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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JE PISTONS Piston Kit 323557
JE PISTONS
$309.99When you're pushing your engine to its limits in competition, your pistons need to handle extreme pressures and temperatures without compromise. JE Pistons' 323557 kit delivers the precision engineering and material science required for...09105932- SKU:
- 09105932
- Availability:
- Ships Same Business Day
- Weight:
- 1.36 LBS
- BORE - OVERSIZE METRIC:
- STANDARD
- COMPRESSION RATIO IMPERIAL:
- 14.0:1
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- BORE - OVERSIZE:
- STANDARD
- PISTON MATERIAL:
- FORGED 2618 ALUMINUM
- PRODUCT NAME:
- PISTON KIT
- STYLE:
- PRO SERIES
- BORE SIZE METRIC:
- 77.00 MM
- DISPLACEMENT:
- 250 CC
- PISTON HEAD SHAPE:
- DOMED
- TYPE:
- FORGED SIDE RELIEF DESIGN
$309.99 -
JE PISTONS Piston Kit 323558
JE PISTONS
$309.99When you're pushing your engine to the absolute limit in competition, your pistons need to survive extreme pressures and temperatures without compromise. JE Pistons' Pro Series 323558 kit delivers the strength and precision engineering that professional...09105933- SKU:
- 09105933
- Availability:
- Ships Same Business Day
- Weight:
- 1.36 LBS
- BORE - OVERSIZE METRIC:
- STANDARD
- BORE - OVERSIZE:
- STANDARD
- BORE SIZE METRIC:
- 77.00 MM
- PISTON MATERIAL:
- FORGED 2618 ALUMINUM
- PRODUCT NAME:
- PISTON KIT
- STYLE:
- PRO SERIES
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- COMPRESSION RATIO IMPERIAL:
- 14.5:1
- DISPLACEMENT:
- 250 CC
- PISTON HEAD SHAPE:
- DOMED
- TYPE:
- FORGED SIDE RELIEF DESIGN
$309.99 -
JE PISTONS Piston Kit 324915
JE PISTONS
$329.99When you're pushing your engine to the limit in competition, your pistons need to handle extreme combustion pressures and sustained high RPM operation without compromise. JE PISTONS' Pro Series kit combines advanced metallurgy with precision engineering...09105939- SKU:
- 09105939
- Availability:
- Ships Same Business Day
- Weight:
- 1.01 LBS
- DISPLACEMENT:
- 450 CC
- PRODUCT NAME:
- PISTON KIT
- BORE - OVERSIZE METRIC:
- STANDARD
- BORE SIZE METRIC:
- 97.00 MM
- COMPRESSION RATIO IMPERIAL:
- 14.0:1
- PISTON HEAD SHAPE:
- DOMED
- UNITS:
- KIT
- PISTON MATERIAL:
- FORGED 2618 ALUMINUM
- TYPE:
- FORGED SIDE RELIEF DESIGN
- BORE - OVERSIZE:
- STANDARD
- RIDING STYLE:
- OFF-ROAD
- STYLE:
- PRO SERIES
$329.99 -
JE PISTONS Piston Kit 325025
JE PISTONS
$329.99When you're pushing your engine to the absolute limit in competition, your pistons need to be engineered for extreme duty—not just adequate. JE Pistons' 325025 kit delivers the strength and precision required for professional-level racing applications,...09105940- SKU:
- 09105940
- Availability:
- Ships Same Business Day
- Weight:
- 1.16 LBS
- UNITS:
- KIT
- WALL THICKNESS IMPERIAL:
- 0.160'
- DISPLACEMENT:
- 478 CC
- PISTON HEAD SHAPE:
- DISHED
- PRODUCT NAME:
- PISTON KIT
- RIDING STYLE:
- ATV
- BORE SIZE METRIC:
- 98.00 MM
- COMPRESSION RATIO IMPERIAL:
- 13.5:1
- WALL THICKNESS:
- 0,160'
$329.99 -
JE PISTONS Piston Kit 325027
JE PISTONS
$329.99When you're pushing your engine to the absolute limit—whether on the track or in competition—your pistons need to withstand extreme combustion pressures and temperatures without compromise. JE PISTONS 325027 Pro Series pistons are purpose-built for...09105941- SKU:
- 09105941
- Availability:
- Ships Same Business Day
- Weight:
- 1.36 LBS
- PISTON HEAD SHAPE:
- DOMED
- UNITS:
- KIT
- WALL THICKNESS IMPERIAL:
- 0.160'
- PRODUCT NAME:
- PISTON KIT
- RIDING STYLE:
- ATV
- WALL THICKNESS:
- 0,160'
- BORE SIZE METRIC:
- 99.00 MM
- DISPLACEMENT:
- 477 CC
- COMPRESSION RATIO IMPERIAL:
- 13.5:1
$329.99Qty in Cart: 0Quantity:Price:$329.99Subtotal: -
JE PISTONS Piston Kit 345054
JE PISTONS
$424.99When you're pushing your engine to the absolute limit—whether on the track or in competition—factory pistons simply won't cut it. JE PISTONS' 345054 kit delivers the strength, precision, and weight optimization that separates winners from the rest. Built...09105943- SKU:
- 09105943
- Availability:
- Ships Same Business Day
- Weight:
- 1.36 LBS
- BORE - OVERSIZE:
- STANDARD
- RIDING STYLE:
- OFF-ROAD
- STYLE:
- PRO SERIES
- UNITS:
- KIT
- PISTON HEAD SHAPE:
- DOMED
- TYPE:
- FORGED SIDE RELIEF DESIGN
- BORE - OVERSIZE METRIC:
- STANDARD
- BORE SIZE METRIC:
- 96.00 MM
- COMPRESSION RATIO IMPERIAL:
- 13.5:1
- DISPLACEMENT:
- 449 CC
- PISTON MATERIAL:
- FORGED 2618 ALUMINUM
- PRODUCT NAME:
- PISTON KIT
$424.99 -
JE PISTONS Piston Kit 345056
JE PISTONS
$424.99When you're pushing your engine to the absolute limit in competition, your pistons need to survive extreme pressures and temperatures without compromise. JE PISTONS' Pro Series 345056 kit delivers the precision engineering and materials science required...09105945- SKU:
- 09105945
- Availability:
- Ships Same Business Day
- Weight:
- 1.01 LBS
- BORE - OVERSIZE:
- STANDARD
- RIDING STYLE:
- OFF-ROAD
- STYLE:
- PRO SERIES
- UNITS:
- KIT
- BORE - OVERSIZE METRIC:
- STANDARD
- COMPRESSION RATIO IMPERIAL:
- 14.5:1
- PISTON HEAD SHAPE:
- DOMED
- PISTON MATERIAL:
- FORGED 2618 ALUMINUM
- TYPE:
- FORGED SIDE RELIEF DESIGN
- BORE SIZE METRIC:
- 96.00 MM
- DISPLACEMENT:
- 449 CC
- PRODUCT NAME:
- PISTON KIT
$424.99 -
JE PISTONS Piston Kit 345193
JE PISTONS
$839.99If you're running a high-displacement or boosted engine in a competition setting, you need pistons engineered to handle extreme pressure and heat cycles without compromise. JE PISTONS' Pro Series delivers the precision machining, internal bracing, and...09105947- SKU:
- 09105947
- Availability:
- Ships Same Business Day
- Weight:
- 2.66 LBS
- DISPLACEMENT:
- 998 CC
- UNITS:
- KIT
- BORE SIZE METRIC:
- 80.00 MM
- COMPRESSION RATIO IMPERIAL:
- 11.5:1
- PRODUCT NAME:
- PISTON KIT
- WALL THICKNESS:
- 0,160'
- WALL THICKNESS IMPERIAL:
- 0.160'
- PISTON HEAD SHAPE:
- DOMED
- RIDING STYLE:
- UTV
$839.99 -
JE PISTONS Piston Kit 345200
JE PISTONS
$424.99When you're pushing your engine to its limits in competition, your pistons need to withstand extreme pressures and temperatures without compromise. JE PISTONS' Pro Series 345200 kit delivers the precision engineering and durability demanded by...09105948- SKU:
- 09105948
- Availability:
- Ships Same Business Day
- Weight:
- 0.76 LBS
- BORE - OVERSIZE METRIC:
- STANDARD
- DISPLACEMENT:
- 249 CC
- PISTON MATERIAL:
- FORGED 2618 ALUMINUM
- BORE - OVERSIZE:
- STANDARD
- BORE SIZE METRIC:
- 77.00 MM
- PRODUCT NAME:
- PISTON KIT
- STYLE:
- PRO SERIES
- RIDING STYLE:
- OFF-ROAD
- COMPRESSION RATIO IMPERIAL:
- 14.0:1
- PISTON HEAD SHAPE:
- DOMED
- TYPE:
- FORGED SIDE RELIEF DESIGN
- UNITS:
- KIT
$424.99 -
JE PISTONS Piston Kit 345055
JE PISTONS
$424.99When you're pushing an engine to its absolute limits, stock pistons won't cut it. JE PISTONS 345055 Pro Series pistons are purpose-built for extreme competition applications, delivering the precision engineering and durability you need when every tenth...09105944- SKU:
- 09105944
- Availability:
- Ships Same Business Day
- Weight:
- 1.11 LBS
- BORE - OVERSIZE:
- STANDARD
- RIDING STYLE:
- OFF-ROAD
- STYLE:
- PRO SERIES
- PISTON MATERIAL:
- FORGED 2618 ALUMINUM
- TYPE:
- FORGED SIDE RELIEF DESIGN
- BORE - OVERSIZE METRIC:
- STANDARD
- COMPRESSION RATIO IMPERIAL:
- 14.0:1
- DISPLACEMENT:
- 449 CC
- PISTON HEAD SHAPE:
- DOMED
- UNITS:
- KIT
- BORE SIZE METRIC:
- 96.00 MM
- PRODUCT NAME:
- PISTON KIT
$424.99 -
JE PISTONS Piston Kit 130798
JE PISTONS
$269.99When you're pushing your engine to its limits in competition, factory pistons simply won't cut it. JE PISTONS' Pro Series kit delivers the precision engineering and material science required to survive extreme boost, high RPM, and sustained load—without...09105835- SKU:
- 09105835
- Availability:
- Ships Same Business Day
- Weight:
- 1.31 LBS
- DISPLACEMENT:
- 540 CC
- PISTON HEAD SHAPE:
- DOMED
- TYPE:
- ROUND FORGED DESIGN
- BORE - OVERSIZE METRIC:
- +3.00 MM
- PISTON MATERIAL:
- FORGED 2618 ALUMINUM
- PRODUCT NAME:
- PISTON KIT
- RIDING STYLE:
- STREET
- STYLE:
- JE PISTON
- BORE - OVERSIZE:
- +3,00 MM
- BORE SIZE METRIC:
- 90.00 MM
- COMPRESSION RATIO IMPERIAL:
- 11.0:1
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
$269.99 -
Cylinder Works Big Bore Gasket Kit Honda CRF450R 2002-2008 11002-G01
CYLINDER WORKS
$77.95If you're running a CRF450R between 2002-2008 and want measurable gains in displacement and compression without extensive machine work, the Cylinder Works Big Bore Gasket Kit delivers a complete, bolt-on solution. This kit eliminates guesswork by pairing...09341522- SKU:
- 09341522
- Availability:
- Ships Same Business Day
- Weight:
- 0.16 LBS
- MATERIAL:
- NICKEL SILICON CARBIDE
- UNITS:
- KIT
- TYPE:
- TOP END
- BORE SIZE METRIC:
- OVERSIZE (+4.00 MM)
- PRODUCT NAME:
- GASKET KIT
- RIDING STYLE:
- OFF-ROAD
- STYLE:
- BIG BORE
$77.95 -
Cylinder Works Big Bore Gasket Kit YFZ 450 R 2009-2024 21002-G01
CYLINDER WORKS
$93.95When you're running a YFZ 450 R at the track or trail, OEM gaskets won't cut it—they're engineered for stock power levels, not the abuse of serious riding. The Cylinder Works Big Bore Gasket Kit 21002-G01 is a complete solution that pairs...09341523- SKU:
- 09341523
- Availability:
- Ships Same Business Day
- Weight:
- 0.16 LBS
- MATERIAL:
- NICKEL SILICON CARBIDE
- UNITS:
- KIT
- ENGINE TYPE:
- 4-STROKE
- RIDING STYLE:
- OFF-ROAD
- PRODUCT NAME:
- GASKET KIT
- STYLE:
- BIG BORE
- BORE SIZE METRIC:
- OVERSIZED (+3.00 MM)
- TYPE:
- TOP END
$93.95 -
Cylinder Works Big Bore Gasket Kit Kawasaki KX250F 2004-2008 31001-G01
CYLINDER WORKS
$102.95The Cylinder Works Big Bore Gasket Kit delivers measurable performance gains by increasing displacement and compression without requiring machine work or extensive modifications. If you're looking to extract more power from your KX250F while maintaining...09341525- SKU:
- 09341525
- Availability:
- Ships Same Business Day
- Weight:
- 0.15 LBS
- MATERIAL:
- NICKEL SILICON CARBIDE
- STYLE:
- BIG BORE
- RIDING STYLE:
- OFF-ROAD
- PRODUCT NAME:
- GASKET KIT
- UNITS:
- KIT
- BORE SIZE METRIC:
- OVERSIZED (+3.00 MM)
- TYPE:
- TOP END
$102.95 -
On Sale
ATHENA Water Pump Gasket Kit - Suzuki P400510475004
ATHENA
MSRP: $39.95Now: $36.00Was: $39.95Cooling system leaks compromise engine reliability and performance—they demand immediate attention with OEM-quality replacement gaskets. The ATHENA Water Pump Gasket Kit delivers factory-spec sealing surfaces without the dealer markup, ensuring your...09346083- SKU:
- 09346083
- Availability:
- Ships Same Business Day
- Weight:
- 0.10 LBS
- PRODUCT NAME:
- GASKET KIT
- TYPE:
- WATER PUMP
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
MSRP: $39.95Now: $36.00Was: $39.95Qty in Cart: 0Quantity:Price:MSRP: $39.95Now: $36.00Was: $39.95Subtotal: -
On Sale
ATHENA Water Pump Gasket Kit - Yamaha P400485475002
ATHENA
MSRP: $37.95Now: $34.00Was: $37.95Seal leaks before they compromise your engine's cooling system and cost you race time. The ATHENA Water Pump Gasket Kit delivers OEM-grade sealing components in a single package, eliminating the frustration of sourcing gaskets and seals individually...09346084- SKU:
- 09346084
- Availability:
- Ships Same Business Day
- Weight:
- 0.10 LBS
- PRODUCT NAME:
- GASKET KIT
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- TYPE:
- WATER PUMP
MSRP: $37.95Now: $34.00Was: $37.95Qty in Cart: 0Quantity:Price:MSRP: $37.95Now: $34.00Was: $37.95Subtotal: -
On Sale
ATHENA Water Pump Gasket Kit - Yamaha P400485475003
ATHENA
MSRP: $38.95Now: $35.00Was: $38.95Water pump gasket failure is a common culprit behind coolant leaks and engine overheating—issues that can sideline your bike or damage your engine if left unchecked. The ATHENA Water Pump Gasket Kit provides all the OEM-specification seals and gaskets...09346085- SKU:
- 09346085
- Availability:
- Ships Same Business Day
- Weight:
- 0.20 LBS
- PRODUCT NAME:
- GASKET KIT
- TYPE:
- WATER PUMP
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
MSRP: $38.95Now: $35.00Was: $38.95 -
On Sale
ATHENA Water Pump Gasket Kit - Yamaha P400485475004
ATHENA
MSRP: $34.95Now: $31.00Was: $34.95A leaking water pump doesn't just waste coolant—it compromises engine temperature control and can lead to catastrophic overheating. The ATHENA Water Pump Gasket Kit delivers OEM-quality sealing surfaces to restore your cooling system's integrity without...09346086- SKU:
- 09346086
- Availability:
- Ships Same Business Day
- Weight:
- 0.15 LBS
- PRODUCT NAME:
- GASKET KIT
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- TYPE:
- WATER PUMP
MSRP: $34.95Now: $31.00Was: $34.95Qty in Cart: 0Quantity:Price:MSRP: $34.95Now: $31.00Was: $34.95Subtotal: -
On Sale
ATHENA Water Pump Gasket Kit - Yamaha P400485475006
ATHENA
MSRP: $37.95Now: $34.00Was: $37.95Coolant leaks and seal failures compromise engine reliability and performance—two things you can't afford on the track or in your build. The ATHENA Water Pump Gasket Kit provides OEM-quality sealing surfaces and precision-fit components to restore your...09346088- SKU:
- 09346088
- Availability:
- Ships Same Business Day
- Weight:
- 0.25 LBS
- PRODUCT NAME:
- GASKET KIT
- TYPE:
- WATER PUMP
- UNITS:
- KIT
- ENGINE TYPE:
- 4-STROKE
- RIDING STYLE:
- OFF-ROAD
MSRP: $37.95Now: $34.00Was: $37.95Qty in Cart: 0Quantity:Price:MSRP: $37.95Now: $34.00Was: $37.95Subtotal: -
On Sale
ATHENA Gasket Kit - CRF230F P400210160316
ATHENA
MSRP: $37.95Now: $34.00Was: $37.95The ATHENA Gasket Kit is engineered for CRF230F owners looking to rebuild their engine with OEM-quality components that deliver reliable performance and longevity. This complete kit eliminates the guesswork of sourcing individual gaskets and seals,...09344814- SKU:
- 09344814
- Availability:
- Ships Same Business Day
- Weight:
- 0.10 LBS
- BORE SIZE METRIC:
- 67.00 MM
- DISPLACEMENT:
- 233 CC
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- TOP END
- UNITS:
- KIT
- BORE SIZE:
- 67,00 MM
- PRODUCT NAME:
- GASKET KIT
MSRP: $37.95Now: $34.00Was: $37.95Qty in Cart: 0Quantity:Price:MSRP: $37.95Now: $34.00Was: $37.95Subtotal:
