Dirt Bike Engine
Dirt Bike Engine Parts at JJ Motorsports
Discover a full range of dirt bike engine components for rebuilding or upgrading your performance from JJ Motorsports. From crankshafts to cylinder heads and piston kits, these precision-engineered components ensure reliable performance. For additional upgrades, check out our full selection of off-road dirt bike parts to keep your engine running at peak efficiency on the track or trails.
Shop trusted brands like Wiseco for forged piston kits and K&N for high-flow oil filters. Explore related categories such as Dirt Bike Air and Fuel for intake upgrades or Dirt Bike Exhaust for complete systems.
Browse our in-stock inventory below with same-day shipping and expert support. Questions? Contact us for fitment advice!
- Product
- Qty in Cart
- Quantity
- Price
- Subtotal
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Wiseco 66mm 10.25:1 Piston Kit for 1992-2002 Honda XR200R PK1125
WISECO
$204.95Whether you're rebuilding a worn XR200R or restoring a dormant XL185S to peak performance, a quality piston kit is essential for reliable power delivery and engine longevity. The Wiseco PK1125...09030270- SKU:
- 09030270
- Availability:
- Ships Same Business Day
- Weight:
- 1.10 LBS
- ENGINE TYPE:
- 4-STROKE
- PISTON MATERIAL:
- 2618 ALUMINUM ALLOY
- STROKE LENGTH METRIC:
- 57.80 MM
- BORE - OVERSIZE METRIC:
- +0.50 MM
- BORE SIZE METRIC:
- 66.00 MM
- MODEL:
- FORGED SERIES
- PRODUCT NAME:
- REBUILD KIT
- TYPE:
- TOP END
- COMPRESSION RATIO IMPERIAL:
- 10.0:1
- DISPLACEMENT:
- 192 CC
- PISTON DIAMETER METRIC:
- 65.95 MM
- BORE - OVERSIZE:
- +0,50 MM
- RIDING STYLE:
- OFF-ROAD
- SKIRT COATING:
- NON-COATED
- UNITS:
- KIT
$204.95Qty in Cart: 0Quantity:Price:$204.95Subtotal: -
Wiseco Yamaha YZ85 2002-2018 Piston Kit with Gaskets PK1343
WISECO
$214.95When your YZ85's top-end starts losing compression or showing signs of wear, a quality piston kit is essential to restore engine performance and reliability. The Wiseco PK1343 delivers OEM-spec...09030271- SKU:
- 09030271
- Availability:
- Ships Same Business Day
- Weight:
- 0.75 LBS
- PISTON MATERIAL:
- ALUMINUM
- RIDING STYLE:
- OFF-ROAD
- STROKE LENGTH METRIC:
- 47.80 MM
- TYPE:
- TOP END
- BORE - OVERSIZE:
- STANDARD
- DISPLACEMENT:
- 103,5 CC
- MODEL:
- RACER'S CHOICE
- BORE - OVERSIZE METRIC:
- STANDARD
- BORE SIZE METRIC:
- 52.50 MM
- COOLING SYSTEM:
- LIQUID COOLED
- PISTON MATERIAL:
- FORGED
- PRODUCT NAME:
- REBUILD KIT
- UNITS:
- EACH
$214.95Qty in Cart: 0Quantity:Price:$214.95Subtotal: -
Wiseco Piston Kit with Gaskets 40mm Bore for Yamaha PW50 1981-2025 PK1157
WISECO
$171.95A worn or damaged piston directly throttles your PW50's performance, causing compression loss, poor throttle response, and accelerated engine wear. The Wiseco PK1157 restores full compression...09030275- SKU:
- 09030275
- Availability:
- Ships Same Business Day
- Weight:
- 0.65 LBS
- BORE SIZE METRIC:
- 40.00 MM
- PRODUCT NAME:
- REBUILD KIT
- TYPE:
- TOP END
- COOLING SYSTEM:
- AIR COOLED
- DISPLACEMENT:
- 49 CC
- PISTON MATERIAL:
- ALUMINUM
- PISTON MATERIAL:
- FORGED
- RIDING STYLE:
- OFF-ROAD
- STROKE LENGTH METRIC:
- 39.20 MM
- UNITS:
- EACH
- BORE - OVERSIZE:
- STANDARD
- BORE - OVERSIZE METRIC:
- STANDARD
- MODEL:
- RACER'S CHOICE
$171.95 -
Wiseco Yamaha YZ125 2003-2004 Piston Kit with Gaskets PK1344
WISECO
$224.95Your YZ125's piston is the heart of engine performance—worn or undersized pistons rob you of power, throttle response, and reliability. The Wiseco PK1344 Pro-Lite Kit restores that performance with...09030283- SKU:
- 09030283
- Availability:
- Ships Same Business Day
- Weight:
- 0.90 LBS
- PISTON DIAMETER METRIC:
- 53.95 MM
- SKIRT COATING:
- NON-COATED
- STROKE LENGTH METRIC:
- 54.50 MM
- BORE - OVERSIZE METRIC:
- STANDARD
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- BORE SIZE METRIC:
- 54.00 MM
- DISPLACEMENT:
- 125 CC
- MODEL:
- PRO-LITE
- PRODUCT NAME:
- REBUILD KIT
- TYPE:
- TOP END
- BORE - OVERSIZE:
- STANDARD
- ENGINE TYPE:
- 2-STROKE
- PISTON MATERIAL:
- 4032 ALUMINUM ALLOY
$224.95 -
Wiseco Piston Kit for Honda CR80R 1993-2002 PK1185
WISECO
$214.95The CR80R demands a piston kit that can handle high RPM abuse while maintaining bore integrity—the Wiseco PK1185 delivers exactly that. This CNC-machined, aerospace-grade aluminum piston assembly...09030285- SKU:
- 09030285
- Availability:
- Ships Same Business Day
- Weight:
- 0.85 LBS
- BORE - OVERSIZE METRIC:
- +5.00 MM
- COOLING SYSTEM:
- LIQUID COOLED
- UNITS:
- EACH
- BORE SIZE METRIC:
- 52.00 MM
- MODEL:
- RACER'S CHOICE
- PRODUCT NAME:
- REBUILD KIT
- TYPE:
- TOP END
- BORE - OVERSIZE:
- +5,00 MM
- PISTON MATERIAL:
- FORGED
- RIDING STYLE:
- OFF-ROAD
- STROKE LENGTH METRIC:
- 47.80 MM
- DISPLACEMENT:
- 101,5 CC
- PISTON MATERIAL:
- ALUMINUM
$214.95Qty in Cart: 0Quantity:Price:$214.95Subtotal: -
Wiseco 54mm Piston Kit with Gaskets for 2003 Honda CR125R PK1265
WISECO
$243.95A worn or damaged piston directly compromises your CR125R's compression, throttle response, and fuel efficiency. This complete Wiseco kit eliminates guesswork with OEM-spec fitment and quality...09030286- SKU:
- 09030286
- Availability:
- Ships Same Business Day
- Weight:
- 0.90 LBS
- BORE - OVERSIZE:
- STANDARD
- BORE - OVERSIZE METRIC:
- STANDARD
- ENGINE TYPE:
- 2-STROKE
- PISTON MATERIAL:
- 4032 ALUMINUM ALLOY
- RIDING STYLE:
- OFF-ROAD
- STROKE LENGTH METRIC:
- 54.50 MM
- UNITS:
- KIT
- BORE SIZE METRIC:
- 54.00 MM
- DISPLACEMENT:
- 125 CC
- MODEL:
- PRO-LITE
- PRODUCT NAME:
- REBUILD KIT
- TYPE:
- TOP END
- PISTON DIAMETER METRIC:
- 53.95 MM
- SKIRT COATING:
- NON-COATED
$243.95 -
Wiseco Piston Kit with Gaskets for 1993-1998 Suzuki RMX250 PK1339
WISECO
$277.95A worn or damaged piston directly compromises combustion efficiency, throttle response, and overall engine reliability—especially critical on a 2-stroke like the RMX250 where every combustion cycle...09030287- SKU:
- 09030287
- Availability:
- Ships Same Business Day
- Weight:
- 1.50 LBS
- BORE - OVERSIZE METRIC:
- STANDARD
- PISTON DIAMETER METRIC:
- 66.94 MM
- PRODUCT NAME:
- REBUILD KIT
- BORE - OVERSIZE:
- STANDARD
- DISPLACEMENT:
- 246 CC
- ENGINE TYPE:
- 2-STROKE
- SKIRT COATING:
- NON-COATED
- STROKE LENGTH METRIC:
- 70.80 MM
- PISTON MATERIAL:
- 4032 ALUMINUM ALLOY
- BORE SIZE METRIC:
- 67.00 MM
- MODEL:
- PRO-LITE
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- TOP END
- UNITS:
- KIT
$277.95Qty in Cart: 0Quantity:Price:$277.95Subtotal: -
Wiseco Yamaha YZ125 2001 54mm Piston Kit PK1348
WISECO
$225.95If you're running a 2001 YZ125 and want to maximize power output without sacrificing reliability, a quality piston kit is non-negotiable. The Wiseco PK1348 delivers the precision engineering and...09030288- SKU:
- 09030288
- Availability:
- Ships Same Business Day
- Weight:
- 0.55 LBS
- BORE - OVERSIZE METRIC:
- STANDARD
- PISTON MATERIAL:
- 4032 ALUMINUM ALLOY
- DISPLACEMENT:
- 124 CC
- STROKE LENGTH METRIC:
- 54.50 MM
- BORE - OVERSIZE:
- STANDARD
- BORE SIZE METRIC:
- 54.00 MM
- ENGINE TYPE:
- 2-STROKE
- PRODUCT NAME:
- REBUILD KIT
- TYPE:
- TOP END
- MODEL:
- PRO-LITE
- PISTON DIAMETER METRIC:
- 53.95 MM
- RIDING STYLE:
- OFF-ROAD
- SKIRT COATING:
- NON-COATED
- UNITS:
- KIT
$225.95 -
Wiseco Piston Kit for Honda CR250R 1992-1996 PK1128
WISECO
$259.95If you're running a CR250R from the early '90s, piston wear directly impacts your engine's ability to hold compression and deliver peak power. The Wiseco PK1128 restores that lost performance through...09030292- SKU:
- 09030292
- Availability:
- Ships Same Business Day
- Weight:
- 1.35 LBS
- BORE - OVERSIZE:
- STANDARD
- BORE - OVERSIZE METRIC:
- STANDARD
- ENGINE TYPE:
- 2-STROKE
- PISTON MATERIAL:
- 4032 ALUMINUM ALLOY
- BORE SIZE METRIC:
- 66.40 MM
- PISTON DIAMETER METRIC:
- 66.36 MM
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- DISPLACEMENT:
- 249 CC
- MODEL:
- PRO-LITE
- PRODUCT NAME:
- REBUILD KIT
- TYPE:
- TOP END
- SKIRT COATING:
- NON-COATED
- STROKE LENGTH METRIC:
- 72.00 MM
$259.95Qty in Cart: 0Quantity:Price:$259.95Subtotal: -
Wiseco Piston Honda CRF450R 2002 431M07000
WISECO
$199.95If you're rebuilding a Honda CRF450R engine or refreshing a high-mileage top end, a quality OEM-equivalent piston is non-negotiable—it's the foundation of reliable horsepower and longevity. The...431M07000- SKU:
- 431M07000
- Availability:
- Ships Same Business Day
- Weight:
- 0.40 LBS
- PISTON DIAMETER METRIC:
- 69.95 MM
- PISTON MATERIAL:
- 4032 ALUMINUM ALLOY
- RIDING STYLE:
- OFF-ROAD
- DISPLACEMENT:
- 248 CC
- ENGINE TYPE:
- 2-STROKE
- SKIRT COATING:
- NON-COATED
- STROKE LENGTH METRIC:
- 64.40 MM
- BORE - OVERSIZE:
- STANDARD
- BORE - OVERSIZE METRIC:
- STANDARD
- BORE SIZE METRIC:
- 70.00 MM
- MODEL:
- FORGED SERIES
- PRODUCT NAME:
- PISTON KIT
- UNITS:
- KIT
$199.95Qty in Cart: 0Quantity:Price:$199.95Subtotal: -
Wiseco Piston Honda CRF450R 2002-2008 431M07050
WISECO
$221.95If you're running a Honda CRF450R from the 2002-2008 generation, a worn or damaged piston directly impacts combustion efficiency, throttle response, and overall engine reliability. The Wiseco...431M07050- SKU:
- 431M07050
- Availability:
- Ships Same Business Day
- Weight:
- 0.50 LBS
- BORE - OVERSIZE METRIC:
- +0.50 MM
- ENGINE TYPE:
- 2-STROKE
- PRODUCT NAME:
- PISTON KIT
- STROKE LENGTH METRIC:
- 64.40 MM
- PISTON MATERIAL:
- 4032 ALUMINUM ALLOY
- BORE - OVERSIZE:
- +0,50 MM
- DISPLACEMENT:
- 248 CC
- RIDING STYLE:
- OFF-ROAD
- SKIRT COATING:
- NON-COATED
- BORE SIZE METRIC:
- 70.50 MM
- MODEL:
- FORGED SERIES
- PISTON DIAMETER METRIC:
- 70.45 MM
- UNITS:
- KIT
$221.95Qty in Cart: 0Quantity:Price:$221.95Subtotal: -
Wiseco Piston Kit 71mm Oversize for Honda CR250R 1978-1980 431M07100
WISECO
$221.95If you're running a Honda CR250R with high mileage or planning a performance build, a quality piston kit is essential to restore compression and unlock the engine's full potential. Wiseco's forged...431M07100- SKU:
- 431M07100
- Availability:
- Ships Same Business Day
- Weight:
- 0.55 LBS
- MODEL:
- FORGED SERIES
- SKIRT COATING:
- NON-COATED
- DISPLACEMENT:
- 248 CC
- ENGINE TYPE:
- 2-STROKE
- PISTON DIAMETER METRIC:
- 70.95 MM
- PISTON MATERIAL:
- 4032 ALUMINUM ALLOY
- RIDING STYLE:
- OFF-ROAD
- STROKE LENGTH METRIC:
- 64.40 MM
- BORE - OVERSIZE:
- +1,00 MM
- BORE - OVERSIZE METRIC:
- +1.00 MM
- BORE SIZE METRIC:
- 71.00 MM
- PRODUCT NAME:
- PISTON KIT
- UNITS:
- KIT
$221.95Qty in Cart: 0Quantity:Price:$221.95Subtotal: -
Wiseco Piston Kit 72mm Oversize for Honda CR250R 1978-1980 431M07200
WISECO
$232.95If you're rebuilding a CR250R or ATC250R engine, piston quality directly impacts reliability and power delivery. Wiseco's high-silicon aluminum construction handles the extreme combustion pressures...431M07200- SKU:
- 431M07200
- Availability:
- Ships Same Business Day
- Weight:
- 0.80 LBS
- DISPLACEMENT:
- 248 CC
- PISTON DIAMETER METRIC:
- 71.95 MM
- SKIRT COATING:
- NON-COATED
- MODEL:
- FORGED SERIES
- PRODUCT NAME:
- PISTON KIT
- UNITS:
- KIT
- BORE - OVERSIZE METRIC:
- +2.00 MM
- BORE SIZE METRIC:
- 72.00 MM
- STROKE LENGTH METRIC:
- 64.40 MM
- BORE - OVERSIZE:
- +2,00 MM
- ENGINE TYPE:
- 2-STROKE
- PISTON MATERIAL:
- 4032 ALUMINUM ALLOY
- RIDING STYLE:
- OFF-ROAD
$232.95Qty in Cart: 0Quantity:Price:$232.95Subtotal: -
Wiseco 85mm Piston Kit for 1983-1984 Honda XR350R 4286M08500
WISECO
$184.95If you're running a 1983-1984 Honda XR350R, piston wear directly impacts power delivery, fuel efficiency, and engine reliability. The Wiseco 85mm Piston Kit restores lost performance and allows you...4286M08500- SKU:
- 4286M08500
- Availability:
- Ships Same Business Day
- Weight:
- 1.00 LBS
- DISPLACEMENT:
- 339 CC
- PISTON MATERIAL:
- FORGED 2618 ALUMINUM
- PRODUCT NAME:
- PISTON KIT
- STROKE LENGTH METRIC:
- 61.30 MM
- BORE SIZE METRIC:
- 85.00 MM
- ENGINE TYPE:
- 4-STROKE
- BORE - OVERSIZE:
- +1,00 MM
- BORE - OVERSIZE METRIC:
- +1.00 MM
- COMPRESSION RATIO IMPERIAL:
- 10.0:1
- PISTON DIAMETER METRIC:
- 84.95 MM
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- MODEL:
- FORGED SERIES
- SKIRT COATING:
- NON-COATED
$184.95Qty in Cart: 0Quantity:Price:$184.95Subtotal: -
Wiseco Piston Kit Standard 86mm Kawasaki KX 500 1988-2004 575M08600
WISECO
$243.95The Wiseco 86mm piston kit is engineered for the KX500 to deliver measurable gains in throttle response and combustion efficiency. If you're running stock pistons, you're leaving horsepower on the...575M08600- SKU:
- 575M08600
- Availability:
- Ships Same Business Day
- Weight:
- 1.05 LBS
- BORE - OVERSIZE:
- STANDARD
- BORE - OVERSIZE METRIC:
- STANDARD
- PISTON MATERIAL:
- ALUMINUM ALLOY
- RIDING STYLE:
- OFF-ROAD
- STROKE LENGTH METRIC:
- 86.00 MM
- UNITS:
- EACH
- BORE SIZE METRIC:
- 86.00 MM
- PISTON MATERIAL:
- FORGED
- PRODUCT NAME:
- PISTON
- STROKE LENGTH:
- 86,00 MM
- DISPLACEMENT:
- 499 CC
$243.95Qty in Cart: 0Quantity:Price:$243.95Subtotal: -
Wiseco Piston Kit 1988-2004 Kawasaki KX 500 575M08650
WISECO
$234.95If you're running a KX500 at the limit—whether on the track or the trail—piston wear and loss of compression will eventually compromise your power. The Wiseco Piston Kit restores full performance...575M08650- SKU:
- 575M08650
- Availability:
- Ships Same Business Day
- Weight:
- 1.10 LBS
- BORE SIZE METRIC:
- 86.50 MM
- DISPLACEMENT:
- 499 CC
- PISTON MATERIAL:
- FORGED
- PRODUCT NAME:
- PISTON
- STROKE LENGTH:
- 86,00 MM
- PISTON MATERIAL:
- ALUMINUM ALLOY
- STROKE LENGTH METRIC:
- 86.00 MM
- UNITS:
- EACH
- RIDING STYLE:
- OFF-ROAD
- BORE - OVERSIZE:
- +0,50 MM
- BORE - OVERSIZE METRIC:
- +0.50 MM
$234.95Qty in Cart: 0Quantity:Price:$234.95Subtotal: -
Wiseco Piston Kit 1988-2004 Kawasaki KX 500 575M08700
WISECO
$234.95If you're rebuilding a KX500 or pushing your machine harder on the track, piston quality directly impacts power delivery, reliability, and how long your engine lasts between rebuilds. The Wiseco...575M08700- SKU:
- 575M08700
- Availability:
- Ships Same Business Day
- Weight:
- 1.10 LBS
- BORE - OVERSIZE:
- +1,00 MM
- DISPLACEMENT:
- 499 CC
- PRODUCT NAME:
- PISTON
- BORE - OVERSIZE METRIC:
- +1.00 MM
- PISTON MATERIAL:
- ALUMINUM ALLOY
- PISTON MATERIAL:
- FORGED
- STROKE LENGTH METRIC:
- 86.00 MM
- UNITS:
- EACH
- STROKE LENGTH:
- 86,00 MM
- BORE SIZE METRIC:
- 87.00 MM
- RIDING STYLE:
- OFF-ROAD
$234.95Qty in Cart: 0Quantity:Price:$234.95Subtotal: -
Wiseco Piston Standard Yamaha YTZ250 Tri-Z 1985 515M06800
WISECO
$204.95A worn or damaged piston compromises engine efficiency, throttle response, and overall reliability—especially critical for serious riders pushing their YTZ 250 Tri-Z to its limits. The Wiseco piston...515M06800- SKU:
- 515M06800
- Availability:
- Ships Same Business Day
- Weight:
- 0.80 LBS
- DISPLACEMENT:
- 246,8 CC
- BORE - OVERSIZE:
- STANDARD
- BORE - OVERSIZE METRIC:
- STANDARD
- BORE SIZE METRIC:
- 68.00 MM
- PISTON MATERIAL:
- ALUMINUM ALLOY
- PRODUCT NAME:
- PISTON
- RIDING STYLE:
- OFF-ROAD
- STROKE LENGTH:
- 68,00 MM
- UNITS:
- EACH
- STROKE LENGTH METRIC:
- 68.00 MM
- PISTON MATERIAL:
- FORGED
$204.95Qty in Cart: 0Quantity:Price:$204.95Subtotal: -
Wiseco Piston Kit Yamaha IT 250 1983 515M06900
WISECO
$223.95A worn or damaged piston directly compromises engine compression, throttle response, and overall reliability—especially critical in a two-stroke where the piston cycles thousands of times per minute...515M06900- SKU:
- 515M06900
- Availability:
- Ships Same Business Day
- Weight:
- 0.80 LBS
- BORE - OVERSIZE:
- +1,00 MM
- PISTON MATERIAL:
- FORGED
- STROKE LENGTH METRIC:
- 68.00 MM
- DISPLACEMENT:
- 246,8 CC
- BORE - OVERSIZE METRIC:
- +1.00 MM
- BORE SIZE METRIC:
- 69.00 MM
- PRODUCT NAME:
- PISTON
- RIDING STYLE:
- OFF-ROAD
- PISTON MATERIAL:
- ALUMINUM ALLOY
- STROKE LENGTH:
- 68,00 MM
- UNITS:
- EACH
$223.95Qty in Cart: 0Quantity:Price:$223.95Subtotal: -
Wiseco Piston Standard Kawasaki KX 80 1984-1985 514M04800
WISECO
$141.95A piston is the engine's hardest-working component—when it fails, your bike is done. The Wiseco Piston for Kawasaki KX80 (1984-1985) delivers the durability and power output you need to push your...514M04800- SKU:
- 514M04800
- Availability:
- Ships Same Business Day
- Weight:
- 0.25 LBS
- BORE SIZE METRIC:
- 48.00 MM
- DISPLACEMENT:
- 82 CC
- STROKE LENGTH:
- 45,80 MM
- BORE - OVERSIZE METRIC:
- STANDARD
- PISTON MATERIAL:
- FORGED
- PRODUCT NAME:
- PISTON
- BORE - OVERSIZE:
- STANDARD
- PISTON MATERIAL:
- ALUMINUM ALLOY
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- EACH
- STROKE LENGTH METRIC:
- 45.80 MM
$141.95Qty in Cart: 0Quantity:Price:$141.95Subtotal:
