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
-
HOT RODS Crankshaft Kit CBK0128
HOT RODS
$741.95Whether you're building a stroker engine or replacing a worn OEM crankshaft, the HOT RODS CBK0128 Crankshaft Kit delivers factory-matched precision with measurable performance gains. This complete assembly arrives factory-assembled and true to OEM...09210362- SKU:
- 09210362
- Availability:
- Ships Same Business Day
- Weight:
- 10.64 LBS
- PRODUCT NAME:
- CRANKSHAFT KIT
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- TYPE:
- OEM
$741.95 -
HOT RODS Crankshaft Kit CBK0129
HOT RODS
$835.95If you're building a high-performance engine that demands reliability under extreme conditions, the HOT RODS Crankshaft Kit CBK0129 delivers the precision and durability you need. This factory-assembled crankshaft meets or exceeds OEM specifications...09210363- SKU:
- 09210363
- Availability:
- Ships Same Business Day
- Weight:
- 13.10 LBS
- UNITS:
- KIT
- RIDING STYLE:
- OFF-ROAD
- PRODUCT NAME:
- CRANKSHAFT KIT
- TYPE:
- OEM
$835.95 -
HOT RODS Crankshaft Kit CBK0133
HOT RODS
$442.95A quality crankshaft is the foundation of engine reliability and performance—especially if you're pushing your build beyond stock parameters. The HOT RODS Crankshaft Kit CBK0133 arrives factory-assembled and pre-checked to meet or exceed OEM...09210365- SKU:
- 09210365
- Availability:
- Ships Same Business Day
- Weight:
- 6.60 LBS
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- PRODUCT NAME:
- CRANKSHAFT KIT
- TYPE:
- STROKER
$442.95 -
HOT RODS Crankshaft Kit CBK0134
HOT RODS
$370.95If you're building a high-displacement engine or need a crankshaft that matches OEM specifications without compromise, the HOT RODS Crankshaft Kit CBK0134 delivers factory-level precision with proven durability. This complete assembly arrives ready for...09210366- SKU:
- 09210366
- Availability:
- Ships Same Business Day
- Weight:
- 6.07 LBS
- PRODUCT NAME:
- CRANKSHAFT KIT
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- TYPE:
- STROKER
$370.95 -
HOT RODS Crankshaft 4024
HOT RODS
$476.95A high-performance crankshaft built to withstand the demands of serious ATV racing and trail riding. The HOT RODS 4024 arrives factory-assembled and pre-trued to OEM specifications, eliminating guesswork and machine work—you get a complete,...09210234- SKU:
- 09210234
- Availability:
- Ships Same Business Day
- Weight:
- 6.80 LBS
- RIDING STYLE:
- OFF-ROAD
- DISPLACEMENT:
- 125 CC
- MATERIAL:
- 4140 STEEL
- UNITS:
- ASSEMBLY
- COLOR/FINISH:
- STEEL
- PRODUCT NAME:
- CRANKSHAFT ASSEMBLY
- FEATURES:
- STANDARD CRANKSHAFT
- MODEL:
- 2-CYCLE
- STROKE LENGTH METRIC:
- 54.50 MM
- TYPE:
- OEM STROKE
$476.95 -
HOT RODS Crankshaft 4025
HOT RODS
$595.95If you're building a long-stroke engine for your ATV or sport quad, you need a crankshaft engineered to handle the demands of extended stroke geometry without sacrificing reliability. The HOT RODS Crankshaft 4025 arrives factory-assembled, trued to OEM...09210235- SKU:
- 09210235
- Availability:
- Ships Same Business Day
- Weight:
- 6.85 LBS
- DISPLACEMENT:
- 144 CC TO 150 CC
- PRODUCT NAME:
- CRANKSHAFT ASSEMBLY
- STROKE LENGTH METRIC:
- 58.30 MM
- COLOR/FINISH:
- STEEL
- FEATURES:
- STANDARD CRANKSHAFT
- RIDING STYLE:
- OFF-ROAD
- MATERIAL:
- 4140 STEEL
- UNITS:
- ASSEMBLY
- MODEL:
- 2-CYCLE
- TYPE:
- OEM STROKE
$595.95 -
HOT RODS Crankshaft 4029
HOT RODS
$662.95If you're serious about maximizing your ATV's displacement and power output, a long-stroke crankshaft is one of the most effective modifications available—and Hot Rods 4029 eliminates the guesswork with a factory-assembled, trued unit that's ready to...09210238- SKU:
- 09210238
- Availability:
- Ships Same Business Day
- Weight:
- 7.24 LBS
- COLOR/FINISH:
- STEEL
- MATERIAL:
- 4140 STEEL
- RIDING STYLE:
- OFF-ROAD
- STROKE LENGTH METRIC:
- 54.80 MM
- UNITS:
- ASSEMBLY
- FEATURES:
- STANDARD CRANKSHAFT
- TYPE:
- OEM STROKE
- DISPLACEMENT:
- 250 CC
- MODEL:
- 4-CYCLE
- PRODUCT NAME:
- CRANKSHAFT ASSEMBLY
$662.95 -
HOT RODS Crankshaft 4030
HOT RODS
$476.95If you're building a long-stroke engine for your ATV or sport quad, the HOT RODS Crankshaft 4030 eliminates the guesswork and machine work typically required for this conversion. This complete assembly arrives factory-assembled and trued to OEM...09210239- SKU:
- 09210239
- Availability:
- Ships Same Business Day
- Weight:
- 13.33 LBS
- COLOR/FINISH:
- STEEL
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- ASSEMBLY
- DISPLACEMENT:
- 500 CC
- MODEL:
- 2-CYCLE
- PRODUCT NAME:
- CRANKSHAFT ASSEMBLY
- STROKE LENGTH METRIC:
- 79.00 MM
- MATERIAL:
- 4140 STEEL
- TYPE:
- OEM STROKE
- FEATURES:
- STANDARD CRANKSHAFT
$476.95Qty in Cart: 0Quantity:Price:$476.95Subtotal: -
HOT RODS Crankshaft 4046
HOT RODS
$515.95If you're running a long-stroke build on your ATV, a properly engineered crankshaft is non-negotiable—it's the foundation of reliability under sustained high RPM loads. The HOT RODS 4046 arrives factory-assembled and trued to OEM specifications,...09210240- SKU:
- 09210240
- Availability:
- Ships Same Business Day
- Weight:
- 6.95 LBS
- DISPLACEMENT:
- 200 CC
- FEATURES:
- STANDARD CRANKSHAFT
- MODEL:
- 2-CYCLE
- TYPE:
- OEM STROKE
- MATERIAL:
- 4140 STEEL
- UNITS:
- ASSEMBLY
- PRODUCT NAME:
- CRANKSHAFT ASSEMBLY
- COLOR/FINISH:
- STEEL
- RIDING STYLE:
- OFF-ROAD
- STROKE LENGTH METRIC:
- 59.90 MM
$515.95Qty in Cart: 0Quantity:Price:$515.95Subtotal: -
HOT RODS Crankshaft 4096
HOT RODS
$489.95If you're building a long-stroke engine for your high-performance ATV, the HOT RODS Crankshaft 4096 eliminates the guesswork and machine work typically required for displacement increases. This complete assembly arrives factory-assembled and trued to OEM...09210242- SKU:
- 09210242
- Availability:
- Ships Same Business Day
- Weight:
- 7.10 LBS
- MODEL:
- 4-CYCLE
- TYPE:
- OEM STROKE
- FEATURES:
- HEAVY DUTY CRANKSHAFT
- MATERIAL:
- 4140 STEEL
- UNITS:
- ASSEMBLY
- DISPLACEMENT:
- 250 CC
- PRODUCT NAME:
- CRANKSHAFT ASSEMBLY
- STROKE LENGTH METRIC:
- 53.60 MM
- COLOR/FINISH:
- STEEL
- RIDING STYLE:
- OFF-ROAD
$489.95 -
HOT RODS Crankshaft 4097
HOT RODS
$476.95If you're building a long-stroke engine for your ATV, the HOT RODS Crankshaft 4097 eliminates the guesswork and machine work typically required for high-displacement builds. Factory-assembled and trued to OEM specifications, this complete crankshaft...09210243- SKU:
- 09210243
- Availability:
- Ships Same Business Day
- Weight:
- 7.45 LBS
- FEATURES:
- STANDARD CRANKSHAFT
- MODEL:
- 4-CYCLE
- TYPE:
- OEM STROKE
- DISPLACEMENT:
- 250 CC
- PRODUCT NAME:
- CRANKSHAFT ASSEMBLY
- STROKE LENGTH METRIC:
- 53.80 MM
- MATERIAL:
- 4140 STEEL
- UNITS:
- ASSEMBLY
- COLOR/FINISH:
- STEEL
- RIDING STYLE:
- OFF-ROAD
$476.95 -
HOT RODS Crankshaft Assembly 4058
HOT RODS
$609.95If you're building a high-performance ATV engine or planning a long-stroke upgrade, the HOT RODS Crankshaft Assembly 4058 delivers factory-proven reliability without compromise. This complete assembly arrives factory-assembled and trued to OEM specs,...09210026- SKU:
- 09210026
- Availability:
- Ships Same Business Day
- Weight:
- 9.04 LBS
- COLOR/FINISH:
- STEEL
- PRODUCT NAME:
- CRANKSHAFT ASSEMBLY
- RIDING STYLE:
- OFF-ROAD
- MATERIAL:
- 4140 STEEL
- UNITS:
- ASSEMBLY
- DISPLACEMENT:
- 250 CC
- FEATURES:
- STANDARD CRANKSHAFT
- MODEL:
- 2-CYCLE
- STROKE LENGTH METRIC:
- 72.00 MM
- TYPE:
- OEM STROKE
$609.95 -
HOT RODS Crankshaft Assembly 4054
HOT RODS
$423.95If you're building a high-revving ATV engine or pushing your machine beyond stock limits, a quality crankshaft assembly is non-negotiable—it's the foundation of reliability under extreme conditions. The HOT RODS Crankshaft Assembly 4054 arrives...09210027- SKU:
- 09210027
- Availability:
- Ships Same Business Day
- Weight:
- 6.22 LBS
- COLOR/FINISH:
- STEEL
- RIDING STYLE:
- OFF-ROAD
- STROKE LENGTH METRIC:
- 54.60 MM
- DISPLACEMENT:
- 125 CC
- MATERIAL:
- 4140 STEEL
- UNITS:
- ASSEMBLY
- PRODUCT NAME:
- CRANKSHAFT ASSEMBLY
- FEATURES:
- STANDARD CRANKSHAFT
- MODEL:
- 2-CYCLE
- TYPE:
- OEM STROKE
$423.95 -
HOT RODS Crankshaft Assembly 4041
HOT RODS
$476.95If you're building a long-stroke engine for your ATV, the HOT RODS Crankshaft Assembly 4041 eliminates guesswork and machine work by delivering a factory-assembled, trued crankshaft ready for bolt-in installation. This complete assembly pairs proven...09210016- SKU:
- 09210016
- Availability:
- Ships Same Business Day
- Weight:
- 6.55 LBS
- DISPLACEMENT:
- 125 CC
- PRODUCT NAME:
- CRANKSHAFT ASSEMBLY
- FEATURES:
- STANDARD CRANKSHAFT
- STROKE LENGTH METRIC:
- 54.60 MM
- TYPE:
- OEM STROKE
- MODEL:
- 2-CYCLE
- COLOR/FINISH:
- STEEL
- MATERIAL:
- 4140 STEEL
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- ASSEMBLY
$476.95Qty in Cart: 0Quantity:Price:$476.95Subtotal: -
HOT RODS Crankshaft Assembly 4050
HOT RODS
$515.95If you're building a long-stroke engine for your ATV, you need a crankshaft assembly engineered to handle the demands of increased displacement and extended power delivery. The HOT RODS Crankshaft Assembly 4050 arrives factory-assembled, trued to OEM...09210017- SKU:
- 09210017
- Availability:
- Ships Same Business Day
- Weight:
- 8.63 LBS
- MODEL:
- 4-CYCLE
- PRODUCT NAME:
- CRANKSHAFT ASSEMBLY
- DISPLACEMENT:
- 450 CC
- FEATURES:
- HEAVY DUTY CRANKSHAFT
- MATERIAL:
- 4140 STEEL
- STROKE LENGTH METRIC:
- 63.40 MM
- TYPE:
- OEM STROKE
- COLOR/FINISH:
- STEEL
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- ASSEMBLY
$515.95 -
HOT RODS Crankshaft 4081
HOT RODS
$595.95If you're building a long-stroke engine for your ATV, the HOT RODS Crankshaft 4081 eliminates the guesswork and machine work typically required for displacement increases. This complete assembly arrives factory-assembled and trued to OEM specifications,...09210136- SKU:
- 09210136
- Availability:
- Ships Same Business Day
- Weight:
- 7.26 LBS
- PRODUCT NAME:
- CRANKSHAFT ASSEMBLY
- COLOR/FINISH:
- STEEL
- FEATURES:
- STANDARD CRANKSHAFT
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- OEM STROKE
- MODEL:
- 4-CYCLE
- DISPLACEMENT:
- 250 CC
- MATERIAL:
- 4140 STEEL
- STROKE LENGTH METRIC:
- 53.60 MM
- UNITS:
- ASSEMBLY
$595.95 -
COMETIC Top End Gasket Kit - DT200 C7142
COMETIC
$32.95A failed top end gasket can cost you races, reliability, and credibility. The COMETIC C7142 kit delivers the sealing integrity and heat management you need to run hard—whether you're naturally aspirated or forced induction. Multi-layered steel...09340369- SKU:
- 09340369
- Availability:
- Ships Same Business Day
- Weight:
- 0.09 LBS
- PRODUCT NAME:
- GASKET KIT
- BORE SIZE METRIC:
- 68.00 MM
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- TYPE:
- TOP END
$32.95 -
COMETIC Top End Gasket Kit - CR85 C7315
COMETIC
$34.95A quality top-end gasket kit is non-negotiable if you're rebuilding your CR85 engine or chasing reliability at the track. COMETIC's C7315 kit delivers the precision sealing you need to maintain compression, prevent coolant weeping, and keep cylinder...09340380- SKU:
- 09340380
- Availability:
- Ships Same Business Day
- Weight:
- 0.06 LBS
- PRODUCT NAME:
- GASKET KIT
- THICKNESS METRIC:
- 0.31 MM
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- THICKNESS IMPERIAL:
- 0,012'
- TYPE:
- TOP END
- BORE SIZE METRIC:
- 52.00 MM
$34.95 -
COMETIC Top End Gasket Kit - YZ426F C7689
COMETIC
$47.95Top-end gasket failure compromises combustion sealing and power output—especially critical on high-compression 4-stroke builds. The COMETIC C7689 kit delivers factory-correct fitment for your YZ426F while employing multi-layered steel construction and...09340392- SKU:
- 09340392
- Availability:
- Ships Same Business Day
- Weight:
- 0.15 LBS
- BORE SIZE METRIC:
- 95.00 MM
- PRODUCT NAME:
- GASKET KIT
- UNITS:
- KIT
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- TOP END
$47.95Qty in Cart: 0Quantity:Price:$47.95Subtotal: -
COMETIC Bottom End Gasket Set - Honda C7010BE
COMETIC
$82.95A complete bottom end gasket set is essential when rebuilding your Honda engine—using OEM-equivalent seals and gaskets ensures proper oil containment, prevents coolant leaks, and maintains critical compression. COMETIC's U.S.-manufactured kits are...09344221- SKU:
- 09344221
- Availability:
- Ships Same Business Day
- Weight:
- 0.30 LBS
- BORE SIZE METRIC:
- 58.00 MM
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- MODEL:
- HI-PERFORMANCE
- PRODUCT NAME:
- GASKET KIT
- TYPE:
- BOTTOM END
$82.95Qty in Cart: 0Quantity:Price:$82.95Subtotal:
