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!
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- Qty in Cart
- Quantity
- Price
- Subtotal
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On Sale
Wiseco YZ490 1982-1983 IT490 1983-1984 Piston Kit 478M08750
WISECO
MSRP: $234.95Now: $200.00Was: $234.95Engineered for superior performance, the Wiseco Piston 478M08750 is crafted from a high-silicon alloy, ensuring exceptional strength and reliability. Ideal for both trail and racing enthusiasts, this piston is designed to enhance your engine's efficiency...478M08750- SKU:
- 478M08750
- Availability:
- Ships Same Business Day
- Weight:
- 1.15 LBS
- BORE - OVERSIZE METRIC:
- +0.50 MM
- BORE SIZE METRIC:
- 87.50 MM
- PRODUCT NAME:
- PISTON KIT
- STROKE LENGTH METRIC:
- 82.00 MM
- BORE - OVERSIZE:
- +0,50 MM
- DISPLACEMENT:
- 487 CC
- ENGINE TYPE:
- 2-STROKE
- PISTON MATERIAL:
- 4032 ALUMINUM ALLOY
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- MODEL:
- FORGED SERIES
- PISTON DIAMETER METRIC:
- 87.42 MM
- SKIRT COATING:
- NON-COATED
MSRP: $234.95Now: $200.00Was: $234.95Qty in Cart: 0Quantity:Price:MSRP: $234.95Now: $200.00Was: $234.95Subtotal: -
Wossner Connecting Rod Yamaha YZ250F 2014-2025 P4072
WOSSNER
$174.00Experience unparalleled performance and durability with the WOSSNER Connecting Rod Kit for the YZ250F. This meticulously engineered kit ensures a seamless fit with OEM components, providing a reliable solution for crankshaft rebuilds. Crafted from...09230562- SKU:
- 09230562
- Availability:
- Ships Same Business Day
- Weight:
- 1.25 LBS
- STYLE:
- STANDARD
- UNITS:
- KIT
- PRODUCT NAME:
- CONNECTING ROD KIT
- RIDING STYLE:
- OFF-ROAD
- ENGINE TYPE:
- 4-STROKE
$174.00 -
Wossner Connecting Rod KTM 85SX 2003-2012 P2006
WOSSNER
$112.00Upgrade your KTM 85XS with the WOSSNER Connecting Rod Kit, meticulously engineered for optimal performance and durability. This kit includes everything necessary for a complete crankshaft rebuild, ensuring compatibility with OEM components and enhancing...09230570- SKU:
- 09230570
- Availability:
- Ships Same Business Day
- Weight:
- 0.71 LBS
- PRODUCT NAME:
- CONNECTING ROD KIT
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- ENGINE TYPE:
- 2-STROKE
- STYLE:
- STANDARD
$112.00Qty in Cart: 0Quantity:Price:$112.00Subtotal: -
Wossner Connecting Rod Yamaha YZ125 1986-1996 P2047
WOSSNER
$122.00Enhance the performance and reliability of your YZ125 with the WOSSNER Connecting Rod Kit. Engineered with precision, this kit includes everything necessary for a complete crankshaft rebuild, ensuring optimal compatibility and durability. Crafted from...09230573- SKU:
- 09230573
- Availability:
- Ships Same Business Day
- Weight:
- 0.75 LBS
- PRODUCT NAME:
- CONNECTING ROD KIT
- ENGINE TYPE:
- 2-STROKE
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- STYLE:
- STANDARD
$122.00Qty in Cart: 0Quantity:Price:$122.00Subtotal: -
Wossner Connecting Rod Kit for Honda CR250R 1978-2001 P2021
WOSSNER
$122.00Elevate your engine performance with the WOSSNER Connecting Rod CR250 P2021. This premium connecting rod kit is meticulously engineered to ensure optimal fit and durability, making it an essential component for your crankshaft rebuild. Crafted from...09230389- SKU:
- 09230389
- Availability:
- Ships Same Business Day
- Weight:
- 1.25 LBS
- ENGINE TYPE:
- 2-STROKE
- PRODUCT NAME:
- CONNECTING ROD KIT
- RIDING STYLE:
- ATV
- RIDING STYLE:
- OFF-ROAD
- RIDING STYLE:
- STREET
- UNITS:
- KIT
- STYLE:
- STANDARD
$122.00 -
Wossner 53.96mm Piston Kit for Honda CR125R 1992-1999 8020DB
WOSSNER
$122.00Experience superior performance with the WOSSNER Piston Kit 8020DB, designed for 2-stroke engines. Engineered with precision and crafted from high-quality materials, this piston kit ensures optimal efficiency, reduced friction, and enhanced durability...09104723- SKU:
- 09104723
- Availability:
- Ships Same Business Day
- Weight:
- 0.35 LBS
- BORE - OVERSIZE METRIC:
- +0.01 MM
- ENGINE TYPE:
- 2-STROKE
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- SINGLE RING
- UNITS:
- KIT
- BORE - OVERSIZE:
- +0,01 MM
- BORE SIZE METRIC:
- 54.01 MM
- PISTON MATERIAL:
- ALUMINUM ALLOY
- PISTON MATERIAL:
- FORGED
- PISTON SIZE METRIC:
- 53.96 MM
- DISPLACEMENT:
- 125 CC
- MODEL:
- STANDARD SERIES
- PRODUCT NAME:
- PISTON KIT
$122.00Qty in Cart: 0Quantity:Price:$122.00Subtotal: -
Wossner Piston Kit 66.37mm Yamaha YZ250 1999-2023 8216DC
WOSSNER
$152.00Experience unparalleled performance and reliability with the WOSSNER Piston Kit 8216DC. Designed for 2-stroke engines, this piston kit combines advanced engineering and high-quality materials to elevate your engine's efficiency and longevity. Trust in...09104879- SKU:
- 09104879
- Availability:
- Ships Same Business Day
- Weight:
- 0.70 LBS
- BORE - OVERSIZE:
- +0,02 MM
- BORE - OVERSIZE METRIC:
- +0.02 MM
- MODEL:
- STANDARD SERIES
- PRODUCT NAME:
- PISTON KIT
- BORE SIZE METRIC:
- 66.42 MM
- PISTON MATERIAL:
- FORGED
- UNITS:
- KIT
- DISPLACEMENT:
- 249 CC
- TYPE:
- DUAL RING
- ENGINE TYPE:
- 2-STROKE
- PISTON MATERIAL:
- ALUMINUM ALLOY
- PISTON SIZE METRIC:
- 66.37 MM
- RIDING STYLE:
- OFF-ROAD
$152.00 -
Wossner Piston Kit 44.98mm KTM 65 SX 2009-2023 8241DC
WOSSNER
$102.00Elevate your engine's performance with the WOSSNER Piston Kit 8241DC, designed specifically for 2-stroke applications. This premium kit combines innovative engineering with high-quality materials, ensuring optimal efficiency and durability for your...09104892- SKU:
- 09104892
- Availability:
- Ships Same Business Day
- Weight:
- 0.30 LBS
- BORE - OVERSIZE METRIC:
- +0.02 MM
- MODEL:
- STANDARD SERIES
- PISTON SIZE METRIC:
- 44.98 MM
- PRODUCT NAME:
- PISTON KIT
- ENGINE TYPE:
- 2-STROKE
- TYPE:
- SINGLE RING
- BORE - OVERSIZE:
- +0,02 MM
- PISTON MATERIAL:
- FORGED
- UNITS:
- KIT
- BORE SIZE METRIC:
- 45.04 MM
- DISPLACEMENT:
- 64 CC
- PISTON MATERIAL:
- ALUMINUM ALLOY
- RIDING STYLE:
- OFF-ROAD
$102.00Qty in Cart: 0Quantity:Price:$102.00Subtotal: -
Wossner Single Ring Piston Kit Kawasaki KX125 1990 8106DA
WOSSNER
$117.95Experience unparalleled performance with the WOSSNER Piston Kit 8106DA, meticulously engineered for 2-stroke engines. Crafted from premium materials, this piston kit ensures superior durability and efficiency, enhancing your engine's power and longevity...09105531- SKU:
- 09105531
- Availability:
- Ships Same Business Day
- Weight:
- 0.40 LBS
- BORE SIZE METRIC:
- 56.00 MM
- DISPLACEMENT:
- 124 CC
- ENGINE TYPE:
- 2-STROKE
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- SINGLE RING
- UNITS:
- KIT
- PISTON SIZE METRIC:
- 55.94 MM
- BORE - OVERSIZE:
- STANDARD
- PISTON MATERIAL:
- ALUMINUM ALLOY
- PISTON MATERIAL:
- FORGED
- BORE - OVERSIZE METRIC:
- STANDARD
- MODEL:
- STANDARD SERIES
- PRODUCT NAME:
- PISTON KIT
$117.95Qty in Cart: 0Quantity:Price:$117.95Subtotal: -
Wossner Piston Kit Yamaha YZ250 1988-1991 68.44mm 8134D050
WOSSNER
$152.00Experience unparalleled performance with the WOSSNER Piston Kit 8134D050, designed specifically for 2-stroke engines. Crafted from high-quality materials and engineered for precision, this piston kit ensures optimal efficiency and durability, making it...09105547- SKU:
- 09105547
- Availability:
- Ships Same Business Day
- Weight:
- 0.75 LBS
- DISPLACEMENT:
- 246 CC
- MODEL:
- STANDARD SERIES
- PRODUCT NAME:
- PISTON KIT
- TYPE:
- DUAL RING
- PISTON MATERIAL:
- ALUMINUM ALLOY
- PISTON MATERIAL:
- FORGED
- PISTON SIZE METRIC:
- 68.44 MM
- BORE - OVERSIZE METRIC:
- +0.50 MM
- BORE SIZE METRIC:
- 68.50 MM
- BORE - OVERSIZE:
- +0,50 MM
- ENGINE TYPE:
- 2-STROKE
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
$152.00Qty in Cart: 0Quantity:Price:$152.00Subtotal: -
Wossner Yamaha YZ250 1988-1991 68.94mm Piston Kit 8134D100
WOSSNER
$152.00Experience the pinnacle of performance with the WOSSNER Piston Kit 8134D100, engineered for superior efficiency and reliability in 2-stroke engines. Crafted with precision, this piston kit enhances your engine's capabilities while ensuring a quieter...09105548- SKU:
- 09105548
- Availability:
- Ships Same Business Day
- Weight:
- 0.80 LBS
- BORE - OVERSIZE:
- +1,00 MM
- DISPLACEMENT:
- 246 CC
- MODEL:
- STANDARD SERIES
- PRODUCT NAME:
- PISTON KIT
- TYPE:
- DUAL RING
- BORE - OVERSIZE METRIC:
- +1.00 MM
- BORE SIZE METRIC:
- 69.00 MM
- PISTON MATERIAL:
- ALUMINUM ALLOY
- PISTON MATERIAL:
- FORGED
- PISTON SIZE METRIC:
- 68.94 MM
- ENGINE TYPE:
- 2-STROKE
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
$152.00Qty in Cart: 0Quantity:Price:$152.00Subtotal: -
Wossner Piston Kit 67.94mm 2-Stroke 246cc 8134DA
WOSSNER
$152.00Experience unparalleled performance with the WOSSNER Piston Kit 8134DA, expertly crafted for 2-stroke engines. This premium kit includes everything you need for a seamless installation, featuring advanced materials and engineering to enhance your...09105551- SKU:
- 09105551
- Availability:
- Ships Same Business Day
- Weight:
- 0.76 LBS
- DISPLACEMENT:
- 246 CC
- ENGINE TYPE:
- 2-STROKE
- PISTON SIZE METRIC:
- 67.94 MM
- PRODUCT NAME:
- PISTON KIT
- TYPE:
- DUAL RING
- BORE - OVERSIZE METRIC:
- STANDARD
- BORE SIZE METRIC:
- 68.00 MM
- MODEL:
- STANDARD SERIES
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- BORE - OVERSIZE:
- STANDARD
- PISTON MATERIAL:
- ALUMINUM ALLOY
- PISTON MATERIAL:
- FORGED
$152.00Qty in Cart: 0Quantity:Price:$152.00Subtotal: -
Wrench Rabbit Engine Rebuild Kit for KTM 125 SX 2007-2015 WR101-216
WRENCH RABBIT
$1,013.95Revitalize your KTM WR101-128 with the WRENCH RABBIT Engine Kit, designed for a seamless and professional rebuild. This comprehensive kit includes all essential components, ensuring your engine performs at its best. Experience enhanced reliability and...09031102- SKU:
- 09031102
- Availability:
- Ships Same Business Day
- Weight:
- 11.55 LBS
- ENGINE TYPE:
- 2-STROKE
- MODEL:
- WRENCH RABBIT
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- FEATURES:
- STANDARD COMPRESSION PISTON
- PRODUCT NAME:
- REBUILD KIT
- TYPE:
- ENGINE
$1,013.95Qty in Cart: 0Quantity:Price:$1,013.95Subtotal: -
Wrench Rabbit Complete Engine Rebuild Kit for Yamaha YZ85 2002-2016 WR101-089
WRENCH RABBIT
$1,183.95Revitalize your Yamaha WR101-146 with the WRENCH RABBIT Engine Kit, a comprehensive solution designed for a seamless and professional rebuild. This all-in-one kit includes high-quality components to ensure optimal performance and durability, making it...09031116- SKU:
- 09031116
- Availability:
- Ships Same Business Day
- Weight:
- 13.25 LBS
- FEATURES:
- STANDARD COMPRESSION PISTON
- PRODUCT NAME:
- REBUILD KIT
- TYPE:
- ENGINE
- UNITS:
- KIT
- ENGINE TYPE:
- 4-STROKE
- MODEL:
- WRENCH RABBIT
- RIDING STYLE:
- OFF-ROAD
$1,183.95 -
Wrench Rabbit Complete Engine Rebuild Kit for 2013 Suzuki RMZ450 WR101-149
WRENCH RABBIT
$1,156.95Revitalize your Suzuki WR101-149 with the WRENCH RABBIT Engine Kit, designed for a seamless and professional rebuild. This comprehensive kit includes high-quality components that ensure top performance and longevity, making it the ideal choice for...09031118- SKU:
- 09031118
- Availability:
- Ships Same Business Day
- Weight:
- 15.00 LBS
- FEATURES:
- STANDARD COMPRESSION PISTON
- PRODUCT NAME:
- REBUILD KIT
- TYPE:
- ENGINE
- ENGINE TYPE:
- 4-STROKE
- MODEL:
- WRENCH RABBIT
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
$1,156.95Qty in Cart: 0Quantity:Price:$1,156.95Subtotal: -
Wrench Rabbit Engine Rebuild Kit for 2013-2016 Honda CRF450R WR101-150
WRENCH RABBIT
$1,132.95Transform your Honda WR101-150 with the WRENCH RABBIT Engine Kit, designed for a seamless and professional rebuild. This all-inclusive kit features high-quality components to ensure your engine runs smoothly and efficiently, making it the ultimate choice...09031119- SKU:
- 09031119
- Availability:
- Ships Same Business Day
- Weight:
- 16.30 LBS
- FEATURES:
- STANDARD COMPRESSION PISTON
- PRODUCT NAME:
- REBUILD KIT
- TYPE:
- ENGINE
- ENGINE TYPE:
- 4-STROKE
- MODEL:
- WRENCH RABBIT
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
$1,132.95 -
BOYESEN Ignition Cover - Black - CR250 SC-02AB
BOYESEN
$87.95Factory Ignition Cover SC02AB Professional appearance enhances your bike's aesthetics. Seals effectively to protect the engine from dirt and water. Durable design outlasts standard stock covers. Constructed from premium-grade aluminum...SC02AB- SKU:
- SC02AB
- Availability:
- Ships Same Business Day
- Weight:
- 0.60 LBS
- UNITS:
- EACH
- COLOR/FINISH:
- POWDER-COATED
- MATERIAL:
- ALUMINUM
- MODEL:
- FACTORY RACING
- PRODUCT NAME:
- COVER
- COLOR/FINISH:
- BLACK
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- IGNITION
$87.95Qty in Cart: 0Quantity:Price:$87.95Subtotal: -
BOYESEN Impeller Water Pump - Magnesium - YZ125 WPK-31AM
BOYESEN
$219.95Increased coolant flow at all rpm ranges, Patented Nautilus-style impeller for hydrodynamic efficiency09401472- SKU:
- 09401472
- Availability:
- Ships Same Business Day
- Weight:
- 0.40 LBS
- COLOR/FINISH:
- GOLD
- MODEL:
- SUPERCOOLER
- RIDING STYLE:
- OFF-ROAD
- STYLE:
- NAUTILUS
- COLOR/FINISH:
- MAGNESIUM
- MATERIAL:
- ALUMINUM
- PRODUCT NAME:
- COVER
- TYPE:
- WATER PUMP
- UNITS:
- KIT
- PRODUCT NAME:
- IMPELLER
- BASE COLOR:
- GOLD
$219.95Qty in Cart: 0Quantity:Price:$219.95Subtotal: -
BOYESEN Ignition Cover - Gold SC-41M
BOYESEN
$87.95Look like a professional with the Factory Ignition Cover, Seals properly, guarding inside of engine from dirt and water and outlasts stock covers, Boyesen Factory Covers are cast from the highest grade of aluminum and are strong yet lightweight,...09400700- SKU:
- 09400700
- Availability:
- Ships Same Business Day
- Weight:
- 0.71 LBS
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- IGNITION
- COLOR/FINISH:
- MAGNESIUM
- COLOR/FINISH:
- POWDER-COATED
- MATERIAL:
- ALUMINUM
- MODEL:
- FACTORY RACING
- PRODUCT NAME:
- COVER
- RIDING STYLE:
- STREET
- UNITS:
- EACH
$87.95Qty in Cart: 0Quantity:Price:$87.95Subtotal: -
BOYESEN Clutch Cover - Gold - CR250/500 CC-02M
BOYESEN
$95.95Set your ride apart from the rest with the ultimate look in race performance, Lightweight factory clutch covers provide years of outstanding protection, Individually surfaced for a perfect, leak-free fit, Super-tough, powder-coated finish resists...09400222- SKU:
- 09400222
- Availability:
- Ships Same Business Day
- Weight:
- 0.55 LBS
- COLOR/FINISH:
- MAGNESIUM
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- CLUTCH
- COLOR/FINISH:
- POWDER-COATED
- MODEL:
- FACTORY RACING
- PRODUCT NAME:
- COVER
- UNITS:
- EACH
$95.95Qty in Cart: 0Quantity:Price:$95.95Subtotal:
