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.CBS21083
PROX
$59.95A crankshaft rebuild demands precision—substandard bearings and seals invite catastrophic failure and costly downtime. This PROX kit delivers OEM-exact specifications for reliable durability, whether you're running a stock bottom end or pairing it with a...09240310- SKU:
- 09240310
- Availability:
- Ships Same Business Day
- Weight:
- 0.45 LBS
- APPLICATION:
- CRANKSHAFT
- STYLE:
- 2-STROKE
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- PRODUCT NAME:
- BEARING AND SEAL KIT
- TYPE:
- BALL
$59.95 -
PROX Crank Bearing and Seal Kit 23.CBS21093
PROX
$36.95A compromised crankshaft bearing or seal can cascade into catastrophic engine failure—and downtime you can't afford. This PROX kit delivers OEM-spec replacements for both bearings and seals, ensuring your crank runs true and your engine stays sealed...09240311- SKU:
- 09240311
- Availability:
- Ships Same Business Day
- Weight:
- 0.80 LBS
- APPLICATION:
- CRANKSHAFT
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- STYLE:
- 2-STROKE
- PRODUCT NAME:
- BEARING AND SEAL KIT
- TYPE:
- BALL
$36.95 -
PROX Crank Bearing and Seal Kit 23.CBS22079
PROX
$39.95A crankshaft rebuild demands precision—any wear in the bearing surfaces or seal integrity compromises engine reliability and performance. The PROX Crank Bearing and Seal Kit 23.CBS22079 delivers OEM-specification components that restore your crankshaft...09240314- SKU:
- 09240314
- Availability:
- Ships Same Business Day
- Weight:
- 0.80 LBS
- RIDING STYLE:
- OFF-ROAD
- STYLE:
- 2-STROKE
- UNITS:
- KIT
- PRODUCT NAME:
- BEARING AND SEAL KIT
- APPLICATION:
- CRANKSHAFT
- TYPE:
- BALL
$39.95 -
PROX Crank Bearing and Seal Kit 23.CBS22080
PROX
$38.95A failed crank bearing or seal will sideline your engine faster than any mechanical failure—this PROX kit gives you everything needed for a complete, reliable rebuild without sourcing multiple components separately. Whether you're refreshing an OEM...09240315- SKU:
- 09240315
- Availability:
- Ships Same Business Day
- Weight:
- 0.80 LBS
- RIDING STYLE:
- OFF-ROAD
- STYLE:
- 2-STROKE
- UNITS:
- KIT
- APPLICATION:
- CRANKSHAFT
- TYPE:
- BALL
- PRODUCT NAME:
- BEARING AND SEAL KIT
$38.95 -
PROX Crank Bearing and Seal Kit 23.CBS22086
PROX
$70.95A worn crank bearing and seal kit compromises engine reliability and performance—exactly what you can't afford during a rebuild or overhaul. This PROX kit delivers OEM-specification components engineered to restore your crankshaft to factory tolerances,...09240316- SKU:
- 09240316
- Availability:
- Ships Same Business Day
- Weight:
- 1.00 LBS
- UNITS:
- KIT
- 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.CBS22098
PROX
$70.95A quality crank bearing and seal kit is non-negotiable for engine reliability and longevity—especially when you're pushing your machine to its limits. The PROX 23.CBS22098 delivers OEM-spec components that restore your crankshaft assembly to factory...09240318- SKU:
- 09240318
- Availability:
- Ships Same Business Day
- Weight:
- 0.95 LBS
- PRODUCT NAME:
- BEARING AND SEAL KIT
- STYLE:
- 2-STROKE
- TYPE:
- BALL
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- APPLICATION:
- CRANKSHAFT
$70.95 -
PROX Crank Bearing and Seal Kit 23.CBS23001
PROX
$70.95A worn crankshaft bearing or seal failure will sideline your engine and derail your season. This PROX kit delivers all the bearings and seals you need to restore your crank to OEM specifications without guesswork or compatibility issues. Whether you're...09240320- SKU:
- 09240320
- Availability:
- Ships Same Business Day
- Weight:
- 1.55 LBS
- RIDING STYLE:
- OFF-ROAD
- STYLE:
- 2-STROKE
- UNITS:
- KIT
- APPLICATION:
- CRANKSHAFT
- TYPE:
- BALL
- PRODUCT NAME:
- BEARING AND SEAL KIT
$70.95 -
PROX Crank Bearing and Seal Kit 23.CBS23083
PROX
$70.95A crankshaft bearing and seal failure can sideline your engine at the worst possible moment—leaving you stranded mid-season or mid-race. The PROX Crank Bearing and Seal Kit 23.CBS23083 delivers OEM-spec replacement bearings and seals that restore your...09240322- SKU:
- 09240322
- Availability:
- Ships Same Business Day
- Weight:
- 1.05 LBS
- RIDING STYLE:
- OFF-ROAD
- STYLE:
- 2-STROKE
- TYPE:
- BALL
- PRODUCT NAME:
- BEARING AND SEAL KIT
- UNITS:
- KIT
- APPLICATION:
- CRANKSHAFT
$70.95 -
PROX Crank Bearing and Seal Kit 23.CBS23088
PROX
$70.95A compromised crank bearing or seal can quietly undermine engine reliability and performance, turning a strong build into a liability on the track or street. The PROX Crank Bearing and Seal Kit 23.CBS23088 ensures your crankshaft assembly maintains...09240324- SKU:
- 09240324
- Availability:
- Ships Same Business Day
- Weight:
- 1.50 LBS
- PRODUCT NAME:
- BEARING AND SEAL KIT
- TYPE:
- BALL
- STYLE:
- 2-STROKE
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- APPLICATION:
- CRANKSHAFT
$70.95 -
PROX Crank Bearing and Seal Kit 23.CBS23099
PROX
$70.95A complete crankshaft bearing and seal kit is essential for any bottom-end rebuild—it ensures proper clearances, reduces friction, and extends engine life. This PROX kit eliminates guesswork by providing factory-spec components engineered to work...09240326- SKU:
- 09240326
- Availability:
- Ships Same Business Day
- Weight:
- 1.50 LBS
- PRODUCT NAME:
- BEARING AND SEAL KIT
- TYPE:
- BALL
- STYLE:
- 2-STROKE
- APPLICATION:
- CRANKSHAFT
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
$70.95 -
PROX Crank Bearing and Seal Kit 23.CBS24098
PROX
$102.95A failed crank bearing or seal doesn't just compromise performance—it can catastrophically damage your entire bottom end. This PROX kit delivers all the precision-engineered bearings and seals you need to restore your crankshaft to OEM specifications,...09240329- SKU:
- 09240329
- Availability:
- Ships Same Business Day
- Weight:
- 1.62 LBS
- APPLICATION:
- CRANKSHAFT
- TYPE:
- BALL
- RIDING STYLE:
- ATV
- RIDING STYLE:
- STREET
- STYLE:
- 4-STROKE
- PRODUCT NAME:
- BEARING SET
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
$102.95 -
PROX Crank Bearing and Seal Kit 23.CBS31089
PROX
$49.95A crankshaft rebuild demands precision-matched components to maintain tolerances and prevent premature wear. This PROX crank bearing and seal kit delivers OEM-spec parts engineered to work seamlessly with both factory and Pro X crankshafts, ensuring...09240330- SKU:
- 09240330
- 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
$49.95 -
PROX Crank Bearing and Seal Kit 23.CBS31099
PROX
$52.95A compromised crankshaft bearing or seal will leave you stranded—or worse, cost you a race. The PROX Crank Bearing and Seal Kit 23.CBS31099 delivers OEM-spec replacements that restore your crankshaft to factory performance standards, ensuring reliable...09240331- SKU:
- 09240331
- 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
$52.95 -
PROX Crank Bearing and Seal Kit 23.CBS32089
PROX
$70.95A failing crankshaft bearing or seal will compromise engine reliability and performance—and sideline you when you can't afford downtime. This complete PROX kit eliminates guesswork by including every bearing and seal your crank needs, manufactured to OEM...09240333- SKU:
- 09240333
- Availability:
- Ships Same Business Day
- Weight:
- 0.95 LBS
- APPLICATION:
- CRANKSHAFT
- PRODUCT NAME:
- BEARING AND SEAL KIT
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- STYLE:
- 2-STROKE
- TYPE:
- BALL
$70.95 -
PROX Crank Bearing and Seal Kit 23.CBS32099
PROX
$70.95A failing crankshaft bearing or seal will quickly compromise engine reliability and performance—exact OEM-specification replacements ensure you maintain factory tolerances and durability standards. This comprehensive kit eliminates the need to source...09240334- SKU:
- 09240334
- Availability:
- Ships Same Business Day
- Weight:
- 0.90 LBS
- APPLICATION:
- CRANKSHAFT
- STYLE:
- 2-STROKE
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- PRODUCT NAME:
- BEARING AND SEAL KIT
- TYPE:
- BALL
$70.95 -
PROX Crank Bearing and Seal Kit 23.CBS33003
PROX
$80.95A quality crank bearing and seal kit is essential for maintaining reliability in high-performance engines, particularly after teardowns or extended racing campaigns. This PROX kit eliminates the guesswork by supplying all necessary components...09240336- SKU:
- 09240336
- Availability:
- Ships Same Business Day
- Weight:
- 1.55 LBS
- UNITS:
- KIT
- STYLE:
- 2-STROKE
- APPLICATION:
- CRANKSHAFT
- RIDING STYLE:
- OFF-ROAD
- PRODUCT NAME:
- BEARING AND SEAL KIT
- TYPE:
- BALL
$80.95 -
PROX Crank Bearing and Seal Kit 23.CBS33007
PROX
$139.95A worn crank bearing and seal kit compromises both engine reliability and performance—exactly what you can't afford during competition or high-demand builds. The PROX 23.CBS33007 restores your crankshaft to OEM precision specifications, ensuring proper...09240337- SKU:
- 09240337
- Availability:
- Ships Same Business Day
- Weight:
- 0.92 LBS
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- APPLICATION:
- CRANKSHAFT
- TYPE:
- BALL
- STYLE:
- 4-STROKE
- PRODUCT NAME:
- BEARING AND SEAL KIT
$139.95 -
PROX Crank Bearing and Seal Kit 23.CBS33010
PROX
$159.95A complete crank bearing and seal kit is essential when rebuilding or servicing your crankshaft—neglecting worn bearings and seals is a direct path to catastrophic engine failure. The PROX 23.CBS33010 provides everything you need in one package,...09240338- SKU:
- 09240338
- Availability:
- Ships Same Business Day
- Weight:
- 1.00 LBS
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- PRODUCT NAME:
- BEARING AND SEAL KIT
- STYLE:
- 4-STROKE
- APPLICATION:
- CRANKSHAFT
- TYPE:
- BALL
$159.95 -
PROX Crank Bearing and Seal Kit 23.CBS33096
PROX
$85.95A crank bearing and seal kit is essential maintenance for any serious engine build—worn bearings compromise crankshaft stability, reduce engine longevity, and kill performance gains from your other upgrades. The PROX 23.CBS33096 delivers...09240344- SKU:
- 09240344
- Availability:
- Ships Same Business Day
- Weight:
- 1.50 LBS
- APPLICATION:
- CRANKSHAFT
- PRODUCT NAME:
- BEARING AND SEAL KIT
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- STYLE:
- 2-STROKE
- TYPE:
- BALL
$85.95 -
PROX Crank Bearing and Seal Kit 23.CBS34005
PROX
$109.95A complete crank bearing and seal kit is essential for any serious engine rebuild—whether you're restoring a factory powerplant or upgrading to a Pro X crankshaft. This OEM-specification kit ensures proper clearances, oil circulation, and longevity under...09240346- SKU:
- 09240346
- Availability:
- Ships Same Business Day
- Weight:
- 1.65 LBS
- APPLICATION:
- CRANKSHAFT
- TYPE:
- BALL
- STYLE:
- 4-STROKE
- PRODUCT NAME:
- BEARING SET
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
$109.95
