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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On Sale
PROX Crank Seal Kit - KTM50 42.6011
PROX
MSRP: $14.95Now: $13.00Was: $14.95OEM quality, All seals necessary for complete crank rebuild included09350605- SKU:
- 09350605
- Availability:
- Ships Same Business Day
- Weight:
- 0.10 LBS
- TYPE:
- OIL
- PRODUCT NAME:
- SEAL
- APPLICATION:
- CRANKSHAFT
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
MSRP: $14.95Now: $13.00Was: $14.95Qty in Cart: 0Quantity:Price:MSRP: $14.95Now: $13.00Was: $14.95Subtotal: -
On Sale
PROX Crank Seal Kit - RMZ250 42.3340
PROX
MSRP: $24.95Now: $21.00Was: $24.95OEM quality, All seals necessary for complete crank rebuild included09350460- SKU:
- 09350460
- Availability:
- Ships Same Business Day
- Weight:
- 0.10 LBS
- PRODUCT NAME:
- SEAL
- TYPE:
- OIL
- APPLICATION:
- CRANKSHAFT
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
MSRP: $24.95Now: $21.00Was: $24.95Qty in Cart: 0Quantity:Price:MSRP: $24.95Now: $21.00Was: $24.95Subtotal: -
On Sale
PROX Gasket Kit - Complete - Honda 34.1218
PROX
MSRP: $89.95Now: $76.00Was: $89.95PROX Gasket Kit - Complete - Honda09345519- SKU:
- 09345519
- Availability:
- Ships Same Business Day
- Weight:
- 0.10 LBS
- ENGINE TYPE:
- 2-STROKE
- PRODUCT NAME:
- GASKET KIT
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- COMPLETE
- UNITS:
- KIT
MSRP: $89.95Now: $76.00Was: $89.95Qty in Cart: 0Quantity:Price:MSRP: $89.95Now: $76.00Was: $89.95Subtotal: -
On Sale
PROX Gasket Kit - Complete - Honda 34.1220
PROX
MSRP: $89.95Now: $76.00Was: $89.95PROX Gasket Kit - Complete - Honda09345520- SKU:
- 09345520
- Availability:
- Ships Same Business Day
- Weight:
- 0.20 LBS
- ENGINE TYPE:
- 2-STROKE
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- COMPLETE
- UNITS:
- KIT
- PRODUCT NAME:
- GASKET KIT
MSRP: $89.95Now: $76.00Was: $89.95 -
On Sale
PROX Gasket Kit - Complete - Honda 34.1224
PROX
MSRP: $104.95Now: $89.00Was: $104.95PROX Gasket Kit - Complete - Honda09345522- SKU:
- 09345522
- Availability:
- Ships Same Business Day
- Weight:
- 0.20 LBS
- PRODUCT NAME:
- GASKET KIT
- ENGINE TYPE:
- 2-STROKE
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- COMPLETE
- UNITS:
- KIT
MSRP: $104.95Now: $89.00Was: $104.95Qty in Cart: 0Quantity:Price:MSRP: $104.95Now: $89.00Was: $104.95Subtotal: -
On Sale
PROX Gasket Kit - Complete - Honda 34.1322
PROX
MSRP: $99.95Now: $85.00Was: $99.95PROX Gasket Kit - Complete - Honda09345526- SKU:
- 09345526
- Availability:
- Ships Same Business Day
- Weight:
- 0.40 LBS
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- COMPLETE
- UNITS:
- KIT
- ENGINE TYPE:
- 4-STROKE
- PRODUCT NAME:
- GASKET KIT
MSRP: $99.95Now: $85.00Was: $99.95Qty in Cart: 0Quantity:Price:MSRP: $99.95Now: $85.00Was: $99.95Subtotal: -
On Sale
PROX Gasket Kit - Complete - Honda 34.1334
PROX
MSRP: $184.95Now: $157.00Was: $184.95PROX Gasket Kit - Complete - Honda09345529- SKU:
- 09345529
- Availability:
- Ships Same Business Day
- Weight:
- 0.40 LBS
- ENGINE TYPE:
- 4-STROKE
- PRODUCT NAME:
- GASKET KIT
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- COMPLETE
- UNITS:
- KIT
MSRP: $184.95Now: $157.00Was: $184.95Qty in Cart: 0Quantity:Price:MSRP: $184.95Now: $157.00Was: $184.95Subtotal: -
On Sale
PROX Gasket Kit - Complete - Honda 34.1416
PROX
MSRP: $124.95Now: $106.00Was: $124.95PROX Gasket Kit - Complete - Honda09345535- SKU:
- 09345535
- Availability:
- Ships Same Business Day
- Weight:
- 0.40 LBS
- ENGINE TYPE:
- 4-STROKE
- PRODUCT NAME:
- GASKET KIT
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- COMPLETE
- UNITS:
- KIT
MSRP: $124.95Now: $106.00Was: $124.95 -
On Sale
PROX Gasket Kit - Complete - Suzuki 34.3122
PROX
MSRP: $74.95Now: $64.00Was: $74.95PROX Gasket Kit - Complete - Suzuki09345569- SKU:
- 09345569
- Availability:
- Ships Same Business Day
- Weight:
- 0.10 LBS
- PRODUCT NAME:
- GASKET KIT
- UNITS:
- KIT
- ENGINE TYPE:
- 2-STROKE
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- COMPLETE
MSRP: $74.95Now: $64.00Was: $74.95Qty in Cart: 0Quantity:Price:MSRP: $74.95Now: $64.00Was: $74.95Subtotal: -
On Sale
PROX Gasket Kit - Complete - Kawasaki 34.4027
PROX
MSRP: $63.15Now: $54.00Was: $63.15PROX Gasket Kit - Complete - Kawasaki09345588- SKU:
- 09345588
- Availability:
- Ships Same Business Day
- Weight:
- 0.25 LBS
- ENGINE TYPE:
- 2-STROKE
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- COMPLETE
- PRODUCT NAME:
- GASKET KIT
- UNITS:
- KIT
MSRP: $63.15Now: $54.00Was: $63.15Qty in Cart: 0Quantity:Price:MSRP: $63.15Now: $54.00Was: $63.15Subtotal: -
On Sale
PROX Gasket Kit - Complete - Kawasaki 34.4218
PROX
MSRP: $94.95Now: $81.00Was: $94.95PROX Gasket Kit - Complete - Kawasaki09345597- SKU:
- 09345597
- Availability:
- Ships Same Business Day
- Weight:
- 0.30 LBS
- UNITS:
- KIT
- PRODUCT NAME:
- GASKET KIT
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- COMPLETE
- ENGINE TYPE:
- 2-STROKE
MSRP: $94.95Now: $81.00Was: $94.95Qty in Cart: 0Quantity:Price:MSRP: $94.95Now: $81.00Was: $94.95Subtotal: -
On Sale
PROX Gasket Kit - Complete - Kawasaki 34.4223
PROX
MSRP: $99.95Now: $85.00Was: $99.95PROX Gasket Kit - Complete - Kawasaki09345599- SKU:
- 09345599
- Availability:
- Ships Same Business Day
- Weight:
- 0.30 LBS
- PRODUCT NAME:
- GASKET KIT
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- COMPLETE
- UNITS:
- KIT
- ENGINE TYPE:
- 2-STROKE
MSRP: $99.95Now: $85.00Was: $99.95Qty in Cart: 0Quantity:Price:MSRP: $99.95Now: $85.00Was: $99.95Subtotal: -
On Sale
PROX Gasket Kit - Complete - Kawasaki 34.4339
PROX
MSRP: $154.95Now: $132.00Was: $154.95PROX Gasket Kit - Complete - Kawasaki09345606- SKU:
- 09345606
- Availability:
- Ships Same Business Day
- Weight:
- 0.40 LBS
- ENGINE TYPE:
- 4-STROKE
- PRODUCT NAME:
- GASKET KIT
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- COMPLETE
- UNITS:
- KIT
MSRP: $154.95Now: $132.00Was: $154.95 -
On Sale
PROX Gasket Kit - Complete - KTM 34.6248
PROX
MSRP: $96.10Now: $82.00Was: $96.10PROX Gasket Kit - Complete - KTM09345621- SKU:
- 09345621
- Availability:
- Ships Same Business Day
- Weight:
- 0.40 LBS
- PRODUCT NAME:
- GASKET KIT
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- COMPLETE
- UNITS:
- KIT
- ENGINE TYPE:
- 2-STROKE
MSRP: $96.10Now: $82.00Was: $96.10Qty in Cart: 0Quantity:Price:MSRP: $96.10Now: $82.00Was: $96.10Subtotal: -
On Sale
PROX Gasket Kit - Complete - KTM 34.6340
PROX
MSRP: $94.95Now: $81.00Was: $94.95PROX Gasket Kit - Complete - KTM09345633- SKU:
- 09345633
- Availability:
- Ships Same Business Day
- Weight:
- 0.35 LBS
- RIDING STYLE:
- STREET
- ENGINE TYPE:
- 2-STROKE
- PRODUCT NAME:
- GASKET KIT
- TYPE:
- COMPLETE
- UNITS:
- KIT
MSRP: $94.95Now: $81.00Was: $94.95Qty in Cart: 0Quantity:Price:MSRP: $94.95Now: $81.00Was: $94.95Subtotal: -
On Sale
PROX Top End Gasket Set - Honda 35.1210
PROX
MSRP: $39.95Now: $34.00Was: $39.95PROX Top End Gasket Set - Honda09345656- SKU:
- 09345656
- Availability:
- Ships Same Business Day
- Weight:
- 0.10 LBS
- PRODUCT NAME:
- GASKET SET
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- TOP END
- UNITS:
- SET
MSRP: $39.95Now: $34.00Was: $39.95Qty in Cart: 0Quantity:Price:MSRP: $39.95Now: $34.00Was: $39.95Subtotal: -
On Sale
PROX Top End Gasket Set - Honda 35.1220
PROX
MSRP: $39.95Now: $34.00Was: $39.95PROX Top End Gasket Set - Honda09345658- SKU:
- 09345658
- Availability:
- Ships Same Business Day
- Weight:
- 0.10 LBS
- UNITS:
- SET
- PRODUCT NAME:
- GASKET SET
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- TOP END
MSRP: $39.95Now: $34.00Was: $39.95Qty in Cart: 0Quantity:Price:MSRP: $39.95Now: $34.00Was: $39.95Subtotal: -
On Sale
PROX Top End Gasket Set - Honda 35.1236
PROX
MSRP: $44.95Now: $38.00Was: $44.95PROX Top End Gasket Set - Honda09345664- SKU:
- 09345664
- Availability:
- Ships Same Business Day
- Weight:
- 0.10 LBS
- PRODUCT NAME:
- GASKET SET
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- TOP END
- UNITS:
- SET
MSRP: $44.95Now: $38.00Was: $44.95Qty in Cart: 0Quantity:Price:MSRP: $44.95Now: $38.00Was: $44.95Subtotal: -
On Sale
PROX Top End Gasket Set - Honda 35.1322
PROX
MSRP: $39.95Now: $34.00Was: $39.95PROX Top End Gasket Set - Honda09345669- SKU:
- 09345669
- Availability:
- Ships Same Business Day
- Weight:
- 0.10 LBS
- PRODUCT NAME:
- GASKET SET
- UNITS:
- SET
- TYPE:
- TOP END
- RIDING STYLE:
- OFF-ROAD
MSRP: $39.95Now: $34.00Was: $39.95Qty in Cart: 0Quantity:Price:MSRP: $39.95Now: $34.00Was: $39.95Subtotal: -
On Sale
PROX Piston Kit 01.1218.A3
PROX
MSRP: $105.95Now: $90.00Was: $105.95Manufactured in Japan and designed to be OEM replacement, Cast from a high-silicon-content aluminum alloy that meets or exceeds OEM specifications, then CNC-machined to extremely close tolerances, Pistons supplied in a kit package that includes rings,...PX4260C- SKU:
- PX4260C
- Availability:
- Ships Same Business Day
- Weight:
- 0.38 LBS
- PISTON DIAMETER METRIC:
- 53.96 MM
- PISTON MATERIAL:
- ALUMINUM ALLOY
- UNITS:
- EACH
- BORE SIZE METRIC:
- 53.96 MM
- PRODUCT NAME:
- PISTON KIT
- PISTON SIZE METRIC:
- STANDARD SIZE A
- RIDING STYLE:
- OFF-ROAD
MSRP: $105.95Now: $90.00Was: $105.95Qty in Cart: 0Quantity:Price:MSRP: $105.95Now: $90.00Was: $105.95Subtotal:
