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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On Sale
ATHENA Piston Kit S4F04500001A
ATHENA
MSRP: $142.95Now: $129.00Was: $142.95Maximum piston longevity and reliability demand materials engineered for extreme thermal stress—and the ATHENA S4F04500001A delivers exactly that. Whether you're running a two-stroke or four-stroke, this kit uses the same aerospace-grade aluminum alloys...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
MSRP: $142.95Now: $129.00Was: $142.95 -
VERTEX Piston Kit 23378B
VERTEX
$271.95Whether you're rebuilding a tired engine or upgrading to higher compression, the VERTEX Piston Kit 23378B delivers the durability and precision needed for sustained high-RPM performance. The combination of advanced heat treatment, molybdenum-coated...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
$289.95The VERTEX Piston Kit 23198B delivers the durability and precision needed for high-rpm engine demands, whether you're rebuilding after wear or upgrading for peak performance. Built with heat-treated aluminum and a molybdenum disulfide coating, these...09102091- SKU:
- 09102091
- Availability:
- Ships Same Business Day
- Weight:
- 0.90 LBS
$289.95 -
VERTEX Piston Kit - Standard 22521B
VERTEX
$235.95A quality piston kit is the foundation of any reliable engine build—especially when you're pushing performance limits. The VERTEX Piston Kit 22521B delivers the durability and precision you need for consistent power delivery across extended racing...09101059- 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
$235.95Qty in Cart: 0Quantity:Price:$235.95Subtotal: -
VERTEX Piston Kit - Standard 22712B
VERTEX
$158.95The VERTEX Piston Kit 22712B delivers the durability and precision your engine demands, whether you're building a street machine or prepping for the track. Heat-treated to withstand extreme combustion pressures and temperatures, these pistons feature a...09101056- 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
$158.95 -
VERTEX Piston Kit - Standard 22498B
VERTEX
$176.95Quality pistons are the foundation of reliable engine performance, especially if you're pushing your build to higher RPMs or boost levels. The VERTEX Piston Kit 22498B delivers the durability and precision you need for consistent power delivery without...09101055- 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
$176.95Qty in Cart: 0Quantity:Price:$176.95Subtotal: -
VERTEX Piston Kit - Standard 22248B
VERTEX
$141.95A quality piston kit is the foundation of reliable engine performance, especially under high RPM and boost conditions. The VERTEX Piston Kit 22248B combines precision engineering with proven durability features that reduce wear during critical break-in...09101053- 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
$141.95Qty in Cart: 0Quantity:Price:$141.95Subtotal: -
VERTEX Piston Kit - Standard 22499B
VERTEX
$118.95A quality piston kit is the foundation of reliable engine performance, and the VERTEX Standard 22499B delivers the durability and precision required for both street and track applications. The advanced T-5 heat treatment and molybdenum disulfide coating...09101023- 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
$118.95 -
VERTEX Piston Kit 23381B
VERTEX
$327.95The VERTEX Piston Kit 23381B delivers the durability and precision required for sustained high-RPM performance and reliability across demanding racing and modified engine applications. With factory-grade heat treatment and a specialized piston skirt...09101020- SKU:
- 09101020
- Availability:
- Ships Same Business Day
- Weight:
- 0.92 LBS
$327.95Qty in Cart: 0Quantity:Price:$327.95Subtotal: -
VERTEX Piston Kit 22942B
VERTEX
$327.95If you're building a high-revving engine or pushing your existing platform to the next level, piston quality directly impacts reliability and longevity under sustained load. The VERTEX Piston Kit 22942B delivers OEM-grade durability with purpose-built...09101017- SKU:
- 09101017
- Availability:
- Ships Same Business Day
- Weight:
- 0.92 LBS
$327.95Qty in Cart: 0Quantity:Price:$327.95Subtotal: -
VERTEX Piston Kit 23379B
VERTEX
$302.95High-revving engines demand pistons engineered for sustained performance under extreme conditions. The VERTEX Piston Kit 23379B combines advanced metallurgy with precision surface coatings to deliver reliable power delivery and extended component life...09101012- SKU:
- 09101012
- Availability:
- Ships Same Business Day
- Weight:
- 0.90 LBS
$302.95 -
VERTEX Piston Kit 23235A
VERTEX
$302.95A quality piston kit is foundational to engine reliability and performance—especially if you're running higher boost levels or extended track sessions. The VERTEX Piston Kit 23235A delivers the durability and precision fit that serious racers and...09101004- SKU:
- 09101004
- Availability:
- Ships Same Business Day
- Weight:
- 0.58 LBS
$302.95Qty in Cart: 0Quantity:Price:$302.95Subtotal: -
VERTEX Piston Kit 22925B
VERTEX
$242.95Piston failure is one of the most costly engine catastrophes—and the VERTEX Piston Kit 22925B eliminates the guesswork with OEM-quality construction and race-proven durability. The combination of precision heat treatment and low-friction coating means...09100992- 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
$242.95 -
On Sale
ATHENA Piston Kit S5F08300005B
ATHENA
MSRP: $256.95Now: $231.00Was: $256.95Whether you're rebuilding a high-revving two-stroke or fortifying a four-stroke engine, piston quality directly impacts power delivery, longevity, and reliability under extreme conditions. The ATHENA Piston Kit S5F08300005B delivers the precision and...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
MSRP: $256.95Now: $231.00Was: $256.95 -
On Sale
ATHENA Piston Kit S4C05800002B
ATHENA
MSRP: $242.95Now: $219.00Was: $242.95A high-performance piston kit is essential for engines pushing beyond stock limits—whether you're building a race engine or restoring a worn block. The ATHENA S4C05800002B delivers OEM-equivalent quality with precision-engineered components that ensure...09100878- 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
MSRP: $242.95Now: $219.00Was: $242.95Qty in Cart: 0Quantity:Price:MSRP: $242.95Now: $219.00Was: $242.95Subtotal: -
On Sale
ATHENA Piston Kit S4C05800002A
ATHENA
MSRP: $242.95Now: $219.00Was: $242.95A quality piston kit is the foundation of reliable engine performance, whether you're rebuilding for increased displacement or restoring original specs. The ATHENA S4C05800002A delivers precision-engineered pistons with matched rings, clips, and...09100877- SKU:
- 09100877
- Availability:
- Ships Same Business Day
- Weight:
- 0.43 LBS
- COMPRESSION RATIO IMPERIAL:
- 14.0:1
- ENGINE TYPE:
- 2-STROKE
- PISTON SIZE METRIC:
- STANDARD SIZE A
- RIDING STYLE:
- OFF-ROAD
- PISTON DIAMETER METRIC:
- 57.94 MM
- STYLE:
- BIG BORE
- UNITS:
- EACH
- PRODUCT NAME:
- PISTON
MSRP: $242.95Now: $219.00Was: $242.95Qty in Cart: 0Quantity:Price:MSRP: $242.95Now: $219.00Was: $242.95Subtotal: -
Wiseco Piston Kit Standard 66mm 12.2:1 Honda CRF150R 2007-2009 4924M06600
WISECO
$239.95Stock pistons wear out, especially in high-RPM racing environments—Wiseco's forged aluminum construction and moly-coated skirts deliver the durability and heat resistance you need for consistent performance lap after lap. The 12.2:1 compression ratio...09100821- SKU:
- 09100821
- Availability:
- Ships Same Business Day
- Weight:
- 0.40 LBS
- PISTON MATERIAL:
- FORGED
- STROKE LENGTH METRIC:
- 43.70 MM
- BORE - OVERSIZE:
- STANDARD
- BORE - OVERSIZE METRIC:
- STANDARD
- PRODUCT NAME:
- PISTON
- SKIRT COATING:
- MOLY COATED
- BORE SIZE METRIC:
- 66.00 MM
- COMPRESSION RATIO IMPERIAL:
- 12.2:1
- DISPLACEMENT:
- 150 CC
- ENGINE TYPE:
- 4-STROKE
- PISTON MATERIAL:
- ALUMINUM ALLOY
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- EACH
$239.95Qty in Cart: 0Quantity:Price:$239.95Subtotal: -
Wiseco Piston Kit Standard Bore 66mm 11.7:1 Compression Honda CRF150R 2007-2009 4915M06600
WISECO
$199.95When your CRF150R's OEM piston reaches its limit, a quality rebuild is the difference between a sluggish engine and one that delivers crisp throttle response and reliable power. The Wiseco 4915M06600 replaces worn internals with precision-engineered...09100819- SKU:
- 09100819
- Availability:
- Ships Same Business Day
- Weight:
- 0.39 LBS
- STROKE LENGTH METRIC:
- 43.70 MM
- COMPRESSION RATIO IMPERIAL:
- 11.7:1
- SKIRT COATING:
- MOLY COATED
- BORE - OVERSIZE METRIC:
- STANDARD
- PISTON MATERIAL:
- FORGED
- PRODUCT NAME:
- PISTON
- RIDING STYLE:
- OFF-ROAD
- BORE - OVERSIZE:
- STANDARD
- BORE SIZE METRIC:
- 66.00 MM
- DISPLACEMENT:
- 150 CC
- ENGINE TYPE:
- 4-STROKE
- PISTON MATERIAL:
- ALUMINUM ALLOY
- UNITS:
- EACH
$199.95Qty in Cart: 0Quantity:Price:$199.95Subtotal: -
On Sale
ATHENA Piston Kit S5F08300002B
ATHENA
MSRP: $245.95Now: $221.00Was: $245.95A piston kit is the heart of any rebuild—getting the right one ensures reliable compression, proper ring sealing, and consistent power delivery across your entire RPM range. The ATHENA Piston Kit S5F08300002B delivers OEM-quality construction with...09100727- SKU:
- 09100727
- Availability:
- Ships Same Business Day
- Weight:
- 0.65 LBS
- COMPRESSION RATIO IMPERIAL:
- 12.5:1
- ENGINE TYPE:
- 4-STROKE
- PISTON DIAMETER METRIC:
- 82.96 MM
- PISTON SIZE METRIC:
- STANDARD SIZE B
- UNITS:
- EACH
- RIDING STYLE:
- OFF-ROAD
- STYLE:
- BIG BORE
- PRODUCT NAME:
- PISTON
MSRP: $245.95Now: $221.00Was: $245.95Qty in Cart: 0Quantity:Price:MSRP: $245.95Now: $221.00Was: $245.95Subtotal: -
On Sale
ATHENA Piston Kit S4F10000007A
ATHENA
MSRP: $240.95Now: $217.00Was: $240.95A precision piston kit is fundamental to engine reliability and performance—poor quality pistons lead to blow-by, reduced compression, and catastrophic failure under load. The ATHENA S4F10000007A delivers OEM-equivalent dimensional accuracy and material...09100255- SKU:
- 09100255
- Availability:
- Ships Same Business Day
- Weight:
- 0.95 LBS
- COMPRESSION RATIO IMPERIAL:
- 11.6:1
- PISTON SIZE METRIC:
- STANDARD SIZE A
- PISTON DIAMETER METRIC:
- 99.95 MM
- RIDING STYLE:
- ATV
- PRODUCT NAME:
- PISTON
- RIDING STYLE:
- OFF-ROAD
- STYLE:
- BIG BORE
- ENGINE TYPE:
- 4-STROKE
- UNITS:
- EACH
MSRP: $240.95Now: $217.00Was: $240.95Qty in Cart: 0Quantity:Price:MSRP: $240.95Now: $217.00Was: $240.95Subtotal:
