYLE:
- CAST BIG BORE
- UNITS:
- KIT
- BORE - OVERSIZE:
- +5,00 MM
- BORE - OVERSIZE METRIC:
- +5.00 MM
- RIDING STYLE:
- OFF-ROAD
- DISPLACEMENT:
- 103 CC
- ENGINE TYPE:
- 2-STROKE
- PISTON MATERIAL:
- CAST
- PRODUCT NAME:
- PISTON KIT
- PISTON DIAMETER METRIC:
- 52.95 MM
- PISTON MATERIAL:
- ALUMINUM ALLOY
- SKIRT COATING:
- MOLYBDENUM DISULPHITE
$165.95Qty in Cart: 0Quantity:Price:$165.95Subtotal: -
VERTEX Piston Kit 23329B
VERTEX
$302.95A piston kit is only as good as its heat treatment and surface preparation—two areas where VERTEX doesn't compromise. The 23329B delivers the durability and reliability you need for sustained high-RPM performance, whether you're building a race engine or...09101007- SKU:
- 09101007
- Availability:
- Ships Same Business Day
- Weight:
- 0.88 LBS
$302.95 -
VERTEX Piston Kit - Standard 22541B
VERTEX
$302.95Precision piston construction directly impacts engine reliability, power delivery, and longevity under sustained racing conditions. The VERTEX Piston Kit 22541B combines advanced heat treatment with a specialized skirt coating to minimize friction during...09101003- SKU:
- 09101003
- Availability:
- Ships Same Business Day
- Weight:
- 0.93 LBS
- COMPRESSION RATIO IMPERIAL:
- STANDARD
- PISTON DIAMETER METRIC:
- 77.95 MM
- PISTON MATERIAL:
- CAST
- PRODUCT NAME:
- PISTON KIT
- UNITS:
- KIT
- ENGINE TYPE:
- 2-STROKE
- CYLINDER DIAMETER METRIC:
- 78.00 MM
- DISPLACEMENT:
- 360 CC
- PISTON MATERIAL:
- ALUMINUM ALLOY
- RIDING STYLE:
- OFF-ROAD
- SKIRT COATING:
- MOLYBDENUM DISULPHITE
- STYLE:
- CAST REPLICA
$302.95Qty in Cart: 0Quantity:Price:$302.95Subtotal: -
On Sale
ATHENA Piston Kit S4F06600002C
ATHENA
MSRP: $109.95Now: $99.00Was: $109.95The ATHENA Piston Kit S4F06600002C delivers the precision and durability demanded by competitive racers and serious engine builders. Built from the same 2618 silicium alloy used in Formula 1 powerplants, these forged pistons withstand extreme combustion...09100452- SKU:
- 09100452
- Availability:
- Ships Same Business Day
- Weight:
- 0.62 LBS
- ENGINE TYPE:
- 2-STROKE
- PISTON MATERIAL:
- 4032 ALUMINUM ALLOY
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- BORE SIZE METRIC:
- 65.96 MM
- DISPLACEMENT:
- 198 CC
- PISTON HEAD SHAPE:
- FLAT TOP
- TYPE:
- C
- COMPRESSION RATIO IMPERIAL:
- STOCK
- PRODUCT NAME:
- PISTON KIT
MSRP: $109.95Now: $99.00Was: $109.95Qty in Cart: 0Quantity:Price:MSRP: $109.95Now: $99.00Was: $109.95Subtotal: -
On Sale
ATHENA Piston Kit S4C05400010A
ATHENA
MSRP: $120.95Now: $109.00Was: $120.95A quality piston kit is the foundation of reliable engine performance, directly affecting compression, durability, and power delivery. The ATHENA Piston Kit S4C05400010A delivers precision-engineered components manufactured to exact tolerances, ensuring...09100253- SKU:
- 09100253
- Availability:
- Ships Same Business Day
- Weight:
- 0.40 LBS
- ENGINE TYPE:
- 2-STROKE
- PISTON DIAMETER METRIC:
- 53.94 MM
- PISTON SIZE METRIC:
- STANDARD SIZE A
- STYLE:
- STANDARD BORE
- UNITS:
- EACH
- COMPRESSION RATIO IMPERIAL:
- 14.8:1
- RIDING STYLE:
- OFF-ROAD
- PRODUCT NAME:
- PISTON
MSRP: $120.95Now: $109.00Was: $120.95Qty in Cart: 0Quantity:Price:MSRP: $120.95Now: $109.00Was: $120.95Subtotal: -
On Sale
ATHENA Piston Kit S4F07200001A
ATHENA
MSRP: $225.95Now: $203.00Was: $225.95Precision matters when you're pushing your engine to its limits. The ATHENA Piston Kit S4F07200001A delivers the same metallurgical engineering found in Formula 1 powerplants, engineered with forged construction and heat-treated tolerances of just .005mm...09100172- SKU:
- 09100172
- Availability:
- Ships Same Business Day
- Weight:
- 0.60 LBS
- PRODUCT NAME:
- PISTON KIT
- TYPE:
- A
- BORE SIZE METRIC:
- 71.93 MM
- PISTON HEAD SHAPE:
- FLAT TOP
- COMPRESSION RATIO IMPERIAL:
- STOCK
- DISPLACEMENT:
- 300 CC
- ENGINE TYPE:
- 2-STROKE
- PISTON MATERIAL:
- 4032 ALUMINUM ALLOY
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
MSRP: $225.95Now: $203.00Was: $225.95Qty in Cart: 0Quantity:Price:MSRP: $225.95Now: $203.00Was: $225.95Subtotal: -
On Sale
ATHENA Piston Kit S4F06640007A
ATHENA
MSRP: $164.95Now: $148.00Was: $164.95Maximum engine reliability demands pistons engineered to withstand extreme combustion pressures and thermal cycling without compromise. The ATHENA Piston Kit S4F06640007A delivers the precision and durability found in Formula 1 competition engines, using...09100131- SKU:
- 09100131
- Availability:
- Ships Same Business Day
- Weight:
- 0.62 LBS
- COMPRESSION RATIO IMPERIAL:
- STOCK
- ENGINE TYPE:
- 2-STROKE
- PISTON MATERIAL:
- 4032 ALUMINUM ALLOY
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- BORE SIZE METRIC:
- 66.34 MM
- PISTON HEAD SHAPE:
- FLAT TOP
- DISPLACEMENT:
- 250 CC
- PRODUCT NAME:
- PISTON KIT
- TYPE:
- A
MSRP: $164.95Now: $148.00Was: $164.95Qty in Cart: 0Quantity:Price:MSRP: $164.95Now: $148.00Was: $164.95Subtotal: -
Wiseco 56mm Piston Kit with Gaskets for KTM 125 SX 2002-2006 PK1513
WISECO
$234.95When your KTM 125 SX's top-end reaches the end of its service life, a quality piston kit is non-negotiable. Wiseco's PK1513 delivers the precision engineering and material quality you need to restore full engine performance and reliability. This complete...09030700- SKU:
- 09030700
- Availability:
- Ships Same Business Day
- Weight:
- 0.95 LBS
- PISTON MATERIAL:
- 4032 ALUMINUM ALLOY
- STROKE LENGTH METRIC:
- 54.00 MM
- BORE - OVERSIZE METRIC:
- +2.00 MM
- DISPLACEMENT:
- 124 CC
- ENGINE TYPE:
- 2-STROKE
- MODEL:
- PRO-LITE
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- BORE - OVERSIZE:
- +2,00 MM
- PISTON DIAMETER METRIC:
- 55.95 MM
- TYPE:
- TOP END
- BORE SIZE METRIC:
- 56.00 MM
- PISTON SIZE METRIC:
- +2.00 MM
- PRODUCT NAME:
- REBUILD KIT
- SKIRT COATING:
- ARMORGLIDE®
$234.95Qty in Cart: 0Quantity:Price:$234.95Subtotal: -
On Sale
PROX Piston Kit 01.1408.200
PROX
MSRP: $185.95Now: $158.00Was: $185.95Worn or damaged pistons compromise engine efficiency, reliability, and performance—especially in high-stress racing applications. The PROX Piston Kit 011408200 restores your engine to OEM specifications with precision-engineered components manufactured...09030821- SKU:
- 09030821
- Availability:
- Ships Same Business Day
- Weight:
- 1.35 LBS
- RIDING STYLE:
- OFF-ROAD
- BORE SIZE METRIC:
- 91.00 MM
- PISTON MATERIAL:
- ALUMINUM ALLOY
- PISTON SIZE METRIC:
- +2.00 MM
- TYPE:
- TOP END
- UNITS:
- EACH
- ENGINE TYPE:
- 2-STROKE
- PRODUCT NAME:
- PISTON KIT
MSRP: $185.95Now: $158.00Was: $185.95Qty in Cart: 0Quantity:Price:MSRP: $185.95Now: $158.00Was: $185.95Subtotal: -
VERTEX Piston Kit - Standard 22877B
VERTEX
$127.95Precision-engineered pistons are the foundation of reliable high-RPM performance, and the VERTEX Piston Kit 22877B delivers the durability and thermal stability your engine demands. Built with advanced heat-treatment and a specialized skirt coating,...09100941- SKU:
- 09100941
- Availability:
- Ships Same Business Day
- Weight:
- 0.42 LBS
- PISTON MATERIAL:
- CAST
- PRODUCT NAME:
- PISTON KIT
- ENGINE TYPE:
- 2-STROKE
- COMPRESSION RATIO IMPERIAL:
- STANDARD
- CYLINDER DIAMETER METRIC:
- 48.00 MM
- PISTON DIAMETER METRIC:
- 47.95 MM
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- DISPLACEMENT:
- 85 CC
- PISTON MATERIAL:
- ALUMINUM ALLOY
- SKIRT COATING:
- MOLYBDENUM DISULPHITE
- STYLE:
- CAST REPLICA
$127.95Qty in Cart: 0Quantity:Price:$127.95Subtotal: -
Wiseco Piston Honda CRF450R 2002-2008 338M07050
WISECO
$210.95When you're pushing a Honda CRF450R to its limits, your piston needs to handle extreme combustion pressures and sustained high RPMs without compromise. The Wiseco 338M07050 is precision-engineered to deliver reliable performance mile after mile, whether...338M07050- SKU:
- 338M07050
- Availability:
- Ships Same Business Day
- Weight:
- 0.80 LBS
- BORE - OVERSIZE:
- +0,50 MM
- ENGINE TYPE:
- 2-STROKE
- PISTON MATERIAL:
- 4032 ALUMINUM ALLOY
- RIDING STYLE:
- OFF-ROAD
- STROKE LENGTH METRIC:
- 64.40 MM
- UNITS:
- KIT
- PRODUCT NAME:
- PISTON KIT
- BORE - OVERSIZE METRIC:
- +0.50 MM
- DISPLACEMENT:
- 248 CC
- RIDING STYLE:
- UTV
- BORE SIZE METRIC:
- 70.50 MM
- MODEL:
- FORGED SERIES
- PISTON DIAMETER METRIC:
- 70.45 MM
- SKIRT COATING:
- NON-COATED
$210.95Qty in Cart: 0Quantity:Price:$210.95Subtotal: -
Wiseco Piston Kit Honda CR125M 1974-1978 1.0mm 339M05700
WISECO
$162.95If you're rebuilding a 1974-1978 Honda CR125M, a quality piston kit is non-negotiable—it directly impacts compression, power delivery, and engine longevity. Wiseco's 339M05700 delivers the precision and durability 2-stroke racers and serious hobbyists...339M05700- SKU:
- 339M05700
- Availability:
- Ships Same Business Day
- Weight:
- 0.40 LBS
- BORE SIZE METRIC:
- 57.00 MM
- PRODUCT NAME:
- PISTON KIT
- BORE - OVERSIZE METRIC:
- +1.00 MM
- DISPLACEMENT:
- 123 CC
- ENGINE TYPE:
- 2-STROKE
- PISTON DIAMETER METRIC:
- 56.94 MM
- RIDING STYLE:
- OFF-ROAD
- SKIRT COATING:
- NON-COATED
- UNITS:
- KIT
- MODEL:
- FORGED SERIES
- BORE - OVERSIZE:
- +1,00 MM
- PISTON MATERIAL:
- 4032 ALUMINUM ALLOY
- STROKE LENGTH METRIC:
- 50.00 MM
$162.95 -
VERTEX Piston Kit - High Compression 24116B
VERTEX
$296.95If you're building a high-compression engine that demands reliability under sustained load, the VERTEX Piston Kit 24116B delivers the precision and durability required for consistent power output. These pistons are engineered for forced induction and...09104118- SKU:
- 09104118
- Availability:
- Ships Same Business Day
- Weight:
- 0.60 LBS
- RIDING STYLE:
- OFF-ROAD
- STYLE:
- FORGED HIGH COMPRESSION
- UNITS:
- KIT
- CYLINDER DIAMETER METRIC:
- 88.00 MM
- ENGINE TYPE:
- 4-STROKE
- PISTON DIAMETER METRIC:
- 87.97 MM
- RIDING STYLE:
- STREET
- SKIRT COATING:
- MOLYBDENUM DISULPHITE
- COMPRESSION RATIO IMPERIAL:
- 15.1:1
- DISPLACEMENT:
- 350 CC
- PISTON MATERIAL:
- FORGED 2618 ALUMINUM
- PRODUCT NAME:
- PISTON KIT
$296.95Qty in Cart: 0Quantity:Price:$296.95Subtotal: -
VERTEX Piston Kit 24105B
VERTEX
$71.95A piston kit is the heart of your engine's combustion cycle, and the VERTEX Piston Kit 24105B is engineered to handle the demands of high-RPM racing and performance applications. The advanced heat-treatment process and low-friction skirt coating reduce...09104135- SKU:
- 09104135
- Availability:
- Ships Same Business Day
- Weight:
- 0.15 LBS
- CYLINDER DIAMETER METRIC:
- 39.00 MM
- PRODUCT NAME:
- PISTON KIT
- COMPRESSION RATIO IMPERIAL:
- STANDARD
- PISTON DIAMETER METRIC:
- 38.95 MM
- PISTON MATERIAL:
- ALUMINUM ALLOY
- PISTON MATERIAL:
- CAST
- SKIRT COATING:
- MOLYBDENUM DISULPHITE
- STYLE:
- CAST REPLICA
- DISPLACEMENT:
- 50 CC
- ENGINE TYPE:
- 2-STROKE
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
$71.95Qty in Cart: 0Quantity:Price:$71.95Subtotal: -
VERTEX Piston Kit - High Compression 23960B
VERTEX
$301.95Maximum compression means maximum power—the VERTEX Piston Kit 23960B delivers the elevated compression ratio you need to unlock additional horsepower and torque from your engine. Built with precision metallurgy and advanced surface treatments, these...09103403- SKU:
- 09103403
- Availability:
- Ships Same Business Day
- Weight:
- 0.91 LBS
- ENGINE TYPE:
- 4-STROKE
- PISTON DIAMETER METRIC:
- 96.95 MM
- PISTON MATERIAL:
- FORGED 2618 ALUMINUM
- SKIRT COATING:
- MOLYBDENUM DISULPHITE
- RIDING STYLE:
- OFF-ROAD
- CYLINDER DIAMETER METRIC:
- 97.00 MM
- COMPRESSION RATIO IMPERIAL:
- 13.7:1
- DISPLACEMENT:
- 450 CC
- PRODUCT NAME:
- PISTON KIT
- STYLE:
- FORGED HIGH COMPRESSION
- UNITS:
- KIT
$301.95 -
VERTEX Piston Kit 23961A
VERTEX
$235.95The VERTEX Piston Kit 23961A delivers the durability and precision your engine demands during sustained high-RPM operation. Built with advanced heat treatment and a specialized skirt coating, these pistons accelerate your break-in period while extending...09103405- SKU:
- 09103405
- Availability:
- Ships Same Business Day
- Weight:
- 0.56 LBS
$235.95Qty in Cart: 0Quantity:Price:$235.95Subtotal: -
VERTEX Piston Kit 24273A
VERTEX
$218.95The VERTEX Piston Kit 24273A delivers the durability and precision your engine demands, whether you're pushing peak RPMs on the track or rebuilding a tired top end. VERTEX's heat-treated, molybdenum-coated pistons reduce friction during break-in and...09105128- SKU:
- 09105128
- Availability:
- Ships Same Business Day
- Weight:
- 0.55 LBS
$218.95Qty in Cart: 0Quantity:Price:$218.95Subtotal: -
VERTEX Piston Kit 24273B
VERTEX
$242.95The VERTEX Piston Kit 24273B delivers the durability and precision engineering your engine demands, whether you're chasing lap times or maximizing street performance. Built with forged 2618 aluminum and treated through a rigorous T-5 heat cycle, these...09105129- SKU:
- 09105129
- Availability:
- Ships Same Business Day
- Weight:
- 0.55 LBS
$242.95Qty in Cart: 0Quantity:Price:$242.95Subtotal: -
VERTEX Piston Kit 24119B
VERTEX
$218.95The VERTEX Piston Kit 24119B delivers the durability and precision your engine demands under extreme conditions. With advanced heat treatment and specialized coatings designed to reduce friction during critical break-in phases, these pistons maintain...09104084- SKU:
- 09104084
- Availability:
- Ships Same Business Day
- Weight:
- 0.60 LBS
$218.95Qty in Cart: 0Quantity:Price:$218.95Subtotal: -
VERTEX Piston Kit - High Compression 24123C
VERTEX
$138.95The VERTEX Piston Kit 24123C delivers the compression ratio and durability your high-performance engine demands. Built with precision metallurgy and proven coatings, these pistons reduce break-in time while extending service life under sustained boost...09104102- SKU:
- 09104102
- Availability:
- Ships Same Business Day
- Weight:
- 0.60 LBS
- 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
- CYLINDER DIAMETER METRIC:
- 77.00 MM
- PISTON DIAMETER METRIC:
- 76.97 MM
- PISTON MATERIAL:
- FORGED 2618 ALUMINUM
- SKIRT COATING:
- MOLYBDENUM DISULPHITE
$138.95Qty in Cart: 0Quantity:Price:$138.95Subtotal:
