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 Piston Kit 01.2217.B
PROX
$105.95Manufactured in Japan and designed to be OEM replacement, Cast from a high-silicon-content aluminum alloy that meets or exceeds OEM specifications, then CNC-machined to extremely close tolerances, Pistons supplied in a kit package that includes rings,...PX7215B- SKU:
- PX7215B
- Availability:
- Ships Same Business Day
- Weight:
- 0.44 LBS
- PISTON DIAMETER METRIC:
- 53.96 MM
- RIDING STYLE:
- OFF-ROAD
- BORE SIZE METRIC:
- 53.96 MM
- ENGINE TYPE:
- 2-STROKE
- PISTON SIZE METRIC:
- +0.01 MM
- PRODUCT NAME:
- PISTON KIT
- PISTON MATERIAL:
- ALUMINUM ALLOY
- UNITS:
- EACH
$105.95 -
PROX Piston Kit 01.2217.C
PROX
$105.95Manufactured in Japan and designed to be OEM replacement, Cast from a high-silicon-content aluminum alloy that meets or exceeds OEM specifications, then CNC-machined to extremely close tolerances, Pistons supplied in a kit package that includes rings,...PX7215C- SKU:
- PX7215C
- Availability:
- Ships Same Business Day
- Weight:
- 0.44 LBS
- ENGINE TYPE:
- 2-STROKE
- PISTON SIZE METRIC:
- +0.02 MM
- PRODUCT NAME:
- PISTON KIT
- PISTON DIAMETER METRIC:
- 53.97 MM
- RIDING STYLE:
- OFF-ROAD
- BORE SIZE METRIC:
- 53.97 MM
- PISTON MATERIAL:
- ALUMINUM ALLOY
- UNITS:
- EACH
$105.95 -
PROX PRO-X Crank Seal Kit 42.2102
PROX
$9.95OEM quality, All seals necessary for complete crank rebuild included094280- SKU:
- 094280
- Availability:
- Ships Same Business Day
- Weight:
- 0.08 LBS
$9.95 -
PROX PRO-X Crank Seal Kit 42.2319
PROX
$19.95OEM quality, All seals necessary for complete crank rebuild included094288- SKU:
- 094288
- Availability:
- Ships Same Business Day
- Weight:
- 0.08 LBS
$19.95 -
PROX PRO-X Crank Seal Kit 42.2321
PROX
$19.95OEM quality, All seals necessary for complete crank rebuild included094289- SKU:
- 094289
- Availability:
- Ships Same Business Day
- Weight:
- 0.10 LBS
$19.95 -
PROX PRO-X Crank Seal Kit 42.2221
PROX
$19.95OEM quality, All seals necessary for complete crank rebuild included094290- SKU:
- 094290
- Availability:
- Ships Same Business Day
- Weight:
- 0.08 LBS
$19.95 -
PROX PRO-X Crank Seal Kit 42.3316
PROX
$29.95OEM quality, All seals necessary for complete crank rebuild included094395- SKU:
- 094395
- Availability:
- Ships Same Business Day
- Weight:
- 0.06 LBS
$29.95 -
PROX PRO-X Crank Seal Kit 42.3219
PROX
$24.95OEM quality, All seals necessary for complete crank rebuild included094398- SKU:
- 094398
- Availability:
- Ships Same Business Day
- Weight:
- 0.08 LBS
$24.95 -
PROX PRO-X Crank Seal Kit 42.4105
PROX
$9.95OEM quality, All seals necessary for complete crank rebuild included094481- SKU:
- 094481
- Availability:
- Ships Same Business Day
- Weight:
- 0.08 LBS
$9.95 -
PROX PRO-X Crank Seal Kit 42.4208
PROX
$19.95OEM quality, All seals necessary for complete crank rebuild included094484- SKU:
- 094484
- Availability:
- Ships Same Business Day
- Weight:
- 0.08 LBS
$19.95 -
PROX PRO-X Crank Seal Kit 42.4288
PROX
$9.95OEM quality, All seals necessary for complete crank rebuild included094487- SKU:
- 094487
- Availability:
- Ships Same Business Day
- Weight:
- 0.20 LBS
$9.95 -
PROX PRO-X Crank Seal Kit 42.4300
PROX
$29.95OEM quality, All seals necessary for complete crank rebuild included094488- SKU:
- 094488
- Availability:
- Ships Same Business Day
- Weight:
- 0.08 LBS
$29.95 -
PROX PRO-X Crank Seal Kit 42.4403
PROX
$9.95OEM quality, All seals necessary for complete crank rebuild included094489- SKU:
- 094489
- Availability:
- Ships Same Business Day
- Weight:
- 0.08 LBS
$9.95 -
PROX PRO-X Crank Seal Kit 42.1103
PROX
$9.95OEM quality, All seals necessary for complete crank rebuild included094181- SKU:
- 094181
- Availability:
- Ships Same Business Day
- Weight:
- 0.08 LBS
$9.95 -
PROX PRO-X Crank Seal Kit 42.1206
PROX
$9.95OEM quality, All seals necessary for complete crank rebuild included094184- SKU:
- 094184
- Availability:
- Ships Same Business Day
- Weight:
- 0.06 LBS
$9.95 -
PROX PRO-X Crank Seal Kit 42.1312
PROX
$14.95OEM quality, All seals necessary for complete crank rebuild included094187- SKU:
- 094187
- Availability:
- Ships Same Business Day
- Weight:
- 0.08 LBS
$14.95 -
PROX Crank Seal Kit - CR250/500 42.1304
PROX
$9.95OEM quality, All seals necessary for complete crank rebuild included09350292- SKU:
- 09350292
- Availability:
- Ships Same Business Day
- Weight:
- 0.10 LBS
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- APPLICATION:
- CRANKSHAFT
- TYPE:
- OIL
- PRODUCT NAME:
- SEAL
$9.95 -
PROX Crank Seal Kit - CRF250R 42.1405
PROX
$19.95OEM quality, All seals necessary for complete crank rebuild included09350294- SKU:
- 09350294
- Availability:
- Ships Same Business Day
- Weight:
- 0.10 LBS
- APPLICATION:
- CRANKSHAFT
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- PRODUCT NAME:
- SEAL
- TYPE:
- OIL
$19.95 -
PROX Crank Seal Kit - RM250 42.3325
PROX
$29.95OEM quality, All seals necessary for complete crank rebuild included09350315- SKU:
- 09350315
- Availability:
- Ships Same Business Day
- Weight:
- 0.10 LBS
- APPLICATION:
- CRANKSHAFT
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- TYPE:
- OIL
- PRODUCT NAME:
- SEAL
$29.95Qty in Cart: 0Quantity:Price:$29.95Subtotal: -
PROX Crank Seal Kit - KTM60/65SX 42.6017
PROX
$14.95OEM quality, All seals necessary for complete crank rebuild included09350319- SKU:
- 09350319
- Availability:
- Ships Same Business Day
- Weight:
- 0.10 LBS
- PRODUCT NAME:
- SEAL
- UNITS:
- KIT
- APPLICATION:
- CRANKSHAFT
- TYPE:
- OIL
- RIDING STYLE:
- OFF-ROAD
$14.95
