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
-
On Sale
PROX Piston Kit - Standard - KTM 125SX 01.6220.B
PROX
MSRP: $124.95Now: $106.00Was: $124.95Piston Kit for offroad applications09106107- SKU:
- 09106107
- Availability:
- Ships Same Business Day
- Weight:
- 0.40 LBS
- BORE - OVERSIZE:
- STANDARD
- BORE - OVERSIZE METRIC:
- STANDARD
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- BORE SIZE METRIC:
- 53.95 MM
- PRODUCT NAME:
- PISTON KIT
MSRP: $124.95Now: $106.00Was: $124.95Qty in Cart: 0Quantity:Price:MSRP: $124.95Now: $106.00Was: $124.95Subtotal: -
On Sale
PROX Piston Kit - Standard - 200EXC 01.6249.B
PROX
MSRP: $139.95Now: $119.00Was: $139.95Piston Kit for offroad applications09106109- SKU:
- 09106109
- Availability:
- Ships Same Business Day
- Weight:
- 0.60 LBS
- BORE SIZE METRIC:
- 63.95 MM
- PRODUCT NAME:
- PISTON KIT
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- BORE - OVERSIZE:
- STANDARD
- BORE - OVERSIZE METRIC:
- STANDARD
MSRP: $139.95Now: $119.00Was: $139.95 -
On Sale
PROX Piston Rings 02.4336
PROX
MSRP: $49.95Now: $42.00Was: $49.95High quality rings which allow for optimum heat transfer and sealing09120655- SKU:
- 09120655
- Availability:
- Ships Same Business Day
- Weight:
- 0.04 LBS
- PISTON MATERIAL:
- ALUMINUM ALLOY
- BORE SIZE METRIC:
- 76.96 MM - 76.98 MM
- PRODUCT NAME:
- PISTON RING
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- PAIR
MSRP: $49.95Now: $42.00Was: $49.95Qty in Cart: 0Quantity:Price:MSRP: $49.95Now: $42.00Was: $49.95Subtotal: -
On Sale
PROX Piston Rings 02.6351
PROX
MSRP: $49.95Now: $42.00Was: $49.95High quality rings which allow for optimum heat transfer and sealing09120661- SKU:
- 09120661
- Availability:
- Ships Same Business Day
- Weight:
- 0.05 LBS
- UNITS:
- PAIR
- BORE SIZE METRIC:
- 87.96 MM - 87.98 MM
- RIDING STYLE:
- OFF-ROAD
- PISTON MATERIAL:
- ALUMINUM ALLOY
- PRODUCT NAME:
- PISTON RING
MSRP: $49.95Now: $42.00Was: $49.95Qty in Cart: 0Quantity:Price:MSRP: $49.95Now: $42.00Was: $49.95Subtotal: -
On Sale
PROX Crank Bearing and Seal Kit 23.CBS12007
PROX
MSRP: $105.95Now: $90.00Was: $105.95Made to exact OEM specifications for maximum performance and durability, Includes all necessary bearings/seals for a component's replacement, For use with OEM or Pro X crankshafts09240295- SKU:
- 09240295
- Availability:
- Ships Same Business Day
- Weight:
- 0.90 LBS
- RIDING STYLE:
- OFF-ROAD
- STYLE:
- 4-STROKE
- PRODUCT NAME:
- BEARING AND SEAL KIT
- UNITS:
- KIT
- TYPE:
- BALL
- APPLICATION:
- CRANKSHAFT
MSRP: $105.95Now: $90.00Was: $105.95Qty in Cart: 0Quantity:Price:MSRP: $105.95Now: $90.00Was: $105.95Subtotal: -
On Sale
PROX Crank Bearing and Seal Kit 23.CBS12080
PROX
MSRP: $55.95Now: $48.00Was: $55.95Made to exact OEM specifications for maximum performance and durability, Includes all necessary bearings/seals for a component's replacement, For use with OEM or Pro X crankshafts09240296- SKU:
- 09240296
- Availability:
- Ships Same Business Day
- Weight:
- 1.00 LBS
- APPLICATION:
- CRANKSHAFT
- PRODUCT NAME:
- BEARING AND SEAL KIT
- UNITS:
- KIT
- TYPE:
- BALL
- RIDING STYLE:
- OFF-ROAD
- STYLE:
- 2-STROKE
MSRP: $55.95Now: $48.00Was: $55.95Qty in Cart: 0Quantity:Price:MSRP: $55.95Now: $48.00Was: $55.95Subtotal: -
On Sale
PROX Crank Bearing and Seal Kit 23.CBS13006
PROX
MSRP: $109.95Now: $93.00Was: $109.95Made to exact OEM specifications for maximum performance and durability, Includes all necessary bearings/seals for a component's replacement, For use with OEM or Pro X crankshafts09240299- SKU:
- 09240299
- Availability:
- Ships Same Business Day
- Weight:
- 1.05 LBS
- PRODUCT NAME:
- BEARING AND SEAL KIT
- APPLICATION:
- CRANKSHAFT
- TYPE:
- BALL
- STYLE:
- 4-STROKE
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
MSRP: $109.95Now: $93.00Was: $109.95 -
On Sale
PROX Crank Bearing and Seal Kit 23.CBS13087
PROX
MSRP: $65.95Now: $56.00Was: $65.95Made to exact OEM specifications for maximum performance and durability, Includes all necessary bearings/seals for a component's replacement, For use with OEM or Pro X crankshafts09240301- SKU:
- 09240301
- Availability:
- Ships Same Business Day
- Weight:
- 1.65 LBS
- APPLICATION:
- CRANKSHAFT
- TYPE:
- BALL
- PRODUCT NAME:
- BEARING AND SEAL KIT
- RIDING STYLE:
- ATV
- STYLE:
- 2-STROKE
- UNITS:
- KIT
MSRP: $65.95Now: $56.00Was: $65.95Qty in Cart: 0Quantity:Price:MSRP: $65.95Now: $56.00Was: $65.95Subtotal: -
On Sale
PROX Crank Bearing and Seal Kit 23.CBS23080
PROX
MSRP: $65.95Now: $56.00Was: $65.95Made to exact OEM specifications for maximum performance and durability, Includes all necessary bearings/seals for a component's replacement, For use with OEM or Pro X crankshafts09240321- SKU:
- 09240321
- Availability:
- Ships Same Business Day
- Weight:
- 1.80 LBS
- RIDING STYLE:
- OFF-ROAD
- STYLE:
- 2-STROKE
- UNITS:
- KIT
- PRODUCT NAME:
- BEARING AND SEAL KIT
- APPLICATION:
- CRANKSHAFT
- TYPE:
- BALL
MSRP: $65.95Now: $56.00Was: $65.95Qty in Cart: 0Quantity:Price:MSRP: $65.95Now: $56.00Was: $65.95Subtotal: -
On Sale
PROX Crank Bearing and Seal Kit 23.CBS33094
PROX
MSRP: $75.95Now: $65.00Was: $75.95Made to exact OEM specifications for maximum performance and durability, Includes all necessary bearings/seals for a component's replacement, For use with OEM or Pro X crankshafts09240343- SKU:
- 09240343
- 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
MSRP: $75.95Now: $65.00Was: $75.95Qty in Cart: 0Quantity:Price:MSRP: $75.95Now: $65.00Was: $75.95Subtotal: -
On Sale
PROX Connecting Rod Kit - Honda CRF450R 03.1417
PROX
MSRP: $175.95Now: $150.00Was: $175.95Come complete with crankpin, big-end bearing, small-end bearing and washers, Easy to install09230460- SKU:
- 09230460
- Availability:
- Ships Same Business Day
- Weight:
- 1.50 LBS
- PRODUCT NAME:
- CONNECTING ROD KIT
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
MSRP: $175.95Now: $150.00Was: $175.95 -
On Sale
PROX Connecting Rod Kit 03.2440
PROX
MSRP: $175.95Now: $150.00Was: $175.95Comes complete with crankpin, big-end bearing, small-end bearing, and washers, Easy to install09230279- SKU:
- 09230279
- Availability:
- Ships Same Business Day
- Weight:
- 1.55 LBS
- ENGINE TYPE:
- 4-STROKE
- PRODUCT NAME:
- CONNECTING ROD KIT
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- EACH
- MATERIAL:
- FORGED STEEL
MSRP: $175.95Now: $150.00Was: $175.95Qty in Cart: 0Quantity:Price:MSRP: $175.95Now: $150.00Was: $175.95Subtotal: -
On Sale
PROX Connecting Rod Kit - Honda CRF150R 03.1227
PROX
MSRP: $124.95Now: $106.00Was: $124.95Come complete with crankpin, big-end bearing, small-end bearing and washers, Easy to install09230237- SKU:
- 09230237
- Availability:
- Ships Same Business Day
- Weight:
- 0.74 LBS
- ENGINE TYPE:
- 2-STROKE
- MATERIAL:
- FORGED
- MATERIAL:
- STEEL
- PRODUCT NAME:
- CONNECTING ROD KIT
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
MSRP: $124.95Now: $106.00Was: $124.95 -
On Sale
PROX Connecting Rod Kit 03.1660
PROX
MSRP: $199.95Now: $170.00Was: $199.95Comes complete with crankpin, big-end bearing, small-end bearing, and washers, Easy to install09230241- SKU:
- 09230241
- Availability:
- Ships Same Business Day
- Weight:
- 2.27 LBS
- ENGINE TYPE:
- 4-STROKE
- MATERIAL:
- FORGED STEEL
- PRODUCT NAME:
- CONNECTING ROD KIT
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- EACH
MSRP: $199.95Now: $170.00Was: $199.95 -
On Sale
PROX Connecting Rod Kit 03.4409
PROX
MSRP: $175.95Now: $150.00Was: $175.95Comes complete with crankpin, big-end bearing, small-end bearing, and washers, Easy to install09230245- SKU:
- 09230245
- Availability:
- Ships Same Business Day
- Weight:
- 1.63 LBS
- ENGINE TYPE:
- 4-STROKE
- MATERIAL:
- FORGED STEEL
- PRODUCT NAME:
- CONNECTING ROD KIT
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- EACH
MSRP: $175.95Now: $150.00Was: $175.95 -
On Sale
PROX Connecting Rod Kit 03.6528
PROX
MSRP: $179.95Now: $153.00Was: $179.95Comes complete with crankpin, big-end bearing, small-end bearing, and washers, Easy to install09230248- SKU:
- 09230248
- Availability:
- Ships Same Business Day
- Weight:
- 1.79 LBS
- UNITS:
- EACH
- ENGINE TYPE:
- 4-STROKE
- PRODUCT NAME:
- CONNECTING ROD KIT
- RIDING STYLE:
- OFF-ROAD
- MATERIAL:
- FORGED STEEL
MSRP: $179.95Now: $153.00Was: $179.95 -
On Sale
PROX Connecting Rod 03.1212
PROX
MSRP: $119.95Now: $102.00Was: $119.95Comes complete with crankpin, big-end bearing, small-end bearing, and washers, Easy to install09230126- SKU:
- 09230126
- Availability:
- Ships Same Business Day
- Weight:
- 0.72 LBS
- ENGINE TYPE:
- 2-STROKE
- FEATURES:
- INCLUDES THRUST WASHERS
- MATERIAL:
- FORGED STEEL
- PRODUCT NAME:
- CONNECTING ROD KIT
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- EACH
MSRP: $119.95Now: $102.00Was: $119.95 -
On Sale
PROX Connecting Rod 03.1402
PROX
MSRP: $175.95Now: $150.00Was: $175.95Comes complete with crankpin, big-end bearing, small-end bearing, and washers, Easy to install09230129- SKU:
- 09230129
- Availability:
- Ships Same Business Day
- Weight:
- 1.59 LBS
- ENGINE TYPE:
- 4-STROKE
- PRODUCT NAME:
- CONNECTING ROD KIT
- RIDING STYLE:
- OFF-ROAD
- FEATURES:
- INCLUDES THRUST WASHERS
- MATERIAL:
- FORGED STEEL
- UNITS:
- EACH
MSRP: $175.95Now: $150.00Was: $175.95Qty in Cart: 0Quantity:Price:MSRP: $175.95Now: $150.00Was: $175.95Subtotal: -
On Sale
PROX Connecting Rod 03.6023
PROX
MSRP: $109.95Now: $93.00Was: $109.95Comes complete with crankpin, big-end bearing, small-end bearing, and washers, Easy to install09230151- SKU:
- 09230151
- Availability:
- Ships Same Business Day
- Weight:
- 0.51 LBS
- UNITS:
- EACH
- PRODUCT NAME:
- CONNECTING ROD KIT
- RIDING STYLE:
- OFF-ROAD
- ENGINE TYPE:
- 2-STROKE
- MATERIAL:
- FORGED STEEL
MSRP: $109.95Now: $93.00Was: $109.95Qty in Cart: 0Quantity:Price:MSRP: $109.95Now: $93.00Was: $109.95Subtotal: -
On Sale
PROX Connecting Rod 03.2426
PROX
MSRP: $175.95Now: $150.00Was: $175.95Comes complete with crankpin, big-end bearing, small-end bearing, and washers, Easy to install09230183- SKU:
- 09230183
- Availability:
- Ships Same Business Day
- Weight:
- 1.51 LBS
- MATERIAL:
- FORGED STEEL
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- EACH
- ENGINE TYPE:
- 4-STROKE
- PRODUCT NAME:
- CONNECTING ROD KIT
MSRP: $175.95Now: $150.00Was: $175.95
