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 Gasket Kit - Complete 34.6216
PROX
$126.95A quality gasket kit is the foundation of engine reliability—sealing critical surfaces that prevent oil leaks, coolant loss, and combustion blow-by that compromise performance and longevity. PROX's complete gasket kit eliminates the guesswork of sourcing...09346685- SKU:
- 09346685
- Availability:
- Ships Same Business Day
- Weight:
- 0.10 LBS
- RIDING STYLE:
- STREET
- UNITS:
- KIT
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- COMPLETE
- ENGINE TYPE:
- 2-STROKE
- PRODUCT NAME:
- GASKET KIT
$126.95 -
PROX Crank Seal Kit - CRF250R 42.1402
PROX
$22.95A compromised crank seal accelerates wear on your bottom end and invites contamination into critical bearing surfaces—a direct path to catastrophic engine failure. This PROX kit delivers OEM-quality seals engineered for the CRF250R, ensuring a complete,...09350070- SKU:
- 09350070
- Availability:
- Ships Same Business Day
- Weight:
- 0.11 LBS
- APPLICATION:
- CRANKSHAFT
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- TYPE:
- OIL
- PRODUCT NAME:
- SEAL
$22.95 -
PROX Crank Seal Kit - YZ125 42.2225
PROX
$16.95A worn or leaking crank seal will compromise engine compression and allow contamination into your bottom end—both costly problems that compromise reliability and performance. The PROX Crank Seal Kit includes every seal required for a complete crank...09350071- SKU:
- 09350071
- Availability:
- Ships Same Business Day
- Weight:
- 0.10 LBS
- TYPE:
- OIL
- APPLICATION:
- CRANKSHAFT
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- PRODUCT NAME:
- SEAL
$16.95 -
PROX Crank Seal Kit - RM250 42.3323
PROX
$29.95A worn crankshaft seal can silently undermine engine reliability, leading to oil leakage and costly damage that sidelined racers can't afford. The PROX Crank Seal Kit RM250 delivers OEM-quality seals in one complete package, eliminating guesswork during...09350073- SKU:
- 09350073
- Availability:
- Ships Same Business Day
- Weight:
- 0.10 LBS
- APPLICATION:
- CRANKSHAFT
- TYPE:
- OIL
- UNITS:
- KIT
- PRODUCT NAME:
- SEAL
- RIDING STYLE:
- OFF-ROAD
$29.95Qty in Cart: 0Quantity:Price:$29.95Subtotal: -
PROX Water Pump Rebuild Kit - Honda 57.1015
PROX
$54.95A failing water pump compromises engine cooling efficiency and risks catastrophic overheating—especially under high-RPM racing conditions. The PROX Water Pump Rebuild Kit restores OEM performance and reliability with precision-engineered internal...09346984- SKU:
- 09346984
- Availability:
- Ships Same Business Day
- Weight:
- 0.10 LBS
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- WATER PUMP
- UNITS:
- KIT
- PRODUCT NAME:
- REPAIR KIT
$54.95Qty in Cart: 0Quantity:Price:$54.95Subtotal: -
PROX Water Pump Rebuild Kit - Honda 57.1219
PROX
$41.95A failing water pump can silently destroy your engine's thermal management, leading to overheating, head gasket failure, and catastrophic damage that costs thousands to repair. The PROX Water Pump Rebuild Kit gives you a complete, factory-quality...09346985- SKU:
- 09346985
- Availability:
- Ships Same Business Day
- Weight:
- 0.15 LBS
- PRODUCT NAME:
- REPAIR KIT
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- TYPE:
- WATER PUMP
$41.95Qty in Cart: 0Quantity:Price:$41.95Subtotal: -
PROX Water Pump Rebuild Kit - Honda 57.1227
PROX
$36.95A failing water pump can compromise engine cooling efficiency and lead to catastrophic overheating—especially under racing conditions or sustained high-performance driving. The PROX Water Pump Rebuild Kit for Honda delivers OEM-equivalent components at a...09346987- SKU:
- 09346987
- Availability:
- Ships Same Business Day
- Weight:
- 0.10 LBS
- PRODUCT NAME:
- REPAIR KIT
- TYPE:
- WATER PUMP
- UNITS:
- KIT
- RIDING STYLE:
- OFF-ROAD
$36.95 -
PROX Water Pump Rebuild Kit - Honda 57.1319
PROX
$41.95A failing water pump compromises engine cooling efficiency and risks catastrophic overheating—especially critical under racing conditions or sustained high-performance driving. The PROX Water Pump Rebuild Kit restores OEM-level cooling performance...09346989- SKU:
- 09346989
- Availability:
- Ships Same Business Day
- Weight:
- 0.10 LBS
- PRODUCT NAME:
- REPAIR KIT
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- WATER PUMP
- UNITS:
- KIT
$41.95 -
PROX Water Pump Rebuild Kit - Honda 57.1321
PROX
$54.95A failing water pump can compromise engine cooling and lead to catastrophic overheating—especially under racing conditions or sustained high-performance driving. The PROX 57.1321 rebuild kit restores your Honda's cooling system to factory specifications...09346990- SKU:
- 09346990
- Availability:
- Ships Same Business Day
- Weight:
- 0.20 LBS
- PRODUCT NAME:
- REPAIR KIT
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- WATER PUMP
- UNITS:
- KIT
$54.95Qty in Cart: 0Quantity:Price:$54.95Subtotal: -
PROX Water Pump Rebuild Kit - Honda 57.1322
PROX
$36.95A failing water pump can lead to catastrophic engine overheating and costly rebuilds. Rather than replacing the entire assembly, the PROX Water Pump Rebuild Kit gives you OEM-quality components at a fraction of the cost, restoring cooling system...09346991- SKU:
- 09346991
- Availability:
- Ships Same Business Day
- Weight:
- 0.15 LBS
- PRODUCT NAME:
- REPAIR KIT
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- WATER PUMP
- UNITS:
- KIT
$36.95Qty in Cart: 0Quantity:Price:$36.95Subtotal: -
PROX Water Pump Rebuild Kit - Honda 57.1324
PROX
$36.95A failing water pump is one of the most common causes of unexpected engine damage and costly downtime. The PROX Water Pump Rebuild Kit gives you a cost-effective way to restore your Honda's cooling system to OEM specifications without replacing the...09346992- SKU:
- 09346992
- Availability:
- Ships Same Business Day
- Weight:
- 0.10 LBS
- PRODUCT NAME:
- REPAIR KIT
- TYPE:
- WATER PUMP
- UNITS:
- KIT
- RIDING STYLE:
- OFF-ROAD
$36.95Qty in Cart: 0Quantity:Price:$36.95Subtotal: -
PROX Water Pump Rebuild Kit - Honda 57.1425
PROX
$62.95A failing water pump can quickly compromise engine cooling and lead to catastrophic overheating—especially under racing conditions or sustained high-performance driving. The PROX Water Pump Rebuild Kit for Honda gives you a cost-effective way to restore...09346995- SKU:
- 09346995
- Availability:
- Ships Same Business Day
- Weight:
- 0.25 LBS
- PRODUCT NAME:
- REPAIR KIT
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- TYPE:
- WATER PUMP
$62.95 -
PROX Water Pump Rebuild Kit - Honda 57.1429
PROX
$52.95Your Honda's cooling system depends on a properly functioning water pump—neglect it, and you're risking catastrophic engine failure. The PROX Water Pump Rebuild Kit gives you OEM-quality seals, gaskets, and components to restore your pump to factory...09346999- SKU:
- 09346999
- Availability:
- Ships Same Business Day
- Weight:
- 0.10 LBS
- PRODUCT NAME:
- REPAIR KIT
- TYPE:
- WATER PUMP
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
$52.95 -
PROX Water Pump Rebuild Kit - Yamaha 57.2114
PROX
$36.95A failing water pump compromises engine cooling efficiency and risks catastrophic overheating during high-performance operation. The PROX Water Pump Rebuild Kit restores OEM cooling capacity with precision-engineered internals, eliminating leaks and...09347004- SKU:
- 09347004
- Availability:
- Ships Same Business Day
- Weight:
- 0.15 LBS
- PRODUCT NAME:
- REPAIR KIT
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- WATER PUMP
- UNITS:
- KIT
$36.95Qty in Cart: 0Quantity:Price:$36.95Subtotal: -
PROX Water Pump Rebuild Kit - Yamaha 57.2122
PROX
$36.95A failing water pump compromises engine cooling efficiency and risks catastrophic overheating—especially critical under racing conditions or sustained high-performance driving. The PROX 57.2122 Rebuild Kit restores your Yamaha water pump to OEM...09347005- SKU:
- 09347005
- Availability:
- Ships Same Business Day
- Weight:
- 0.10 LBS
- PRODUCT NAME:
- REPAIR KIT
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- WATER PUMP
- UNITS:
- KIT
$36.95 -
PROX Water Pump Rebuild Kit - Yamaha 57.2218
PROX
$36.95A worn water pump compromises cooling efficiency and risks catastrophic engine damage—especially critical in high-performance applications where thermal management directly impacts reliability and power output. The PROX Water Pump Rebuild Kit restores...09347006- SKU:
- 09347006
- 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 - Yamaha 57.2225
PROX
$36.95Water pump failure can leave you stranded and cause catastrophic engine damage from overheating. The PROX Water Pump Rebuild Kit gives you factory-quality internal components to restore cooling system integrity without replacing the entire pump assembly...09347007- SKU:
- 09347007
- Availability:
- Ships Same Business Day
- Weight:
- 0.10 LBS
- RIDING STYLE:
- OFF-ROAD
- PRODUCT NAME:
- REPAIR KIT
- TYPE:
- WATER PUMP
- UNITS:
- KIT
$36.95 -
PROX Water Pump Rebuild Kit - Yamaha 57.2318
PROX
$44.95A failing water pump can compromise your engine's thermal stability and lead to catastrophic overheating—especially under racing conditions or extended high-load operation. The PROX Water Pump Rebuild Kit gives you OEM-equivalent seals, gaskets, and...09347009- SKU:
- 09347009
- Availability:
- Ships Same Business Day
- Weight:
- 0.20 LBS
- PRODUCT NAME:
- REPAIR KIT
- TYPE:
- WATER PUMP
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
$44.95 -
PROX Water Pump Rebuild Kit - Yamaha 57.2319
PROX
$36.95A failing water pump compromises your engine's cooling efficiency, risking catastrophic overheating during high-performance operation. The PROX 57.2319 Rebuild Kit lets you restore your Yamaha water pump to OEM specifications without the cost of a...09347010- SKU:
- 09347010
- Availability:
- Ships Same Business Day
- Weight:
- 0.10 LBS
- PRODUCT NAME:
- REPAIR KIT
- TYPE:
- WATER PUMP
- UNITS:
- KIT
- RIDING STYLE:
- OFF-ROAD
$36.95 -
PROX Water Pump Rebuild Kit - Yamaha 57.2320
PROX
$34.95A failing water pump compromises engine cooling efficiency and risks catastrophic overheating—especially under racing conditions or sustained high-RPM operation. The PROX Water Pump Rebuild Kit for Yamaha gives you OEM-equivalent cooling performance with...09347011- SKU:
- 09347011
- Availability:
- Ships Same Business Day
- Weight:
- 0.03 LBS
- PRODUCT NAME:
- REPAIR KIT
- TYPE:
- WATER PUMP
- ENGINE TYPE:
- 4-STROKE
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
$34.95Qty in Cart: 0Quantity:Price:$34.95Subtotal:
