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.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...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...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...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...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...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...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.CBS32087
PROX
$45.95A worn or damaged crank bearing and seal kit will rob your engine of reliability and efficiency—compromising both performance and longevity. The PROX 23.CBS32087 delivers OEM-spec precision...09240332- SKU:
- 09240332
- Availability:
- Ships Same Business Day
- Weight:
- 0.80 LBS
- APPLICATION:
- CRANKSHAFT
- TYPE:
- BALL
- PRODUCT NAME:
- BEARING AND SEAL KIT
- UNITS:
- KIT
- RIDING STYLE:
- OFF-ROAD
- STYLE:
- 2-STROKE
$45.95Qty in Cart: 0Quantity:Price:$45.95Subtotal: -
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...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...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.CBS33000
PROX
$80.95A failed crankshaft bearing or seal can sideline your engine at the worst possible moment—mid-race or mid-season. The PROX Crank Bearing and Seal Kit 23.CBS33000 gives you a complete,...09240335- SKU:
- 09240335
- Availability:
- Ships Same Business Day
- Weight:
- 1.50 LBS
- APPLICATION:
- CRANKSHAFT
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- STYLE:
- 2-STROKE
- PRODUCT NAME:
- BEARING AND SEAL KIT
- TYPE:
- BALL
$80.95 -
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...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...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...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...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
$85.95Qty in Cart: 0Quantity:Price:$85.95Subtotal: -
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...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
$109.95Qty in Cart: 0Quantity:Price:$109.95Subtotal: -
PROX Crank Bearing and Seal Kit 23.CBS34008
PROX
$156.95A crankshaft rebuild demands precision—and a single worn bearing or seal will compromise your entire bottom end. The PROX Crank Bearing and Seal Kit 23.CBS34008 delivers OEM-exact replacements for...09240347- SKU:
- 09240347
- Availability:
- Ships Same Business Day
- Weight:
- 1.73 LBS
- PRODUCT NAME:
- BEARING AND SEAL KIT
- STYLE:
- 4-STROKE
- APPLICATION:
- CRANKSHAFT
- TYPE:
- BALL
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
$156.95 -
PROX Crank Bearing and Seal Kit 23.CBS42085
PROX
$65.95A quality crank bearing and seal kit is essential for reliable engine performance and longevity. Worn or failing bearings increase friction, reduce power transfer, and risk catastrophic engine damage...09240351- SKU:
- 09240351
- Availability:
- Ships Same Business Day
- Weight:
- 1.05 LBS
- RIDING STYLE:
- OFF-ROAD
- STYLE:
- 2-STROKE
- UNITS:
- KIT
- PRODUCT NAME:
- BEARING AND SEAL KIT
- APPLICATION:
- CRANKSHAFT
- TYPE:
- BALL
$65.95Qty in Cart: 0Quantity:Price:$65.95Subtotal: -
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.CBS43003
PROX
$135.95A crankshaft rebuild demands precision—bearing failure or seal degradation can cascade into catastrophic engine damage. This Pro X crank bearing and seal kit eliminates guesswork by supplying every...09240355- SKU:
- 09240355
- Availability:
- Ships Same Business Day
- Weight:
- 1.69 LBS
- APPLICATION:
- CRANKSHAFT
- STYLE:
- 2-STROKE
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- PRODUCT NAME:
- BEARING AND SEAL KIT
- TYPE:
- BALL
$135.95Qty in Cart: 0Quantity:Price:$135.95Subtotal:
