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
-
PROX Crank Bearing and Seal Kit 23.CBS43004
PROX
$91.95A complete crankshaft bearing and seal kit is essential for any rebuild—worn bearings compromise power delivery and accelerate wear on adjacent components. This Pro X kit supplies everything needed...09240356- SKU:
- 09240356
- Availability:
- Ships Same Business Day
- Weight:
- 0.95 LBS
- UNITS:
- KIT
- APPLICATION:
- CRANKSHAFT
- RIDING STYLE:
- OFF-ROAD
- PRODUCT NAME:
- BEARING AND SEAL KIT
- STYLE:
- 4-STROKE
- TYPE:
- BALL
$91.95 -
PROX Crank Bearing and Seal Kit 23.CBS43087
PROX
$80.95A crankshaft rebuild demands precision—and compromising on bearing and seal quality is a guaranteed path to premature failure and costly downtime. The PROX Crank Bearing and Seal Kit 23.CBS43087...09240357- SKU:
- 09240357
- Availability:
- Ships Same Business Day
- Weight:
- 1.50 LBS
- APPLICATION:
- CRANKSHAFT
- TYPE:
- BALL
- PRODUCT NAME:
- BEARING AND SEAL KIT
- UNITS:
- KIT
- RIDING STYLE:
- OFF-ROAD
- STYLE:
- 2-STROKE
$80.95 -
PROX Crank Bearing and Seal Kit 23.CBS45088
PROX
$70.95A complete crank bearing and seal replacement is essential maintenance for any high-performance engine, preventing catastrophic failure and restoring proper clearances after extended use or rebuild...09240359- SKU:
- 09240359
- Availability:
- Ships Same Business Day
- Weight:
- 1.75 LBS
- APPLICATION:
- CRANKSHAFT
- TYPE:
- BALL
- PRODUCT NAME:
- BEARING AND SEAL KIT
- RIDING STYLE:
- OFF-ROAD
- STYLE:
- 2-STROKE
- UNITS:
- KIT
$70.95 -
PROX Crank Bearing and Seal Kit 23.CBS61009
PROX
$59.95A crankshaft rebuild demands precision—one compromised bearing or seal leads to catastrophic engine failure. The PROX Crank Bearing and Seal Kit 23.CBS61009 eliminates guesswork by delivering every...09240361- SKU:
- 09240361
- Availability:
- Ships Same Business Day
- Weight:
- 0.80 LBS
- APPLICATION:
- CRANKSHAFT
- PRODUCT NAME:
- BEARING AND SEAL KIT
- TYPE:
- BALL
- RIDING STYLE:
- OFF-ROAD
- STYLE:
- 2-STROKE
- UNITS:
- KIT
$59.95 -
PROX Crank Bearing and Seal Kit 23.CBS61097
PROX
$49.95A complete crank bearing and seal kit is essential for maintaining proper lubrication, reducing friction, and extending crankshaft life under high-stress conditions. Whether you're rebuilding after...09240362- SKU:
- 09240362
- Availability:
- Ships Same Business Day
- Weight:
- 0.80 LBS
- APPLICATION:
- CRANKSHAFT
- TYPE:
- BALL
- PRODUCT NAME:
- BEARING AND SEAL KIT
- RIDING STYLE:
- OFF-ROAD
- STYLE:
- 2-STROKE
- UNITS:
- KIT
$49.95Qty in Cart: 0Quantity:Price:$49.95Subtotal: -
PROX Crank Bearing and Seal Kit 23.CBS62001
PROX
$112.95A complete crankshaft bearing and seal replacement is critical for maintaining peak engine reliability and performance, especially if you're running high RPMs or preparing for competition. This Pro X...09240363- SKU:
- 09240363
- Availability:
- Ships Same Business Day
- Weight:
- 1.10 LBS
- PRODUCT NAME:
- BEARING AND SEAL KIT
- TYPE:
- BALL
- STYLE:
- 2-STROKE
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- APPLICATION:
- CRANKSHAFT
- RIDING STYLE:
- STREET
$112.95 -
PROX Crank Bearing and Seal Kit 23.CBS63004
PROX
$133.95A crankshaft bearing and seal failure can leave you stranded or worse—damage your entire engine. The PROX Crank Bearing and Seal Kit 23.CBS63004 gives you a complete, factory-spec replacement...09240365- SKU:
- 09240365
- Availability:
- Ships Same Business Day
- Weight:
- 1.33 LBS
- PRODUCT NAME:
- BEARING AND SEAL KIT
- TYPE:
- BALL
- STYLE:
- 2-STROKE
- APPLICATION:
- CRANKSHAFT
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- RIDING STYLE:
- STREET
$133.95 -
PROX Crank Bearing and Seal Kit 23.CBS63006
PROX
$149.95A quality crank bearing and seal kit is critical to engine reliability—worn or damaged bearings accelerate crankshaft wear and can lead to catastrophic engine failure. The PROX 23.CBS63006 delivers...09240366- SKU:
- 09240366
- Availability:
- Ships Same Business Day
- Weight:
- 1.05 LBS
- PRODUCT NAME:
- BEARING AND SEAL KIT
- STYLE:
- 4-STROKE
- TYPE:
- BALL
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- APPLICATION:
- CRANKSHAFT
$149.95Qty in Cart: 0Quantity:Price:$149.95Subtotal: -
PROX Connecting Rod Kit - KTM 125/150 SX 03.6226
PROX
$132.95A connecting rod is the critical link between your piston and crankshaft—when it fails, your engine fails. The PROX Connecting Rod Kit for KTM 125/150 SX delivers OEM-equivalent reliability with...09230471- SKU:
- 09230471
- Availability:
- Ships Same Business Day
- Weight:
- 0.80 LBS
- ENGINE TYPE:
- 2-STROKE
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- MATERIAL:
- FORGED
- MATERIAL:
- STEEL
- PRODUCT NAME:
- CONNECTING ROD KIT
$132.95 -
PROX Connecting Rod Kit - Kawasaki KX 250 F 03.4347
PROX
$236.95A connecting rod failure mid-race isn't just costly—it's catastrophic. The PROX Connecting Rod Kit for Kawasaki KX 250 F delivers the precision engineering and durability needed to withstand the...09230461- SKU:
- 09230461
- Availability:
- Ships Same Business Day
- Weight:
- 1.10 LBS
- UNITS:
- KIT
- MATERIAL:
- STEEL
- PRODUCT NAME:
- CONNECTING ROD KIT
- RIDING STYLE:
- OFF-ROAD
- ENGINE TYPE:
- 4-STROKE
- MATERIAL:
- FORGED
$236.95 -
PROX Connecting Rod Kit - Honda CRF250R 03.1348
PROX
$173.95A connecting rod failure mid-race costs you the event—and potentially your engine. The PROX Connecting Rod Kit for your CRF250R delivers OEM-spec durability with precision manufacturing that handles...09230561- SKU:
- 09230561
- Availability:
- Ships Same Business Day
- Weight:
- 1.25 LBS
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- PRODUCT NAME:
- CONNECTING ROD KIT
$173.95 -
PROX Connecting Rod Kit - KTM 85 SX/Husqvarna TC 85 03.6113
PROX
$110.95A connecting rod kit is critical for high-rpm reliability in two-stroke engines, where combustion forces demand precision-engineered components that can handle extreme load cycling. The PROX...09230331- SKU:
- 09230331
- Availability:
- Ships Same Business Day
- Weight:
- 0.45 LBS
- ENGINE TYPE:
- 2-STROKE
- MATERIAL:
- FORGED
- MATERIAL:
- STEEL
- PRODUCT NAME:
- CONNECTING ROD KIT
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
$110.95 -
PROX Connecting Rod 03.6029
PROX
$118.95A connecting rod is the critical link between your piston and crankshaft—any weakness here translates directly to lost power and reliability. The PROX 03.6029 arrives fully assembled with precision...09230277- SKU:
- 09230277
- Availability:
- Ships Same Business Day
- Weight:
- 0.56 LBS
- UNITS:
- EACH
- PRODUCT NAME:
- CONNECTING ROD KIT
- RIDING STYLE:
- OFF-ROAD
- ENGINE TYPE:
- 2-STROKE
- MATERIAL:
- FORGED STEEL
$118.95 -
PROX Connecting Rod Kit 03.4340
PROX
$165.95A connecting rod kit is the critical link between your crankshaft and piston—it must handle extreme loads, temperature swings, and RPM demands without flex or failure. The PROX Connecting Rod Kit 03...09230280- SKU:
- 09230280
- Availability:
- Ships Same Business Day
- Weight:
- 1.17 LBS
- UNITS:
- EACH
- ENGINE TYPE:
- 4-STROKE
- MATERIAL:
- FORGED STEEL
- PRODUCT NAME:
- CONNECTING ROD KIT
- RIDING STYLE:
- OFF-ROAD
$165.95Qty in Cart: 0Quantity:Price:$165.95Subtotal: -
PROX Connecting Rod Kit 03.6336
PROX
$165.95A connecting rod kit is critical to engine reliability, transferring power from your pistons to the crankshaft with precision and durability. The PROX 03.6336 comes fully assembled with all necessary...09230281- SKU:
- 09230281
- Availability:
- Ships Same Business Day
- Weight:
- 1.14 LBS
- PRODUCT NAME:
- CONNECTING ROD KIT
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- EACH
- MATERIAL:
- FORGED STEEL
- ENGINE TYPE:
- 4-STROKE
$165.95Qty in Cart: 0Quantity:Price:$165.95Subtotal: -
PROX Connecting Rod Kit 03.6340
PROX
$165.95A quality connecting rod is fundamental to engine reliability and power delivery—it's the critical link between your crankshaft and piston, transmitting combustion forces under extreme stress. The...09230282- SKU:
- 09230282
- Availability:
- Ships Same Business Day
- Weight:
- 1.22 LBS
- FEATURES:
- INCLUDES THRUST WASHERS
- MATERIAL:
- FORGED STEEL
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- EACH
- ENGINE TYPE:
- 4-STROKE
- PRODUCT NAME:
- CONNECTING ROD KIT
$165.95 -
PROX Connecting Rod Kit 03.6519
PROX
$199.95A connecting rod is the critical link between your crankshaft and piston—it must withstand immense forces while maintaining precise tolerances. The PROX Connecting Rod Kit 03.6519 comes fully...09230283- SKU:
- 09230283
- Availability:
- Ships Same Business Day
- Weight:
- 2.38 LBS
- UNITS:
- EACH
- ENGINE TYPE:
- 4-STROKE
- PRODUCT NAME:
- CONNECTING ROD KIT
- RIDING STYLE:
- OFF-ROAD
- MATERIAL:
- FORGED STEEL
$199.95Qty in Cart: 0Quantity:Price:$199.95Subtotal: -
PROX Connecting Rod Kit 03.1405
PROX
$183.95A connecting rod is the critical link between your piston and crankshaft—any flex, wear, or misalignment will rob you of power and reliability. The PROX Connecting Rod Kit 03.1405 delivers...09230239- SKU:
- 09230239
- Availability:
- Ships Same Business Day
- Weight:
- 1.71 LBS
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- EACH
- FEATURES:
- INCLUDES THRUST WASHERS
- MATERIAL:
- FORGED STEEL
- ENGINE TYPE:
- 4-STROKE
- PRODUCT NAME:
- CONNECTING ROD KIT
- RIDING STYLE:
- ATV
$183.95 -
PROX Connecting Rod Kit 03.6428
PROX
$188.95A connecting rod is the critical link between your crankshaft and piston—any wear, flex, or imbalance directly compromises engine efficiency and reliability. The PROX 03.6428 Kit delivers a complete,...09230246- SKU:
- 09230246
- Availability:
- Ships Same Business Day
- Weight:
- 1.77 LBS
- ENGINE TYPE:
- 4-STROKE
- MATERIAL:
- FORGED STEEL
- PRODUCT NAME:
- CONNECTING ROD KIT
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- EACH
- RIDING STYLE:
- STREET
$188.95 -
PROX Connecting Rod 03.3408
PROX
$175.95A connecting rod is the critical link between your crankshaft and piston—any weakness here compromises power delivery and engine reliability. The PROX 03.3408 is engineered for sustained high-RPM...09230250- SKU:
- 09230250
- Availability:
- Ships Same Business Day
- Weight:
- 1.58 LBS
- UNITS:
- EACH
- PRODUCT NAME:
- CONNECTING ROD KIT
- RIDING STYLE:
- OFF-ROAD
- ENGINE TYPE:
- 4-STROKE
- MATERIAL:
- FORGED STEEL
$175.95Qty in Cart: 0Quantity:Price:$175.95Subtotal:
