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 components in a complete package, restoring full cooling...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 reliability and longevity. The PROX Water Pump Rebuild...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 of replacement cost, restoring reliable thermal...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 replacement components to restore cooling system integrity...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 management, eliminating seal degradation and internal...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
$54.95 -
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 OEM-equivalent performance and reliability at a fraction of...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 Pump Rebuild Kit 57.6314 restores your pump to OEM...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, cost-effective solution to restore your pump to OEM performance...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 longevity. This PROX rebuild kit gives you OEM-quality...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 surfaces across your entire engine block, ensuring...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 and reliability. The PROX Gasket Kit - Complete delivers...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
$130.95 -
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 delivers OEM-equivalent sealing performance with...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 compression loss and oil weeping that compromises both...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 maintaining combustion chamber integrity. Whether...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 Yamaha delivers factory-spec sealing integrity with...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 sustained track duty, PROX's engineered gasket...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 performance and reliability. The PROX 35.2419 delivers...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 replacing worn gaskets, using OEM-equivalent gaskets...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 top-end sealing with OEM-equivalent materials and...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 set restores proper sealing without guesswork, ensuring...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
