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!
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- Price
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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 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 - 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 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
$82.95 -
COMETIC Bottom End Gasket Set - Honda C7116BE
COMETIC
$82.95A complete bottom-end gasket rebuild is only as reliable as its sealing components—compromised gaskets lead to oil leaks, contamination, and catastrophic engine failure. The COMETIC C7116BE Bottom End Gasket Set delivers OEM-equivalent sealing integrity...09344234- SKU:
- 09344234
- Availability:
- Ships Same Business Day
- Weight:
- 0.20 LBS
- MODEL:
- HI-PERFORMANCE
- UNITS:
- KIT
- PRODUCT NAME:
- GASKET KIT
- TYPE:
- BOTTOM END
- BORE SIZE METRIC:
- 68.50 MM
- RIDING STYLE:
- OFF-ROAD
$82.95 -
COMETIC Top End Gasket Set - Honda C7191
COMETIC
$54.95A compromised top end gasket set will cost you horsepower, reliability, and race time. The COMETIC C7191 delivers the seal integrity and thermal management your high-output engine demands, whether you're running naturally aspirated or forced induction...09344251- SKU:
- 09344251
- Availability:
- Ships Same Business Day
- Weight:
- 0.05 LBS
- BORE SIZE METRIC:
- 66.50 MM
- THICKNESS IMPERIAL:
- 0,012'
- UNITS:
- KIT
- THICKNESS METRIC:
- 0.31 MM
- PRODUCT NAME:
- GASKET KIT
- TYPE:
- TOP END
- RIDING STYLE:
- OFF-ROAD
$54.95 -
Hot Cams Cam Chain for Honda CRF250R 2010-2017 HC92RH2015106
HOT CAMS
$57.95A worn or stretched cam chain directly impacts valve timing, reducing power delivery and increasing engine wear. The HOT CAMS silent chain restores precision valve actuation while running quieter than OEM equipment—essential for racers chasing consistent...09250762- SKU:
- 09250762
- Availability:
- Ships Same Business Day
- Weight:
- 0.55 LBS
- BASE FINISH:
- RAW
- CHAIN SIZE:
- 92RH2015
- COLOR/FINISH:
- RAW
- UNITS:
- EACH
- MATERIAL:
- STEEL
- MODEL:
- SILENT
- RIDING STYLE:
- OFF-ROAD
- PRODUCT NAME:
- CHAIN
- TYPE:
- CAM
$57.95 -
Hot Cams Cam Chain for Honda CRF450R 2009-2016 HC96RH2015108
HOT CAMS
$58.95The cam chain is your engine's lifeline—wear it out, and you're looking at catastrophic internal damage. The HOT CAMS HC96RH2015108 replaces that vulnerable OEM component with heat-treated links and a silent chain design that reduces noise while...09250763- SKU:
- 09250763
- Availability:
- Ships Same Business Day
- Weight:
- 0.55 LBS
- MATERIAL:
- STEEL
- RIDING STYLE:
- OFF-ROAD
- CHAIN SIZE:
- 96RH2015
- PRODUCT NAME:
- CHAIN
- BASE FINISH:
- RAW
- COLOR/FINISH:
- RAW
- UNITS:
- EACH
- MODEL:
- SILENT
- TYPE:
- CAM
$58.95 -
Hot Cams Cam Chain for Yamaha YZ450F 2010-2020 HC98XRH2010122
HOT CAMS
$63.95The cam chain is the heartbeat of your YZ450F's valve train—a worn or failing unit will rob you of power, create mechanical noise, and risk catastrophic engine damage. The HOT CAMS HC98XRH2010122 delivers silent, reliable operation with heat-treated...09250764- SKU:
- 09250764
- Availability:
- Ships Same Business Day
- Weight:
- 0.50 LBS
- RIDING STYLE:
- OFF-ROAD
- BASE FINISH:
- RAW
- COLOR/FINISH:
- RAW
- UNITS:
- EACH
- MATERIAL:
- STEEL
- CHAIN SIZE:
- 98XRH2010
- MODEL:
- SILENT
- PRODUCT NAME:
- CHAIN
- TYPE:
- CAM
$63.95 -
Hot Cams Exhaust Camshaft for Suzuki RM-Z 450 2008-2014 2267-1E
HOT CAMS
$297.95The HOT CAMS Exhaust Camshaft 2267-1E is engineered to unlock measurable gains in torque and horsepower across your RM-Z 450's entire RPM range. Whether you're chasing low-end grunt or peak-RPM power on the track, this camshaft delivers the throttle...09250867- SKU:
- 09250867
- Availability:
- Ships Same Business Day
- Weight:
- 1.11 LBS
- APPLICATION:
- EXHAUST
- EXHAUST DURATION IMPERIAL:
- 238°
- EXHAUST LIFT METRIC:
- 9.70 MM
- TYPE:
- STAGE 1
- UNITS:
- EACH
- PRODUCT NAME:
- CAMSHAFT
- RIDING STYLE:
- OFF-ROAD
$297.95 -
Hot Cams Exhaust Camshaft for 2008-2014 Suzuki RM-Z450 2269-2E
HOT CAMS
$297.95If you're serious about maximizing your RM-Z450's performance on the track, your camshaft is where gains are made. The Hot Cams 2269-2E exhaust camshaft uses ITR (Improved Throttle Response) technology to sharpen throttle sensitivity across the entire...09250869- SKU:
- 09250869
- Availability:
- Ships Same Business Day
- Weight:
- 1.10 LBS
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- EACH
- EXHAUST LIFT METRIC:
- 9.70 MM
- APPLICATION:
- EXHAUST
- PRODUCT NAME:
- CAMSHAFT
- TYPE:
- STAGE 2
- EXHAUST DURATION IMPERIAL:
- 244°
$297.95 -
Hot Cams Exhaust Camshaft for Yamaha YZ250F 2014-2016 4271-1E
HOT CAMS
$321.95If you're serious about extracting maximum performance from your YZ250F, the Hot Cams Exhaust Camshaft 4271-1E is a foundational upgrade that rewires your engine's breathing characteristics. This Stage 1/2-configurable cam directly improves throttle...09250879- SKU:
- 09250879
- Availability:
- Ships Same Business Day
- Weight:
- 1.00 LBS
- APPLICATION:
- EXHAUST
- EXHAUST DURATION IMPERIAL:
- 246.7°
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- EACH
- EXHAUST LIFT METRIC:
- 8.59 MM
- PRODUCT NAME:
- CAMSHAFT
- TYPE:
- STAGE 1
$321.95 -
Hot Cams Exhaust Camshaft Yamaha YZ250F 2014-2016 4273-2E
HOT CAMS
$321.95If you're running a YZ250F in competition, camshaft selection directly impacts your power band characteristics and throttle response—two factors that separate competitive lap times from the field. The HOT CAMS 4273-2E exhaust camshaft is engineered to...09250881- SKU:
- 09250881
- Availability:
- Ships Same Business Day
- Weight:
- 1.05 LBS
- PRODUCT NAME:
- CAMSHAFT
- EXHAUST DURATION IMPERIAL:
- 249.5°
- RIDING STYLE:
- OFF-ROAD
- APPLICATION:
- EXHAUST
- EXHAUST LIFT METRIC:
- 8.76 MM
- TYPE:
- STAGE 2
- UNITS:
- EACH
$321.95 -
Hot Cams Exhaust Camshaft for Yamaha YZ450F 2014-2015 4281-2E
HOT CAMS
$286.95If you're serious about maximizing your YZ450F's performance, the Hot Cams Exhaust Camshaft 4281-2E is a direct bolt-in upgrade that delivers measurable gains across the entire RPM range. This Stage 1/Stage 2 design fundamentally improves throttle...09250885- SKU:
- 09250885
- Availability:
- Ships Same Business Day
- Weight:
- 1.05 LBS
- EXHAUST DURATION IMPERIAL:
- 249.4°
- PRODUCT NAME:
- CAMSHAFT
- RIDING STYLE:
- OFF-ROAD
- APPLICATION:
- EXHAUST
- EXHAUST LIFT METRIC:
- 9.14 MM
- UNITS:
- EACH
- TYPE:
- STAGE 2
$286.95 -
Hot Cams Cam Chain for Honda XR600R 1988-2000 HC82RH2010118
HOT CAMS
$89.95A worn or stock cam chain can compromise valve timing precision and introduce unwanted noise into your XR600R's powerband. The HOT CAMS HC82RH2010118 replaces the OEM chain with a heat-treated, silent design that maintains crisp valve actuation while...09250886- SKU:
- 09250886
- Availability:
- Ships Same Business Day
- Weight:
- 0.40 LBS
- CHAIN SIZE:
- 82RH2010
- COLOR/FINISH:
- RAW
- PRODUCT NAME:
- CHAIN
- UNITS:
- EACH
- MATERIAL:
- STEEL
- MODEL:
- SILENT
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- CAM
- RIDING STYLE:
- ATV
- BASE FINISH:
- RAW
- RIDING STYLE:
- STREET
$89.95 -
Hot Cams Cam Chain for Yamaha WR250F 2015-2021 YZ250F 2014-2022 YZ250FX 2015-2021 HC98XRH2010114
HOT CAMS
$44.95A worn or undersized cam chain compromises valve timing precision and engine reliability—especially critical on high-revving four-strokes like the YZ and WR platform. Hot Cams' heat-treated design delivers the strength and low-friction characteristics...09250887- SKU:
- 09250887
- Availability:
- Ships Same Business Day
- Weight:
- 0.51 LBS
- CHAIN SIZE:
- 98XRH2010
- PRODUCT NAME:
- CHAIN
- TYPE:
- CAM
- COLOR/FINISH:
- RAW
- UNITS:
- EACH
- MATERIAL:
- STEEL
- MODEL:
- SILENT
- RIDING STYLE:
- OFF-ROAD
- BASE FINISH:
- RAW
$44.95 -
Hot Cams Cam Chain 1999-2008 Honda TRX400EX HC82RH2010112
HOT CAMS
$85.95Experience unparalleled performance with the HOT CAMS Cam Chain HC82RH2010112, designed for superior durability and efficiency. Its exclusive heat-treated links ensure exceptional resistance to friction and impact, making it a reliable choice for...09250980- SKU:
- 09250980
- Availability:
- Ships Same Business Day
- Weight:
- 0.41 LBS
- CHAIN SIZE:
- 82RH2010
- COLOR/FINISH:
- RAW
- MATERIAL:
- STEEL
- RIDING STYLE:
- ATV
- UNITS:
- EACH
- PRODUCT NAME:
- CHAIN
- BASE FINISH:
- RAW
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- CAM
- MODEL:
- SILENT
$85.95 -
Hot Cams Cam Chain for Honda CRF150R 2007-2024 HC92RH2015096
HOT CAMS
$50.95Experience unparalleled performance with the HOT CAMS Cam Chain HC92RH2015096. Designed with precision and durability in mind, this silent chain features exclusive heat-treated links that enhance friction and impact resistance, making it the ideal choice...09250982- SKU:
- 09250982
- Availability:
- Ships Same Business Day
- Weight:
- 0.51 LBS
- PRODUCT NAME:
- CHAIN
- TYPE:
- CAM
- COLOR/FINISH:
- RAW
- UNITS:
- EACH
- CHAIN SIZE:
- 92RH2015
- MATERIAL:
- STEEL
- MODEL:
- SILENT
- RIDING STYLE:
- OFF-ROAD
- BASE FINISH:
- RAW
$50.95 -
Hot Cams Cam Chain for KTM 450 EXC-R 2008-2011 HC92RH2015110
HOT CAMS
$69.95Experience superior performance with the HOT CAMS Cam Chain HC92RH2015110. Designed with exclusive heat-treated links, this silent chain offers exceptional resistance to friction and impact, ensuring long-lasting durability. Engineered to surpass OEM...09250983- SKU:
- 09250983
- Availability:
- Ships Same Business Day
- Weight:
- 0.55 LBS
- COLOR/FINISH:
- RAW
- PRODUCT NAME:
- CHAIN
- UNITS:
- EACH
- CHAIN SIZE:
- 92RH2015
- MATERIAL:
- STEEL
- MODEL:
- SILENT
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- CAM
- BASE FINISH:
- RAW
- RIDING STYLE:
- STREET
$69.95
