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 23599B
VERTEX
$271.95All pistons are heat-treated with a T-5 hardening and tempering cycle, All piston skirts are coated with a high-tech Molybdenum Disulphite coating for faster break-in time and increased piston life, Cast piston kits are gravity-cast aluminum alloy (not...09102566- SKU:
- 09102566
- Availability:
- Ships Same Business Day
- Weight:
- 0.54 LBS
- COMPRESSION RATIO IMPERIAL:
- 13.6:1
- PISTON MATERIAL:
- FORGED 2618 ALUMINUM
- SKIRT COATING:
- MOLYBDENUM DISULPHITE
- STYLE:
- FORGED REPLICA
- CYLINDER DIAMETER METRIC:
- 79.00 MM
- DISPLACEMENT:
- 250 CC
- ENGINE TYPE:
- 2-STROKE
- PRODUCT NAME:
- PISTON KIT
- PISTON DIAMETER METRIC:
- 78.96 MM
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
$271.95 -
VERTEX Piston Kit 23457B
VERTEX
$260.95All pistons are heat-treated with a T-5 hardening and tempering cycle, All piston skirts are coated with a high-tech Molybdenum Disulphite coating for faster break-in time and increased piston life, Cast piston kits are gravity-cast aluminum alloy (not...09102564- SKU:
- 09102564
- Availability:
- Ships Same Business Day
- Weight:
- 0.79 LBS
- PISTON MATERIAL:
- CAST
- PRODUCT NAME:
- PISTON KIT
- UNITS:
- KIT
- RIDING STYLE:
- STREET
- COMPRESSION RATIO IMPERIAL:
- STANDARD
- CYLINDER DIAMETER METRIC:
- 72.00 MM
- PISTON DIAMETER METRIC:
- 71.95 MM
- STYLE:
- CAST REPLICA
- DISPLACEMENT:
- 300 CC
- ENGINE TYPE:
- 2-STROKE
- PISTON MATERIAL:
- ALUMINUM ALLOY
- SKIRT COATING:
- MOLYBDENUM DISULPHITE
$260.95 -
ATHENA Piston Kit S4F100000190
ATHENA
$257.95Includes rings, clips and pin, Easy-to-follow step-by-step installation instructions09102535- SKU:
- 09102535
- Availability:
- Ships Same Business Day
- Weight:
- 0.93 LBS
- RIDING STYLE:
- OFF-ROAD
- STYLE:
- BIG BORE
- PISTON SIZE METRIC:
- STANDARD
- PRODUCT NAME:
- PISTON KIT
- COMPRESSION RATIO IMPERIAL:
- 12.0:1
- ENGINE TYPE:
- 4-STROKE
- PISTON DIAMETER METRIC:
- 100.00 MM
- UNITS:
- EACH
$257.95 -
ATHENA Piston Kit S4F04700001A
ATHENA
$142.95Two-stroke pistons are made from 4032 silicium, Four-stroke pistons are made from 2618 silicium - the same material used to produce Formula 1 pistons, Both include 3% copper in materials for better heat resistance, All pistons are forged using a...09102533- SKU:
- 09102533
- Availability:
- Ships Same Business Day
- Weight:
- 0.30 LBS
- COMPRESSION RATIO IMPERIAL:
- STOCK
- PRODUCT NAME:
- PISTON KIT
- UNITS:
- KIT
- DISPLACEMENT:
- 85 CC
- PISTON HEAD SHAPE:
- DOMED
- RIDING STYLE:
- OFF-ROAD
- BORE SIZE METRIC:
- 46.96 MM
- ENGINE TYPE:
- 2-STROKE
- PISTON MATERIAL:
- 4032 ALUMINUM ALLOY
- TYPE:
- A
$142.95 -
ATHENA Piston Kit S4F04500001B
ATHENA
$141.95Two-stroke pistons are made from 4032 silicium, Four-stroke pistons are made from 2618 silicium - the same material used to produce Formula 1 pistons, Both include 3% copper in materials for better heat resistance, All pistons are forged using a...09102532- SKU:
- 09102532
- Availability:
- Ships Same Business Day
- Weight:
- 0.30 LBS
- COMPRESSION RATIO IMPERIAL:
- STOCK
- PRODUCT NAME:
- PISTON KIT
- TYPE:
- B
- BORE SIZE METRIC:
- 44.97 MM
- PISTON HEAD SHAPE:
- DOMED
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- DISPLACEMENT:
- 65 CC
- ENGINE TYPE:
- 2-STROKE
- PISTON MATERIAL:
- 4032 ALUMINUM ALLOY
$141.95 -
ATHENA Piston Kit S4F04500001A
ATHENA
$142.95Two-stroke pistons are made from 4032 silicium, Four-stroke pistons are made from 2618 silicium - the same material used to produce Formula 1 pistons, Both include 3% copper in materials for better heat resistance, All pistons are forged using a...09102531- SKU:
- 09102531
- Availability:
- Ships Same Business Day
- Weight:
- 0.30 LBS
- COMPRESSION RATIO IMPERIAL:
- STOCK
- PRODUCT NAME:
- PISTON KIT
- BORE SIZE METRIC:
- 44.96 MM
- PISTON HEAD SHAPE:
- DOMED
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- DISPLACEMENT:
- 65 CC
- ENGINE TYPE:
- 2-STROKE
- PISTON MATERIAL:
- 4032 ALUMINUM ALLOY
- TYPE:
- A
$142.95 -
VERTEX Piston Kit 23378B
VERTEX
$271.95All pistons are heat treated with a T-5 hardening and tempering cycle, All piston skirts are coated with a high-tech Molybdenum Disulphite coating for faster break-in time and increased piston life, Cast piston kits are gravity cast aluminum alloy (not...09102099- SKU:
- 09102099
- Availability:
- Ships Same Business Day
- Weight:
- 1.07 LBS
- DISPLACEMENT:
- 450 CC
- PRODUCT NAME:
- PISTON KIT
- STYLE:
- FORGED HIGH COMPRESSION
- UNITS:
- KIT
- PISTON DIAMETER METRIC:
- 95.97 MM
- COMPRESSION RATIO IMPERIAL:
- 12.9:1
- CYLINDER DIAMETER METRIC:
- 96.00 MM
- ENGINE TYPE:
- 4-STROKE
- PISTON MATERIAL:
- FORGED 2618 ALUMINUM
- RIDING STYLE:
- OFF-ROAD
- SKIRT COATING:
- MOLYBDENUM DISULPHITE
$271.95 -
VERTEX Piston Kit 23198B
VERTEX
$268.95All pistons are heat treated with a T-5 hardening and tempering cycle, All piston skirts are coated with a high-tech Molybdenum Disulphite coating for faster break-in time and increased piston life, Cast piston kits are gravity cast aluminum alloy (not...09102091- SKU:
- 09102091
- Availability:
- Ships Same Business Day
- Weight:
- 0.90 LBS
$268.95 -
VERTEX Piston Kit - Standard 22521B
VERTEX
$218.95All pistons are heat-treated with a T-5 hardening and tempering cycle, All piston skirts are coated with a high-tech Molybdenum Disulphite coating for faster break-in time and increased piston life09101059- SKU:
- 09101059
- Availability:
- Ships Same Business Day
- Weight:
- 0.72 LBS
- ENGINE TYPE:
- 2-STROKE
- PISTON MATERIAL:
- ALUMINUM ALLOY
- RIDING STYLE:
- OFF-ROAD
- SKIRT COATING:
- MOLYBDENUM DISULPHITE
- STYLE:
- CAST REPLICA
- COMPRESSION RATIO IMPERIAL:
- STANDARD
- PISTON DIAMETER METRIC:
- 66.36 MM
- PISTON MATERIAL:
- CAST
- PRODUCT NAME:
- PISTON KIT
- UNITS:
- KIT
- CYLINDER DIAMETER METRIC:
- 66.40 MM
- DISPLACEMENT:
- 250 CC
$218.95 -
VERTEX Piston Kit - Standard 22712B
VERTEX
$146.95All pistons are heat-treated with a T-5 hardening and tempering cycle, All piston skirts are coated with a high-tech Molybdenum Disulphite coating for faster break-in time and increased piston life09101056- SKU:
- 09101056
- Availability:
- Ships Same Business Day
- Weight:
- 0.36 LBS
- COMPRESSION RATIO IMPERIAL:
- STANDARD
- PISTON MATERIAL:
- CAST
- PRODUCT NAME:
- PISTON KIT
- UNITS:
- KIT
- ENGINE TYPE:
- 2-STROKE
- PISTON MATERIAL:
- ALUMINUM ALLOY
- SKIRT COATING:
- MOLYBDENUM DISULPHITE
- CYLINDER DIAMETER METRIC:
- 54.00 MM
- PISTON DIAMETER METRIC:
- 53.96 MM
- RIDING STYLE:
- OFF-ROAD
- STYLE:
- CAST REPLICA
- DISPLACEMENT:
- 125 CC
$146.95 -
VERTEX Piston Kit - Standard 22498B
VERTEX
$163.95All pistons are heat-treated with a T-5 hardening and tempering cycle, All piston skirts are coated with a high-tech Molybdenum Disulphite coating for faster break-in time and increased piston life09101055- SKU:
- 09101055
- Availability:
- Ships Same Business Day
- Weight:
- 0.40 LBS
- COMPRESSION RATIO IMPERIAL:
- STANDARD
- PISTON MATERIAL:
- CAST
- PRODUCT NAME:
- PISTON KIT
- CYLINDER DIAMETER METRIC:
- 54.00 MM
- PISTON DIAMETER METRIC:
- 53.96 MM
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- DISPLACEMENT:
- 125 CC
- ENGINE TYPE:
- 2-STROKE
- PISTON MATERIAL:
- ALUMINUM ALLOY
- SKIRT COATING:
- MOLYBDENUM DISULPHITE
- STYLE:
- CAST RACE
$163.95 -
VERTEX Piston Kit - Standard 22248B
VERTEX
$141.95All pistons are heat-treated with a T-5 hardening and tempering cycle, All piston skirts are coated with a high-tech Molybdenum Disulphite coating for faster break-in time and increased piston life09101053- SKU:
- 09101053
- Availability:
- Ships Same Business Day
- Weight:
- 0.38 LBS
- CYLINDER DIAMETER METRIC:
- 54.00 MM
- PISTON DIAMETER METRIC:
- 53.96 MM
- PRODUCT NAME:
- PISTON KIT
- COMPRESSION RATIO IMPERIAL:
- STANDARD
- PISTON MATERIAL:
- CAST
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- DISPLACEMENT:
- 125 CC
- ENGINE TYPE:
- 2-STROKE
- PISTON MATERIAL:
- ALUMINUM ALLOY
- STYLE:
- CAST REPLICA
$141.95 -
VERTEX Piston Kit - Standard 22499B
VERTEX
$109.95All pistons are heat-treated with a T-5 hardening and tempering cycle, All piston skirts are coated with a high-tech Molybdenum Disulphite coating for faster break-in time and increased piston life09101023- SKU:
- 09101023
- Availability:
- Ships Same Business Day
- Weight:
- 0.28 LBS
- COMPRESSION RATIO IMPERIAL:
- STANDARD
- PISTON DIAMETER METRIC:
- 46.95 MM
- PISTON MATERIAL:
- CAST
- PRODUCT NAME:
- PISTON KIT
- CYLINDER DIAMETER METRIC:
- 47.00 MM
- DISPLACEMENT:
- 80 CC
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- ENGINE TYPE:
- 2-STROKE
- PISTON MATERIAL:
- ALUMINUM ALLOY
- SKIRT COATING:
- MOLYBDENUM DISULPHITE
- STYLE:
- CAST REPLICA
$109.95 -
VERTEX Piston Kit 23381B
VERTEX
$303.95All pistons are heat-treated with a T-5 hardening and tempering cycle, All piston skirts are coated with a high-tech Molybdenum Disulphite coating for faster break-in time and increased piston life09101020- SKU:
- 09101020
- Availability:
- Ships Same Business Day
- Weight:
- 0.92 LBS
$303.95 -
VERTEX Piston Kit 22942B
VERTEX
$303.95All pistons are heat-treated with a T-5 hardening and tempering cycle, All piston skirts are coated with a high-tech Molybdenum Disulphite coating for faster break-in time and increased piston life09101017- SKU:
- 09101017
- Availability:
- Ships Same Business Day
- Weight:
- 0.92 LBS
$303.95 -
VERTEX Piston Kit 23379B
VERTEX
$280.95All pistons are heat-treated with a T-5 hardening and tempering cycle, All piston skirts are coated with a high-tech Molybdenum Disulphite coating for faster break-in time and increased piston life09101012- SKU:
- 09101012
- Availability:
- Ships Same Business Day
- Weight:
- 0.90 LBS
$280.95 -
VERTEX Piston Kit 23235A
VERTEX
$280.95All pistons are heat-treated with a T-5 hardening and tempering cycle, All piston skirts are coated with a high-tech Molybdenum Disulphite coating for faster break-in time and increased piston life09101004- SKU:
- 09101004
- Availability:
- Ships Same Business Day
- Weight:
- 0.58 LBS
$280.95 -
VERTEX Piston Kit 22925B
VERTEX
$224.95All pistons are heat-treated with a T-5 hardening and tempering cycle, All piston skirts are coated with a high-tech Molybdenum Disulphite coating for faster break-in time and increased piston life09100992- SKU:
- 09100992
- Availability:
- Ships Same Business Day
- Weight:
- 0.61 LBS
- CYLINDER DIAMETER METRIC:
- 64.00 MM
- DISPLACEMENT:
- 200 CC
- PRODUCT NAME:
- PISTON KIT
- ENGINE TYPE:
- 2-STROKE
- PISTON DIAMETER METRIC:
- 63.95 MM
- PISTON MATERIAL:
- CAST
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- COMPRESSION RATIO IMPERIAL:
- STANDARD
- PISTON MATERIAL:
- ALUMINUM ALLOY
- SKIRT COATING:
- MOLYBDENUM DISULPHITE
- STYLE:
- CAST REPLICA
$224.95 -
ATHENA Piston Kit S5F08300005B
ATHENA
$256.95Two-stroke pistons are made from 4032 silicium, Four-stroke pistons are made from 2618 silicium - the same material used to produce Formula 1 pistons, Both include 3% copper in materials for better heat resistance, All pistons are forged using a...09100884- SKU:
- 09100884
- Availability:
- Ships Same Business Day
- Weight:
- 0.61 LBS
- PISTON MATERIAL:
- FORGED 2618 ALUMINUM
- DISPLACEMENT:
- 250 CC
- ENGINE TYPE:
- 4-STROKE
- PRODUCT NAME:
- PISTON KIT
- TYPE:
- B
- BORE SIZE METRIC:
- 82.96 MM
- COMPRESSION RATIO IMPERIAL:
- STOCK
- PISTON HEAD SHAPE:
- DOMED
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
$256.95 -
ATHENA Piston Kit S4C05800002B
ATHENA
$242.95Includes rings, clips and pin, Easy-to-follow step-by-step installation instructions09100878- SKU:
- 09100878
- Availability:
- Ships Same Business Day
- Weight:
- 0.43 LBS
- COMPRESSION RATIO IMPERIAL:
- 14.0:1
- ENGINE TYPE:
- 2-STROKE
- PISTON DIAMETER METRIC:
- 57.95 MM
- PISTON SIZE METRIC:
- STANDARD SIZE B
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- EACH
- STYLE:
- BIG BORE
- PRODUCT NAME:
- PISTON
$242.95
