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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PROX Water Pump Rebuild Kit - Kawasaki 57.4329
PROX
$41.95A failing water pump compromises your engine's cooling system, risking catastrophic overheating during high-performance operation. The PROX Water Pump Rebuild Kit for Kawasaki delivers OEM-quality...09347054- SKU:
- 09347054
- Availability:
- Ships Same Business Day
- Weight:
- 0.25 LBS
- PRODUCT NAME:
- REPAIR KIT
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- WATER PUMP
- UNITS:
- KIT
$41.95 -
PROX Water Pump Rebuild Kit - Kawasaki 57.4426
PROX
$36.95A failing water pump compromises engine cooling efficiency and risks catastrophic overheating—especially critical in high-performance Kawasaki applications where thermal management directly impacts...09347058- SKU:
- 09347058
- Availability:
- Ships Same Business Day
- Weight:
- 0.10 LBS
- TYPE:
- WATER PUMP
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- PRODUCT NAME:
- REPAIR KIT
$36.95 -
PROX Water Pump Rebuild Kit - Kawasaki 57.4518
PROX
$46.95A failing water pump compromises your engine's cooling system and puts your bike at risk of catastrophic overheating. The PROX Water Pump Rebuild Kit gives you OEM-equivalent components at a fraction...09347061- SKU:
- 09347061
- Availability:
- Ships Same Business Day
- Weight:
- 0.15 LBS
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- WATER PUMP
- UNITS:
- KIT
- PRODUCT NAME:
- REPAIR KIT
$46.95 -
PROX Water Pump Rebuild Kit - KTM 57.6018
PROX
$59.95Water pump failure is a silent killer in high-performance engines—once internal seals degrade, coolant bypass and overheating follow quickly. The PROX Water Pump Rebuild Kit gives you OEM-quality...09347063- SKU:
- 09347063
- Availability:
- Ships Same Business Day
- Weight:
- 0.15 LBS
- UNITS:
- KIT
- PRODUCT NAME:
- REPAIR KIT
- TYPE:
- WATER PUMP
- RIDING STYLE:
- OFF-ROAD
$59.95Qty in Cart: 0Quantity:Price:$59.95Subtotal: -
PROX Water Pump Rebuild Kit - KTM 57.6021
PROX
$54.95A failing water pump compromises engine cooling efficiency and risks catastrophic overheating during high-performance riding. The PROX Water Pump Rebuild Kit restores OEM-spec flow rates and thermal...09347064- SKU:
- 09347064
- Availability:
- Ships Same Business Day
- Weight:
- 0.10 LBS
- PRODUCT NAME:
- REPAIR KIT
- TYPE:
- WATER PUMP
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
$54.95Qty in Cart: 0Quantity:Price:$54.95Subtotal: -
PROX Water Pump Rebuild Kit - KTM 57.6218
PROX
$46.95A failing water pump doesn't just compromise cooling efficiency—it puts your engine at serious risk of overheating and catastrophic damage. The PROX Water Pump Rebuild Kit for KTM gives you...09347070- SKU:
- 09347070
- Availability:
- Ships Same Business Day
- Weight:
- 0.10 LBS
- TYPE:
- WATER PUMP
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- PRODUCT NAME:
- REPAIR KIT
$46.95 -
PROX Water Pump Rebuild Kit 57.6314
PROX
$62.95A failing water pump can compromise engine cooling efficiency and lead to catastrophic overheating—especially critical under racing conditions or sustained high-performance driving. The PROX Water...09347071- SKU:
- 09347071
- Availability:
- Ships Same Business Day
- Weight:
- 0.10 LBS
- PRODUCT NAME:
- REPAIR KIT
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- WATER PUMP
- UNITS:
- KIT
$62.95 -
PROX Water Pump Rebuild Kit 57.6322
PROX
$36.95A failing water pump doesn't just compromise cooling efficiency—it risks catastrophic engine damage and costly downtime. The PROX Water Pump Rebuild Kit 57.6322 gives you a straightforward,...09347075- SKU:
- 09347075
- Availability:
- Ships Same Business Day
- Weight:
- 0.12 LBS
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- TYPE:
- WATER PUMP
- PRODUCT NAME:
- REPAIR KIT
$36.95 -
PROX Water Pump Rebuild Kit 57.6429
PROX
$49.95A failing water pump compromises cooling efficiency and risks catastrophic engine damage—especially critical in high-performance applications where heat management directly impacts reliability and...09347081- SKU:
- 09347081
- Availability:
- Ships Same Business Day
- Weight:
- 0.10 LBS
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- TYPE:
- WATER PUMP
- PRODUCT NAME:
- REPAIR KIT
$49.95Qty in Cart: 0Quantity:Price:$49.95Subtotal: -
PROX Gasket Kit - Complete 34.3180
PROX
$69.95A complete gasket kit is essential for any engine rebuild or overhaul—sealing failures lead to oil leaks, coolant loss, and compromised performance. The PROX 34.3180 delivers factory-spec sealing...09347102- SKU:
- 09347102
- Availability:
- Ships Same Business Day
- Weight:
- 0.30 LBS
- TYPE:
- COMPLETE
- UNITS:
- KIT
- ENGINE TYPE:
- 2-STROKE
- PRODUCT NAME:
- GASKET KIT
- RIDING STYLE:
- ATV
$69.95 -
PROX Gasket Kit - Complete 34.6316
PROX
$130.95A complete gasket kit is essential maintenance for any serious engine build or rebuild—proper sealing prevents oil leaks, coolant seepage, and combustion chamber bypass that compromise performance...09347105- SKU:
- 09347105
- Availability:
- Ships Same Business Day
- Weight:
- 0.50 LBS
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- COMPLETE
- UNITS:
- KIT
- ENGINE TYPE:
- 4-STROKE
- PRODUCT NAME:
- GASKET KIT
$130.95Qty in Cart: 0Quantity:Price:$130.95Subtotal: -
PROX Top End Gasket Set - Honda 35.1417
PROX
$84.95A worn or damaged top end gasket set compromises cylinder head seal integrity, leading to coolant leaks, oil seepage, and potential combustion gas blow-by. The PROX Top End Gasket Set for Honda...09347110- SKU:
- 09347110
- Availability:
- Ships Same Business Day
- Weight:
- 0.10 LBS
- UNITS:
- SET
- PRODUCT NAME:
- GASKET SET
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- TOP END
$84.95 -
PROX Top End Gasket Set - Honda 35.1613
PROX
$67.95A properly sealed top end is non-negotiable for engine reliability and performance consistency. The PROX Top End Gasket Set (35.1613) delivers OEM-grade sealing for Honda applications, preventing...09347117- SKU:
- 09347117
- Availability:
- Ships Same Business Day
- Weight:
- 0.35 LBS
- PRODUCT NAME:
- GASKET SET
- UNITS:
- SET
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- TOP END
$67.95Qty in Cart: 0Quantity:Price:$67.95Subtotal: -
PROX Top End Gasket Set - Yamaha 35.2005
PROX
$22.95A properly sealed top end is non-negotiable for engine reliability and performance. The PROX Top End Gasket Set ensures a leak-free seal between critical engine components, preventing oil seepage and...09347119- SKU:
- 09347119
- Availability:
- Ships Same Business Day
- Weight:
- 0.05 LBS
- PRODUCT NAME:
- GASKET SET
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- TOP END
- UNITS:
- SET
$22.95 -
PROX Top End Gasket Set - Yamaha 35.2008
PROX
$25.95A failing top-end gasket set compromises compression, invites oil leaks, and tanks your engine's reliability—exactly what you can't afford mid-race or mid-season. The PROX Top End Gasket Set for...09347120- SKU:
- 09347120
- Availability:
- Ships Same Business Day
- Weight:
- 0.05 LBS
- PRODUCT NAME:
- GASKET SET
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- TOP END
- UNITS:
- SET
$25.95 -
PROX Top End Gasket Set - Yamaha 35.2129
PROX
$36.95A quality top-end gasket set is non-negotiable for maintaining compression integrity and preventing oil seepage in high-rev applications. Whether you're rebuilding after extended use or preparing for...09347123- SKU:
- 09347123
- Availability:
- Ships Same Business Day
- Weight:
- 0.05 LBS
- PRODUCT NAME:
- GASKET SET
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- TOP END
- UNITS:
- SET
$36.95 -
PROX Top End Gasket Set - Yamaha 35.2419
PROX
$78.95A quality top-end gasket set is non-negotiable for any engine rebuild or high-mileage refresh—it's your insurance policy against coolant leaks, oil seepage, and compression loss that compromise both...09347127- SKU:
- 09347127
- Availability:
- Ships Same Business Day
- Weight:
- 0.25 LBS
- ENGINE TYPE:
- 4-STROKE
- UNITS:
- SET
- PRODUCT NAME:
- GASKET SET
- TYPE:
- TOP END
- RIDING STYLE:
- OFF-ROAD
$78.95 -
PROX Top End Gasket Set - Yamaha 35.2424
PROX
$69.95A top-end gasket set is essential for maintaining reliable compression and preventing coolant or oil leaks in your engine's most critical sealing points. When you're rebuilding your Yamaha top end or...09347128- SKU:
- 09347128
- Availability:
- Ships Same Business Day
- Weight:
- 0.15 LBS
- UNITS:
- SET
- TYPE:
- TOP END
- PRODUCT NAME:
- GASKET SET
- RIDING STYLE:
- OFF-ROAD
$69.95Qty in Cart: 0Quantity:Price:$69.95Subtotal: -
PROX Top End Gasket Set - Yamaha 35.2434
PROX
$67.95A quality top-end gasket set is non-negotiable for engine reliability—whether you're rebuilding after a full teardown or replacing a failed gasket on the track. The PROX 35.2434 provides complete...09347129- SKU:
- 09347129
- Availability:
- Ships Same Business Day
- Weight:
- 0.15 LBS
- UNITS:
- SET
- RIDING STYLE:
- ATV
- TYPE:
- TOP END
- PRODUCT NAME:
- GASKET SET
$67.95 -
PROX Top End Gasket Set - Yamaha 35.2439
PROX
$72.95A worn or failed top end gasket set compromises compression, allows coolant and oil seepage, and undermines engine reliability during high-stress racing conditions. PROX's OEM-specification gasket...09347130- SKU:
- 09347130
- Availability:
- Ships Same Business Day
- Weight:
- 0.15 LBS
- UNITS:
- SET
- PRODUCT NAME:
- GASKET SET
- RIDING STYLE:
- ATV
- TYPE:
- TOP END
$72.95
