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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HOT RODS Crankshaft Kit CBK0167
HOT RODS
$927.95If you're building a high-performance engine or restoring a classic with serious power goals, a quality crankshaft assembly is non-negotiable. The HOT RODS Crankshaft Kit CBK0167 delivers factory-matched precision with the durability to handle aggressive...09210387- SKU:
- 09210387
- Availability:
- Ships Same Business Day
- Weight:
- 10.05 LBS
- TYPE:
- OEM
- PRODUCT NAME:
- CRANKSHAFT KIT
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
$927.95 -
HOT RODS Crankshaft 4021
HOT RODS
$515.95If you're building a long-stroke engine for your ATV, you need a crankshaft that's been engineered for the abuse that comes with high-performance riding. The HOT RODS Crankshaft 4021 arrives factory-assembled and trued to OEM specifications, eliminating...09210388- SKU:
- 09210388
- Availability:
- Ships Same Business Day
- Weight:
- 7.18 LBS
- COLOR/FINISH:
- STEEL
- PRODUCT NAME:
- CRANKSHAFT ASSEMBLY
- RIDING STYLE:
- OFF-ROAD
- MATERIAL:
- 4140 STEEL
- UNITS:
- ASSEMBLY
- DISPLACEMENT:
- 250 CC
- FEATURES:
- HEAVY DUTY CRANKSHAFT
- MODEL:
- 4-CYCLE
- STROKE LENGTH METRIC:
- 53.60 MM
- TYPE:
- OEM STROKE
$515.95 -
HOT RODS Crankshaft 4031
HOT RODS
$436.95If you're building a long-stroke engine for your ATV, you need a crankshaft engineered to handle the increased demands of extended stroke geometry. The HOT RODS Crankshaft 4031 arrives factory-assembled and pre-trued to OEM specifications, eliminating...09210389- SKU:
- 09210389
- Availability:
- Ships Same Business Day
- Weight:
- 4.06 LBS
- PRODUCT NAME:
- CRANKSHAFT ASSEMBLY
- STROKE LENGTH METRIC:
- 40.80 MM
- UNITS:
- ASSEMBLY
- COLOR/FINISH:
- STEEL
- DISPLACEMENT:
- 65 CC
- FEATURES:
- STANDARD CRANKSHAFT
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- OEM STROKE
- MATERIAL:
- 4140 STEEL
- MODEL:
- 2-CYCLE
$436.95 -
HOT RODS Crankshaft 4098
HOT RODS
$502.95If you're running a 400cc ATV and want to unlock genuine performance gains without extensive machine work, the HOT RODS Crankshaft 4098 delivers a factory-assembled, long-stroke solution that meets or surpasses OEM specifications. This complete assembly...09210244- SKU:
- 09210244
- Availability:
- Ships Same Business Day
- Weight:
- 9.45 LBS
- FEATURES:
- STANDARD CRANKSHAFT
- MODEL:
- 4-CYCLE
- TYPE:
- OEM STROKE
- DISPLACEMENT:
- 450 CC
- MATERIAL:
- 4140 STEEL
- UNITS:
- ASSEMBLY
- PRODUCT NAME:
- CRANKSHAFT ASSEMBLY
- COLOR/FINISH:
- STEEL
- RIDING STYLE:
- OFF-ROAD
- STROKE LENGTH METRIC:
- 60.80 MM
$502.95 -
HOT RODS Crankshaft - Stroker 4197
HOT RODS
$337.95If you're serious about maximizing displacement and low-end torque on your ATV, a stroker crank is the most cost-effective path to real power gains. The HOT RODS Stroker 4197 eliminates the machine work and custom fabrication typically required for...09210246- SKU:
- 09210246
- Availability:
- Ships Same Business Day
- Weight:
- 7.50 LBS
- PRODUCT NAME:
- CRANKSHAFT ASSEMBLY
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- STROKER
- DISPLACEMENT:
- 259 CC
- MODEL:
- 4-CYCLE
- STROKE LENGTH:
- 55,80 MM
- STROKE LENGTH METRIC:
- 55.80 MM
- COLOR/FINISH:
- STEEL
- FEATURES:
- HEAVY DUTY CRANKSHAFT
- MATERIAL:
- 4140 STEEL
- UNITS:
- ASSEMBLY
$337.95 -
HOT RODS Crankshaft Kit CBK0187
HOT RODS
$622.95The HOT RODS Crankshaft Kit CBK0187 is engineered for builders and racers who demand reliability under extreme conditions. Factory-assembled and true to OEM specifications, this complete crankshaft assembly arrives ready for installation—eliminating...09210504- SKU:
- 09210504
- Availability:
- Ships Same Business Day
- Weight:
- 6.75 LBS
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- PRODUCT NAME:
- CRANKSHAFT KIT
- TYPE:
- OEM
$622.95 -
HOT RODS Crankshaft Kit CBK0188
HOT RODS
$476.95If you're serious about maximizing displacement and power output, a stroker crankshaft assembly is one of the most effective modifications you can make. The HOT RODS CBK0188 arrives factory-assembled and pre-trued to OEM specifications, eliminating the...09210505- SKU:
- 09210505
- Availability:
- Ships Same Business Day
- Weight:
- 4.60 LBS
- UNITS:
- KIT
- RIDING STYLE:
- OFF-ROAD
- PRODUCT NAME:
- CRANKSHAFT KIT
- TYPE:
- OEM
$476.95 -
HOT RODS Crankshaft Kit CBK0191
HOT RODS
$768.95If you're building a high-performance engine or restoring a classic, a quality crankshaft assembly is non-negotiable—it's the foundation of reliable power delivery and longevity under boost or sustained RPM. The HOT RODS Crankshaft Kit CBK0191 arrives...09210521- SKU:
- 09210521
- Availability:
- Ships Same Business Day
- Weight:
- 13.40 LBS
- RIDING STYLE:
- OFF-ROAD
- PRODUCT NAME:
- CRANKSHAFT KIT
- TYPE:
- OEM
- UNITS:
- KIT
$768.95 -
HOT RODS Crankshaft Assembly 4053
HOT RODS
$247.95If you're serious about maximizing displacement and power output on your sport ATV, a long-stroke crankshaft assembly is one of the most effective modifications available—and the HOT RODS 4053 delivers that added cubic capacity without requiring...09210021- SKU:
- 09210021
- Availability:
- Ships Same Business Day
- Weight:
- 6.22 LBS
- DISPLACEMENT:
- 125 CC
- FEATURES:
- STANDARD CRANKSHAFT
- TYPE:
- OEM STROKE
- MODEL:
- 2-CYCLE
- PRODUCT NAME:
- CRANKSHAFT ASSEMBLY
- MATERIAL:
- 4140 STEEL
- UNITS:
- ASSEMBLY
- COLOR/FINISH:
- STEEL
- RIDING STYLE:
- OFF-ROAD
- STROKE LENGTH METRIC:
- 54.60 MM
$247.95 -
HOT RODS Crankshaft Assembly 4055
HOT RODS
$305.95If you're building a high-performance long-stroke engine for your ATV, the HOT RODS Crankshaft Assembly 4055 eliminates guesswork and machine work by delivering a complete, factory-assembled unit that meets or exceeds OEM specifications straight out of...09210023- SKU:
- 09210023
- Availability:
- Ships Same Business Day
- Weight:
- 6.36 LBS
- DISPLACEMENT:
- 125 CC
- PRODUCT NAME:
- CRANKSHAFT ASSEMBLY
- MODEL:
- 2-CYCLE
- COLOR/FINISH:
- STEEL
- FEATURES:
- STANDARD CRANKSHAFT
- RIDING STYLE:
- OFF-ROAD
- STROKE LENGTH METRIC:
- 54.60 MM
- TYPE:
- OEM STROKE
- MATERIAL:
- 4140 STEEL
- UNITS:
- ASSEMBLY
$305.95 -
HOT RODS Crankshaft Assembly - Stroker 4116
HOT RODS
$289.95A stroker crankshaft transforms your ATV's displacement and low-end torque without extensive machine work—delivering the cubic inches and power gains you need for serious trail performance. Hot Rods' engineered applications eliminate the guesswork by...09210025- SKU:
- 09210025
- Availability:
- Ships Same Business Day
- Weight:
- 4.60 LBS
- PRODUCT NAME:
- CRANKSHAFT ASSEMBLY
- STROKE LENGTH:
- 47,80 MM
- DISPLACEMENT:
- 85 CC TO 100 CC
- UNITS:
- ASSEMBLY
- COLOR/FINISH:
- STEEL
- FEATURES:
- STANDARD CRANKSHAFT
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- STROKER
- MATERIAL:
- 4140 STEEL
- MODEL:
- 2-CYCLE
- STROKE LENGTH METRIC:
- 47.80 MM
$289.95 -
HOT RODS Crankshaft 4061
HOT RODS
$901.95If you're building a long-stroke engine for your ATV, the HOT RODS Crankshaft 4061 eliminates guesswork by arriving factory-assembled, trued to OEM specs, and ready to bolt in. This complete assembly pairs the proven HOT RODS crankshaft with matching...09210037- SKU:
- 09210037
- Availability:
- Ships Same Business Day
- Weight:
- 21.89 LBS
- FEATURES:
- STANDARD CRANKSHAFT
- TYPE:
- OEM STROKE
- MATERIAL:
- 4140 STEEL
- RIDING STYLE:
- WATERCRAFT
- UNITS:
- ASSEMBLY
- DISPLACEMENT:
- 743 CC TO 781 CC
- MODEL:
- 2-CYCLE
- PRODUCT NAME:
- CRANKSHAFT ASSEMBLY
- COLOR/FINISH:
- STEEL
- STROKE LENGTH METRIC:
- 37.00 MM
$901.95 -
HOT RODS Crankshaft Kit CBK0053
HOT RODS
$423.95If you're building a high-performance engine or restoring a classic with increased displacement, the HOT RODS Crankshaft Kit CBK0053 delivers factory-matched reliability with measurable performance gains. This complete assembly arrives ready for...09210301- SKU:
- 09210301
- Availability:
- Ships Same Business Day
- Weight:
- 6.70 LBS
- UNITS:
- KIT
- RIDING STYLE:
- OFF-ROAD
- PRODUCT NAME:
- CRANKSHAFT KIT
- TYPE:
- OEM
$423.95 -
HOT RODS Crankshaft Kit CBK0002
HOT RODS
$397.95If you're building a high-performance engine or restoring a classic, the HOT RODS Crankshaft Kit CBK0002 delivers the reliability and precision that separates amateur builds from championship-level engines. This factory-assembled unit meets or exceeds...09210261- SKU:
- 09210261
- Availability:
- Ships Same Business Day
- Weight:
- 6.65 LBS
- PRODUCT NAME:
- CRANKSHAFT KIT
- TYPE:
- OEM
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
$397.95 -
COMETIC Top End Gasket Set - Suzuki C7778
COMETIC
$40.95If you're rebuilding your top end or pushing higher horsepower through forced induction, a quality gasket set is non-negotiable—factory gaskets often fail under sustained boost or aggressive tuning. The COMETIC C7778 uses multi-layered steel construction...C7778- SKU:
- C7778
- Availability:
- Ships Same Business Day
- Weight:
- 0.15 LBS
- PRODUCT NAME:
- GASKET KIT
- UNITS:
- KIT
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- TOP END
$40.95Qty in Cart: 0Quantity:Price:$40.95Subtotal: -
COMETIC Shift Shaft Seal OS236
COMETIC
$5.95Countershaft seal leaks are a common failure point that can compromise your transmission fluid integrity and lead to costly damage if left unaddressed. The COMETIC OS236 Shift Shaft Seal delivers OEM-quality sealing with materials engineered for the...09350875- SKU:
- 09350875
- Availability:
- Ships Same Business Day
- Weight:
- 0.10 LBS
- APPLICATION:
- SHIFTER SHAFT
- RIDING STYLE:
- STREET
- PRODUCT NAME:
- SEAL
- UNITS:
- EACH
$5.95 -
COMETIC Top End Gaskets - KTM C3606
COMETIC
$78.70A failed top end gasket can cost you race time, engine damage, and hundreds in repairs. COMETIC's C3606 gasket kit gives you OE-spec sealing with the durability trusted by professional racers worldwide. Install with confidence knowing your KTM top end is...09345414- SKU:
- 09345414
- Availability:
- Ships Same Business Day
- Weight:
- 0.16 LBS
- PRODUCT NAME:
- GASKET SET
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- TOP END
- UNITS:
- SET
$78.70 -
COMETIC Lower End Gaskets - KTM C3606BE
COMETIC
$121.75Maintaining proper compression and preventing fluid leakage is critical to reliable engine performance, especially in high-stress racing applications. COMETIC lower end gaskets are engineered to OEM specifications and trusted by professional teams...09345415- SKU:
- 09345415
- Availability:
- Ships Same Business Day
- Weight:
- 0.31 LBS
- PRODUCT NAME:
- GASKET SET
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- BOTTOM END
- UNITS:
- SET
$121.75 -
COMETIC Top End Gasket Set - Husqvarna C7734
COMETIC
$29.95A top-end gasket failure can sideline your build and compromise engine integrity. COMETIC's multi-layered steel construction with Viton rubber coating is engineered to handle the extreme pressures of modern high-output 4-strokes—both naturally aspirated...C7734- SKU:
- C7734
- Availability:
- Ships Same Business Day
- Weight:
- 0.05 LBS
- BORE SIZE METRIC:
- 54.00 MM
- THICKNESS IMPERIAL:
- 0,012'
- THICKNESS METRIC:
- 0.31 MM
- TYPE:
- TOP END
- UNITS:
- KIT
- PRODUCT NAME:
- GASKET KIT
- RIDING STYLE:
- OFF-ROAD
$29.95 -
COMETIC Top End Gasket Set - Honda C7757
COMETIC
$47.95A quality top-end gasket set is non-negotiable for engine longevity and performance consistency. The COMETIC C7757 delivers multi-layered steel construction with Viton rubber coating designed to handle the extreme pressures of high-output engines while...C7757- SKU:
- C7757
- Availability:
- Ships Same Business Day
- Weight:
- 0.10 LBS
- BORE SIZE METRIC:
- 54.00 MM
- THICKNESS IMPERIAL:
- 0,012'
- THICKNESS METRIC:
- 0.31 MM
- TYPE:
- TOP END
- PRODUCT NAME:
- GASKET KIT
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
$47.95Qty in Cart: 0Quantity:Price:$47.95Subtotal:
