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 Crankshaft Oil Seal Set - Beta 42.7220
PROX
MSRP: $22.95Now: $17.00Was: $22.95A complete crankshaft rebuild demands precision sealing to prevent oil leakage and maintain engine integrity. The PROX Crankshaft Oil Seal Set delivers OEM-specification components manufactured to...09351280- SKU:
- 09351280
- Availability:
- Ships Same Business Day
- Weight:
- 0.04 LBS
MSRP: $22.95Now: $17.00Was: $22.95 -
On Sale
PROX Crankshaft Oil Seal Set - Beta 42.7350
PROX
MSRP: $30.95Now: $25.00Was: $30.95A compromised crankshaft seal can lead to catastrophic oil loss and engine damage—especially under high RPM conditions where pressure spikes expose even minor leaks. The PROX Crankshaft Oil Seal Set...09351281- SKU:
- 09351281
- Availability:
- Ships Same Business Day
- Weight:
- 0.06 LBS
MSRP: $30.95Now: $25.00Was: $30.95 -
On Sale
PROX Connecting Rod Kit - Honda 03.1363
PROX
MSRP: $173.95Now: $141.00Was: $173.95A connecting rod kit is critical infrastructure for any high-performance Honda engine build—it directly transfers combustion forces from the piston to the crankshaft, making durability and precision...09230694- SKU:
- 09230694
- Availability:
- Ships Same Business Day
- Weight:
- 1.20 LBS
MSRP: $173.95Now: $141.00Was: $173.95 -
On Sale
PROX Connecting Rod Kit - Yamaha 03.2018
PROX
MSRP: $118.95Now: $93.00Was: $118.95A connecting rod failure mid-race or mid-rebuild can derail your entire engine program. The PROX Connecting Rod Kit for Yamaha engines delivers the dimensional precision and material strength needed...09230695- SKU:
- 09230695
- Availability:
- Ships Same Business Day
- Weight:
- 0.50 LBS
MSRP: $118.95Now: $93.00Was: $118.95 -
On Sale
PROX Connecting Rod Kit - Yamaha 03.2232
PROX
MSRP: $132.95Now: $102.00Was: $132.95A connecting rod kit is critical for maintaining engine integrity and performance—it directly transfers combustion forces from your pistons to the crankshaft, and a worn or damaged rod can cause...09230696- SKU:
- 09230696
- Availability:
- Ships Same Business Day
- Weight:
- 0.80 LBS
MSRP: $132.95Now: $102.00Was: $132.95 -
On Sale
PROX Connecting Rod Kit - Gas Gas | Yamaha 03.2432
PROX
MSRP: $183.95Now: $150.00Was: $183.95A connecting rod is critical to engine reliability—it directly transfers combustion force from the piston to the crankshaft under extreme stress and temperature. PROX's double-forged construction...09230697- SKU:
- 09230697
- Availability:
- Ships Same Business Day
- Weight:
- 1.35 LBS
MSRP: $183.95Now: $150.00Was: $183.95 -
On Sale
PROX Connecting Rod Kit - Husaberg | Husqvarna | KTM 03.6333
PROX
MSRP: $232.95Now: $195.00Was: $232.95A connecting rod is the critical link between your piston and crankshaft—any weakness here directly impacts power delivery, reliability, and engine longevity. The PROX Connecting Rod Kit for...09230699- SKU:
- 09230699
- Availability:
- Ships Same Business Day
- Weight:
- 1.20 LBS
MSRP: $232.95Now: $195.00Was: $232.95 -
On Sale
PROX Connecting Rod Kit - Beta 03.7322
PROX
MSRP: $137.95Now: $110.00Was: $137.95A connecting rod is the critical link between your piston and crankshaft—any weakness here directly compromises power delivery and engine reliability. The PROX Connecting Rod Kit is engineered to OEM...09230702- SKU:
- 09230702
- Availability:
- Ships Same Business Day
- Weight:
- 1.11 LBS
MSRP: $137.95Now: $110.00Was: $137.95 -
On Sale
PROX Crankshaft Bearing/Seal Kit - Honda 23.CBS14005
PROX
MSRP: $138.95Now: $110.00Was: $138.95A worn crankshaft bearing or compromised seal will rapidly degrade engine performance and reliability. This ProX kit replaces all critical bearing and seal components in one complete package,...09240701- SKU:
- 09240701
- Availability:
- Ships Same Business Day
- Weight:
- 1.15 LBS
MSRP: $138.95Now: $110.00Was: $138.95 -
On Sale
PROX Crankshaft Bearing/Seal Kit - Kawasaki 23.CBS43051
PROX
MSRP: $106.95Now: $85.00Was: $106.95A crankshaft bearing and seal failure can sideline your engine and compromise reliability when you need it most. This PROX kit delivers OEM-specification components engineered to restore your...09240702- SKU:
- 09240702
- Availability:
- Ships Same Business Day
- Weight:
- 1.00 LBS
MSRP: $106.95Now: $85.00Was: $106.95Qty in Cart: 0Quantity:Price:MSRP: $106.95Now: $85.00Was: $106.95Subtotal: -
On Sale
PROX Crankshaft Bearing/Seal Kit - KTM 23.CBS60001
PROX
MSRP: $38.95Now: $31.00Was: $38.95A properly sealed crankshaft is fundamental to engine longevity—compromised bearings and worn seals lead to oil starvation and contamination that cascade into catastrophic failure. This ProX kit...09240703- SKU:
- 09240703
- Availability:
- Ships Same Business Day
- Weight:
- 0.30 LBS
MSRP: $38.95Now: $31.00Was: $38.95 -
On Sale
PROX Crankshaft Bearing/Seal Kit - KTM 23.CBS60009
PROX
MSRP: $41.95Now: $34.00Was: $41.95A worn or damaged crankshaft bearing and seal assembly will compromise engine integrity, reduce performance, and risk catastrophic failure. The PROX Crankshaft Bearing/Seal Kit delivers...09240704- SKU:
- 09240704
- Availability:
- Ships Same Business Day
- Weight:
- 0.40 LBS
MSRP: $41.95Now: $34.00Was: $41.95 -
On Sale
PROX Crankshaft Bearing/Seal Kit - Husaberg/Husqvarna/KTM 23.CBS63013
PROX
MSRP: $187.95Now: $150.00Was: $187.95A compromised crankshaft bearing or seal will quickly degrade engine performance and lead to catastrophic internal damage. The PROX Crankshaft Bearing/Seal Kit supplies all necessary components to...09240705- SKU:
- 09240705
- Availability:
- Ships Same Business Day
- Weight:
- 0.70 LBS
MSRP: $187.95Now: $150.00Was: $187.95 -
On Sale
PROX Crankshaft Bearing/Seal Kit - Husqvarna/KTM 23.CBS63016
PROX
MSRP: $180.95Now: $144.00Was: $180.95Crankshaft bearing and seal failure can compromise engine integrity and sideline your machine at critical moments. This ProX kit delivers OEM-specification components engineered for reliability,...09240706- SKU:
- 09240706
- Availability:
- Ships Same Business Day
- Weight:
- 1.20 LBS
MSRP: $180.95Now: $144.00Was: $180.95 -
On Sale
PROX Crankshaft Bearing/Seal Kit - KTM 23.CBS64007
PROX
MSRP: $169.95Now: $136.00Was: $169.95A worn crankshaft bearing or degraded seal compromises engine reliability and can lead to catastrophic damage if left unaddressed. The PROX Crankshaft Bearing/Seal Kit restores OEM-specification...09240708- SKU:
- 09240708
- Availability:
- Ships Same Business Day
- Weight:
- 0.60 LBS
MSRP: $169.95Now: $136.00Was: $169.95 -
On Sale
PROX Crankshaft Bearing/Seal Kit - Husaberg/Husqvarna/KTM 23.CBS64012
PROX
MSRP: $95.95Now: $76.00Was: $95.95A crankshaft bearing and seal kit is essential maintenance for keeping your engine reliable through demanding riding conditions. ProX's OEM-specification design ensures your crankshaft operates with...09240709- SKU:
- 09240709
- Availability:
- Ships Same Business Day
- Weight:
- 0.90 LBS
MSRP: $95.95Now: $76.00Was: $95.95 -
On Sale
PROX Crankshaft Bearing/Seal Kit - Gas-Gas/Husqvarna/KTM 23.CBS64016
PROX
MSRP: $169.95Now: $136.00Was: $169.95A crankshaft bearing and seal kit is essential maintenance for keeping your two-stroke engine running at peak performance and reliability. Over time, factory bearings wear and seals degrade, allowing...09240710- SKU:
- 09240710
- Availability:
- Ships Same Business Day
- Weight:
- 1.00 LBS
MSRP: $169.95Now: $136.00Was: $169.95 -
On Sale
PROX Crankshaft Bearing/Seal Kit - Beta 23.CBS73013
PROX
MSRP: $73.95Now: $59.00Was: $73.95Engine longevity depends on precision bearing and seal integrity—factory-spec replacements prevent premature wear, oil leakage, and catastrophic failure. The PROX 23.CBS73013 kit delivers OEM-quality...09240711- SKU:
- 09240711
- Availability:
- Ships Same Business Day
- Weight:
- 0.70 LBS
MSRP: $73.95Now: $59.00Was: $73.95 -
On Sale
PROX Crankshaft Bearing/Seal Kit - Beta 23.CBS73022
PROX
MSRP: $123.95Now: $99.00Was: $123.95Crankshaft bearing and seal failure doesn't just sideline your engine—it can cause catastrophic internal damage that costs thousands to repair. The PROX Crankshaft Bearing/Seal Kit (Beta 23.CBS73022)...09240712- SKU:
- 09240712
- Availability:
- Ships Same Business Day
- Weight:
- 1.00 LBS
MSRP: $123.95Now: $99.00Was: $123.95 -
On Sale
PROX Crankshaft Bearing/Seal Kit - Beta 23.CBS73050
PROX
MSRP: $106.95Now: $85.00Was: $106.95A crankshaft bearing and seal failure can sideline your engine when you can least afford it. The PROX 23.CBS73050 kit delivers OEM-spec replacement bearings and seals manufactured to exact factory...09240713- SKU:
- 09240713
- Availability:
- Ships Same Business Day
- Weight:
- 1.36 LBS
MSRP: $106.95Now: $85.00Was: $106.95
