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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COMETIC Top End Gasket Kit - 79 mm - Kawasaki C3787
COMETIC
$84.95A failing head gasket will cost you power, reliability, and time on the track or in the shop. COMETIC's multi-layered steel design with Viton rubber coating distributes combustion pressure evenly across the sealing surface, reducing bore distortion and...09347856- SKU:
- 09347856
- Availability:
- Ships Same Business Day
- Weight:
- 0.10 LBS
$84.95 -
COMETIC Top End Gasket Kit - 96 mm - Honda C3801
COMETIC
$85.95A failed head gasket means catastrophic engine damage and costly downtime. The COMETIC Top End Gasket Kit delivers the sealing integrity and thermal management your high-output engine demands, whether you're running naturally aspirated or forced...09347859- SKU:
- 09347859
- Availability:
- Ships Same Business Day
- Weight:
- 0.15 LBS
$85.95 -
COMETIC Top End Gasket Kit - 97 mm - Yamaha C3813
COMETIC
$87.95A compromised top end gasket is one of the quickest ways to lose compression, power, and reliability. The COMETIC C3813 Top End Gasket Kit is engineered for high-output 4-stroke engines that demand precision sealing under extreme combustion pressures...09347863- SKU:
- 09347863
- Availability:
- Ships Same Business Day
- Weight:
- 0.15 LBS
$87.95 -
COMETIC Top End Gasket Kit - 47 mm - Kawasaki/Suzuki C7682
COMETIC
$28.95A failing top-end gasket can compromise combustion chamber sealing, reduce ring seal efficiency, and lead to catastrophic engine failure. The COMETIC C7682 kit delivers OEM-spec sealing with multi-layer steel construction and Viton rubber coating,...09347866- SKU:
- 09347866
- Availability:
- Ships Same Business Day
- Weight:
- 0.05 LBS
$28.95 -
COMETIC Top End Gasket Kit - 99 mm - Yamaha C3279-EST
COMETIC
$90.95A failing top-end gasket will cost you power and reliability—and on high-output 4-stroke engines running boost or chasing peak naturally aspirated performance, factory gaskets often can't handle the cylinder pressures. The COMETIC C3279-EST delivers the...09347829- SKU:
- 09347829
- Availability:
- Ships Same Business Day
- Weight:
- 0.20 LBS
$90.95 -
ACERBIS X-Power Kit - Black - Honda 2985460001
ACERBIS
$76.95Off-road riding exposes your engine casings to constant abuse from rocks, mud, and debris that can compromise critical engine components and lead to expensive damage. The ACERBIS X-Power Kit provides multi-point crankcase protection without the bulk,...09402209- SKU:
- 09402209
- Availability:
- Ships Same Business Day
- Weight:
- 1.45 LBS
$76.95 -
ACERBIS X-Power Kit - Red - Honda 2985460227
ACERBIS
$76.95Off-road riding exposes your engine casings to constant punishment—mud, rocks, and debris can compromise protective covers and create costly damage. The ACERBIS X-Power Kit shields critical engine components with durable crankcase protection, allowing...09402210- SKU:
- 09402210
- Availability:
- Ships Same Business Day
- Weight:
- 1.45 LBS
$76.95 -
Hot Cams Intake Camshaft Stage 2 Suzuki RM-Z250 2007-2009 2087-2IN
HOT CAMS
$294.95If you're running a stock RM-Z250 and want measurable performance gains without major engine modifications, the Hot Cams Stage 2 Intake Camshaft is the bolt-on solution. This CNC-machined upgrade delivers a solid 5–10% power increase across the RPM range...09251587- SKU:
- 09251587
- Availability:
- Ships Same Business Day
- Weight:
- 0.84 LBS
$294.95 -
Hot Cams Camshaft Stage 1 Honda CRF450R 2017-2020 HC00053
HOT CAMS
$377.95If you're running a stock Honda CRF450R, you're leaving power on the table. The Hot Cams Stage 1 Camshaft unlocks 5–10% additional horsepower and torque while sharpening throttle response across the entire RPM band—all without requiring a complete...09251593- SKU:
- 09251593
- Availability:
- Ships Same Business Day
- Weight:
- 1.05 LBS
$377.95 -
Hot Cams Camshaft Stage 2 Honda CRF450R 2017-2020 HC00054
HOT CAMS
$377.95If you're running a CRF450R and want measurable performance gains without a complete engine rebuild, the Hot Cams Stage 2 Camshaft delivers 5-10% power increases across the mid to top-end RPM range. This is a bolt-on upgrade that transforms throttle...09251594- SKU:
- 09251594
- Availability:
- Ships Same Business Day
- Weight:
- 1.07 LBS
$377.95 -
Hot Cams Camshaft Intake Stage 2 Yamaha YZ450F 2016-2019 HC00061
HOT CAMS
$318.95If you're running a 2016-2019 YZ450F and want measurable mid-to-top-end power without a complete engine rebuild, this Stage 2 intake camshaft delivers. The 5-10% horsepower gain translates to sharper throttle response and noticeably stronger pulling...09251595- SKU:
- 09251595
- Availability:
- Ships Same Business Day
- Weight:
- 1.00 LBS
$318.95 -
Hot Cams Stage 2 Exhaust Camshaft for Yamaha WR450F 2016-2018 HC00062
HOT CAMS
$318.95If you're running a WR450F and want meaningful mid-to-top-end power without a complete engine overhaul, this Stage 2 exhaust camshaft delivers a straightforward 5-10% horsepower increase with zero guesswork. Hot Cams engineered this specifically for...09251596- SKU:
- 09251596
- Availability:
- Ships Same Business Day
- Weight:
- 1.01 LBS
$318.95 -
Hot Cams Silent Camshaft Chain for KTM 250 SX-F 2005-2008 HC00114
HOT CAMS
$80.95A worn or inefficient camshaft chain directly impacts engine timing precision and creates excessive noise that signals internal stress. The Hot Cams Silent Camshaft Chain replaces OEM wear with heat-treated metallurgy and optimized sprocket engagement,...09251597- SKU:
- 09251597
- Availability:
- Ships Same Business Day
- Weight:
- 0.64 LBS
$80.95 -
Hot Cams Exhaust Camshaft Stage 1 & 2 Yamaha YZ250F 2019-2020 HC00122
HOT CAMS
$283.95If you're running a Yamaha YZ250F and want measurable gains in throttle response and midrange power, a quality exhaust camshaft is one of the highest-ROI upgrades available. This Hot Cams Stage 1 & 2 design delivers quicker acceleration off the bottom...09251600- SKU:
- 09251600
- Availability:
- Ships Same Business Day
- Weight:
- 0.98 LBS
$283.95 -
Hot Cams Stage 2 Intake Camshaft for Yamaha YZ250F 2019-2020 HC00125
HOT CAMS
$254.95If you're running a YZ250F and want tangible performance gains without a complete engine rebuild, the Hot Cams Stage 2 Intake Camshaft delivers measurable mid to top-end power increases where it matters most—on the track. This is a bolt-on upgrade that...09251601- SKU:
- 09251601
- Availability:
- Ships Same Business Day
- Weight:
- 0.85 LBS
$254.95 -
Hot Cams Camshaft Chain Roller Kit Honda CRF100F 2004-2009 2011-2013 HCDID25H090
HOT CAMS
$43.95A worn or failing camshaft chain roller can cause timing issues, increased engine noise, and catastrophic internal damage if it fails completely. The Hot Cams roller kit replaces critical wear points in your CRF100F's valve train with heat-treated...09251604- SKU:
- 09251604
- Availability:
- Ships Same Business Day
- Weight:
- 0.24 LBS
$43.95 -
JE PISTONS Piston Kit - 95.00 mm - Gas Gas | Husqvarna | KTM 393215
JE PISTONS
$329.99Whether you're rebuilding after a top-end overhaul or upgrading to tighter tolerances, a quality piston kit is non-negotiable for reliable power delivery and engine longevity. JE Pistons delivers the precision engineering your Gas Gas, Husqvarna, or KTM...09106852- SKU:
- 09106852
- Availability:
- Ships Same Business Day
- Weight:
- 1.10 LBS
$329.99 -
JE PISTONS Piston Kit - 95.00 mm - Kawasaki 395092
JE PISTONS
$432.99If you're pushing your Kawasaki engine to its limits, factory pistons won't cut it. JE Pistons' 95.00 mm kit is engineered with 2618-T6 forged aluminum—the same material trusted in professional racing—to handle sustained high RPM operation, improve...09106851- SKU:
- 09106851
- Availability:
- Ships Same Business Day
- Weight:
- 1.16 LBS
$432.99 -
VINTCO Crankshaft Assembly - Honda CR2017
VINTCO
$245.95A compromised crankshaft compromises everything downstream—power delivery, engine longevity, and reliability. The VINTCO CR2017 forged steel assembly restores full engine integrity with precision engineering that meets OEM tolerances, making it essential...09210947- SKU:
- 09210947
- Availability:
- Ships Same Business Day
- Weight:
- 4.88 LBS
$245.95 -
VINTCO Crankshaft Assembly - Kawasaki CR2019
VINTCO
$389.95A crankshaft is the backbone of your engine's reliability—any weakness here compromises power delivery and longevity. The VINTCO CR2019 is engineered to Kawasaki OEM specifications using heavy-duty forged steel, ensuring it handles high-RPM loads without...09210948- SKU:
- 09210948
- Availability:
- Ships Same Business Day
- Weight:
- 6.82 LBS
$389.95
