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 Crank Bearing and Seal Kit 23.CBS42088
PROX
$70.95A properly sealed and supported crankshaft is foundational to engine reliability and consistent power delivery. This Pro X bearing and seal kit eliminates the guesswork by providing all necessary...09240352- SKU:
- 09240352
- Availability:
- Ships Same Business Day
- Weight:
- 1.00 LBS
- RIDING STYLE:
- OFF-ROAD
- STYLE:
- 2-STROKE
- UNITS:
- KIT
- TYPE:
- BALL
- PRODUCT NAME:
- BEARING AND SEAL KIT
- APPLICATION:
- CRANKSHAFT
$70.95 -
PROX Crank Bearing and Seal Kit 23.CBS42092
PROX
$70.95A crank bearing and seal kit is essential maintenance for any serious engine build—worn bearings compromise crankshaft stability and can cascade into catastrophic failure. This PROX kit delivers...09240353- SKU:
- 09240353
- Availability:
- Ships Same Business Day
- Weight:
- 1.15 LBS
- UNITS:
- KIT
- RIDING STYLE:
- STREET
- STYLE:
- 2-STROKE
- APPLICATION:
- CRANKSHAFT
- RIDING STYLE:
- OFF-ROAD
- PRODUCT NAME:
- BEARING AND SEAL KIT
- TYPE:
- BALL
$70.95 -
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.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 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 03.6340
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 03.1405
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 03.1315
PROX
$132.95A 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 03.1315 is...09230125- SKU:
- 09230125
- Availability:
- Ships Same Business Day
- Weight:
- 1.08 LBS
- ENGINE TYPE:
- 2-STROKE
- MATERIAL:
- FORGED STEEL
- RIDING STYLE:
- OFF-ROAD
- PRODUCT NAME:
- CONNECTING ROD KIT
- RIDING STYLE:
- ATV
- UNITS:
- EACH
$132.95 -
PROX Connecting Rod 03.1334
PROX
$173.95A connecting rod is the critical link between your piston and crankshaft—any weakness here compromises power transfer and engine reliability. The PROX 03.1334 arrives as a complete assembly,...09230127- SKU:
- 09230127
- Availability:
- Ships Same Business Day
- Weight:
- 1.15 LBS
- ENGINE TYPE:
- 4-STROKE
- MATERIAL:
- FORGED STEEL
- PRODUCT NAME:
- CONNECTING ROD KIT
- RIDING STYLE:
- OFF-ROAD
- FEATURES:
- INCLUDES THRUST WASHERS
- UNITS:
- EACH
$173.95 -
PROX Connecting Rod 03.6220
PROX
$132.95A connecting rod is the critical link between your crankshaft and piston—responsible for transmitting combustion forces and managing the repetitive stress of high-RPM operation. The PROX Connecting...09230128- SKU:
- 09230128
- Availability:
- Ships Same Business Day
- Weight:
- 0.79 LBS
- ENGINE TYPE:
- 2-STROKE
- MATERIAL:
- FORGED STEEL
- PRODUCT NAME:
- CONNECTING ROD KIT
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- EACH
$132.95 -
PROX Connecting Rod 03.4309
PROX
$132.95A connecting rod is the critical link between your crankshaft and piston—any flex, wear, or imbalance directly translates to power loss and reliability issues. The PROX 03.4309 is a complete,...09230131- SKU:
- 09230131
- Availability:
- Ships Same Business Day
- Weight:
- 1.12 LBS
- ENGINE TYPE:
- 2-STROKE
- PRODUCT NAME:
- CONNECTING ROD KIT
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- EACH
- MATERIAL:
- FORGED STEEL
$132.95
