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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MOOSE RACING Motor Gasket Kit with Seal - RM125 811550
MOOSE RACING
$102.70A complete engine and transmission rebuild demands precision gaskets and seals that match OEM specifications—without the OEM price tag. This MOOSE RACING Motor Gasket Kit delivers genuine replacement seals and factory-engineered gaskets designed for...09340488- SKU:
- 09340488
- Availability:
- Ships Same Business Day
- Weight:
- 0.24 LBS
$102.70 -
MOOSE RACING Complete Motor Gasket Kit - TTR125 808640
MOOSE RACING
$73.01A complete engine and transmission rebuild demands precision gaskets and seals that won't compromise your work. The MOOSE RACING Complete Motor Gasket Kit delivers OEM-quality replacement seals and gaskets at a fraction of OEM pricing, allowing you to...09340489- SKU:
- 09340489
- Availability:
- Ships Same Business Day
- Weight:
- 0.15 LBS
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- COMPLETE
- UNITS:
- KIT
- PRODUCT NAME:
- GASKET
- TYPE:
- ENGINE
$73.01 -
MOOSE RACING Motor Gasket Kit with Seal - TTR125 811640
MOOSE RACING
$88.62A complete engine and transmission rebuild demands precision gaskets and seals that won't compromise your investment or performance. MOOSE Racing delivers OEM-equivalent fitment at a fraction of the cost, eliminating the need to source components...09340490- SKU:
- 09340490
- Availability:
- Ships Same Business Day
- Weight:
- 0.20 LBS
$88.62 -
MOOSE RACING Top End Gasket Kit - YZ125 810641
MOOSE RACING
$28.10A top-end rebuild demands precision gaskets and seals that won't compromise your engine's integrity or your wallet. The MOOSE RACING Top End Gasket Kit gives you OEM-quality components at a fraction of OEM pricing, so you can confidently reassemble your...09340491- SKU:
- 09340491
- Availability:
- Ships Same Business Day
- Weight:
- 0.07 LBS
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- TYPE:
- TOP END
- PRODUCT NAME:
- GASKET
$28.10 -
MOOSE RACING Slave Cylinder Rebuild Kit 18-6012
MOOSE RACING
$73.95A leaking slave cylinder doesn't just waste hydraulic fluid—it compromises clutch engagement and leaves you stranded. This MOOSE RACING rebuild kit gives you everything needed to restore a sealing slave cylinder without replacing the entire assembly,...09500897- SKU:
- 09500897
- Availability:
- Ships Same Business Day
- Weight:
- 0.12 LBS
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- RIDING STYLE:
- STREET
- PRODUCT NAME:
- REBUILD KIT
- TYPE:
- SLAVE CYLINDER
$73.95Qty in Cart: 0Quantity:Price:$73.95Subtotal: -
MOOSE RACING Slave Cylinder Rebuild Kit 18-6013
MOOSE RACING
$72.95A leaking slave cylinder compromises brake feel and can leave you stranded on track or trail. This MOOSE RACING rebuild kit gives you everything needed to restore a worn slave cylinder to like-new sealing performance, eliminating the guesswork and cost...09500898- SKU:
- 09500898
- Availability:
- Ships Same Business Day
- Weight:
- 0.15 LBS
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- PRODUCT NAME:
- REBUILD KIT
- TYPE:
- SLAVE CYLINDER
- RIDING STYLE:
- STREET
$72.95 -
MOOSE RACING Slave Cylinder Rebuild Kit - KTM 18-6004
MOOSE RACING
$44.95A leaking slave cylinder compromises clutch control and can strand you trackside or on the trail. This MOOSE RACING rebuild kit restores your hydraulic seal integrity with OEM-quality components, eliminating the need for a complete cylinder replacement...09500763- SKU:
- 09500763
- Availability:
- Ships Same Business Day
- Weight:
- 0.10 LBS
- TYPE:
- SLAVE CYLINDER
- RIDING STYLE:
- OFF-ROAD
- PRODUCT NAME:
- REBUILD KIT
- UNITS:
- KIT
$44.95 -
MOOSE RACING Slave Cylinder Rebuild Kit 18-6006
MOOSE RACING
$44.95A leaking slave cylinder compromises brake feel, reduces pedal responsiveness, and puts your safety at risk—whether you're on the track or the street. The MOOSE RACING Slave Cylinder Rebuild Kit 18-6006 gives you everything needed to restore proper...09500765- SKU:
- 09500765
- Availability:
- Ships Same Business Day
- Weight:
- 0.06 LBS
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- PRODUCT NAME:
- REBUILD KIT
- TYPE:
- SLAVE CYLINDER
$44.95 -
MOOSE RACING Slave Cylinder Rebuild Kit - KTM 18-6008
MOOSE RACING
$44.95A leaking slave cylinder compromises braking feel, reduces stopping power, and can leave you stranded on track or trail. This complete MOOSE RACING rebuild kit restores your hydraulic system to OEM specifications with factory-quality seals and...09500767- SKU:
- 09500767
- Availability:
- Ships Same Business Day
- Weight:
- 0.16 LBS
- PRODUCT NAME:
- REBUILD KIT
- TYPE:
- SLAVE CYLINDER
- UNITS:
- KIT
- RIDING STYLE:
- OFF-ROAD
$44.95 -
MOOSE RACING Slave Cylinder Rebuild Kit 18-6009
MOOSE RACING
$44.95A leaking slave cylinder compromises brake feel and can leave you stranded. This complete rebuild kit from MOOSE RACING provides all the OEM-specification seals and components needed to restore your slave cylinder to factory performance without replacing...09500768- SKU:
- 09500768
- Availability:
- Ships Same Business Day
- Weight:
- 0.06 LBS
- TYPE:
- SLAVE CYLINDER
- PRODUCT NAME:
- REBUILD KIT
- RIDING STYLE:
- ADVENTURE TOURING / DUAL-SPORT
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
$44.95 -
WSM Rotary Valve Gear 010-450
WSM
$45.26If your Sea-Doo's rotary valve isn't operating at peak efficiency, power delivery and throttle response suffer—and so does your watercraft's overall performance. The WSM Rotary Valve Gear 010-450 is a direct replacement engineered to restore precise...010450- SKU:
- 010450
- Availability:
- Ships Same Business Day
- Weight:
- 0.10 LBS
- UNITS:
- EACH
- PRODUCT NAME:
- GEAR
- RIDING STYLE:
- WATERCRAFT
- TYPE:
- ROTARY VALVE
$45.26 -
WSM Rotary Valve Shaft 010-455
WSM
$86.94The WSM Rotary Valve Shaft 010-455 is essential for maintaining precise intake timing and fuel delivery in your Sea-Doo engine. A worn or damaged rotary valve shaft compromises performance and can lead to costly engine damage if left unaddressed. This...010455- SKU:
- 010455
- Availability:
- Ships Same Business Day
- Weight:
- 0.40 LBS
- MATERIAL:
- STEEL
- PRODUCT NAME:
- SHAFT
- RIDING STYLE:
- WATERCRAFT
- TYPE:
- ROTARY VALVE
- UNITS:
- EACH
$86.94 -
WSM Top-End Rebuild Kit - Original Series - Standard 010-802-10
WSM
$247.87A top-end rebuild is essential maintenance for any high-performance engine, and the WSM Original Series kit delivers OEM-quality components at a fraction of full-engine rebuild costs. This comprehensive piston kit includes everything needed for a...01080210- SKU:
- 01080210
- Availability:
- Ships Same Business Day
- Weight:
- 2.60 LBS
- BORE - OVERSIZE METRIC:
- STANDARD
- PRODUCT NAME:
- REBUILD KIT
- UNITS:
- EACH
- BORE SIZE METRIC:
- 77.00 MM
- MODEL:
- ORIGINAL SERIES
- TYPE:
- TOP END
- BORE - OVERSIZE:
- STANDARD
- RIDING STYLE:
- WATERCRAFT
- PISTON MATERIAL:
- ALUMINUM
$247.87 -
WSM Top-End Rebuild Kit - Original Series - .50 mm 010-802-12
WSM
$247.87A top-end rebuild is fundamental to restoring your engine's compression, reliability, and power output—and the WSM Original Series kit gives you everything needed in one complete package. Whether you're refreshing a high-mileage engine or preparing for...01080212- SKU:
- 01080212
- Availability:
- Ships Same Business Day
- Weight:
- 2.85 LBS
- BORE SIZE METRIC:
- 77.50 MM
- PRODUCT NAME:
- REBUILD KIT
- BORE - OVERSIZE:
- +0,50 MM
- BORE - OVERSIZE METRIC:
- +0.50 MM
- MODEL:
- ORIGINAL SERIES
- PISTON MATERIAL:
- ALUMINUM
- RIDING STYLE:
- WATERCRAFT
- TYPE:
- TOP END
- UNITS:
- EACH
$247.87Qty in Cart: 0Quantity:Price:$247.87Subtotal: -
WSM Piston Kit - Kawasaki - Standard 010-810K
WSM
$82.17Your piston kit is the foundation of reliable power output and engine longevity. OEM-equivalent construction combined with advanced thermal management means you're getting professional-grade durability without compromising performance. Whether you're...010810- SKU:
- 010810
- Availability:
- Ships Same Business Day
- Weight:
- 0.81 LBS
- BORE - OVERSIZE:
- STANDARD
- BORE - OVERSIZE METRIC:
- STANDARD
- MODEL:
- ORIGINAL
- PRODUCT NAME:
- PISTON KIT
- UNITS:
- KIT
- RIDING STYLE:
- WATERCRAFT
- BORE SIZE METRIC:
- 76.00 MM
- PISTON MATERIAL:
- ALUMINUM
$82.17Qty in Cart: 0Quantity:Price:$82.17Subtotal: -
WSM Piston Kit - Kawasaki - +.25 mm 010-810-04K
WSM
$86.28When you're pushing your Kawasaki to the limit, stock pistons become your performance ceiling. The WSM Piston Kit delivers OEM-matching quality with critical upgrades—MOS2-coated skirts that actively dissipate heat while reducing friction, and specially...01081004- SKU:
- 01081004
- Availability:
- Ships Same Business Day
- Weight:
- 0.81 LBS
- BORE - OVERSIZE:
- +0,25 MM
- BORE - OVERSIZE METRIC:
- +0.25 MM
- BORE SIZE METRIC:
- 76.00 MM
- MODEL:
- ORIGINAL
- PRODUCT NAME:
- PISTON KIT
- PISTON MATERIAL:
- ALUMINUM
- RIDING STYLE:
- WATERCRAFT
- UNITS:
- KIT
$86.28 -
WSM Piston Kit - Kawasaki 650 - +.5 mm 010-810-05K
WSM
$86.28If you're rebuilding or upgrading your Kawasaki 650, piston quality directly impacts combustion efficiency, heat management, and engine longevity. The WSM Piston Kit delivers OEM-equivalent construction with purposeful upgrades—specifically the MOS2...01081005- SKU:
- 01081005
- Availability:
- Ships Same Business Day
- Weight:
- 0.81 LBS
- BORE - OVERSIZE METRIC:
- +0.50 MM
- RIDING STYLE:
- WATERCRAFT
- MODEL:
- ORIGINAL
- PISTON MATERIAL:
- ALUMINUM
- BORE SIZE METRIC:
- 76.00 MM
- PRODUCT NAME:
- PISTON KIT
- BORE - OVERSIZE:
- +0,50 MM
- UNITS:
- KIT
$86.28 -
WSM Top-End Rebuild Kit - Original Series - Standard 010-810-10
WSM
$252.25A top-end rebuild demands precision components that restore your engine to factory specifications or better. The WSM Top-End Rebuild Kit eliminates the guesswork of sourcing individual gaskets, rings, and bearings by bundling everything you need in one...01081010- SKU:
- 01081010
- Availability:
- Ships Same Business Day
- Weight:
- 2.55 LBS
- MODEL:
- ORIGINAL SERIES
- PISTON MATERIAL:
- ALUMINUM
- RIDING STYLE:
- WATERCRAFT
- BORE - OVERSIZE:
- STANDARD
- BORE - OVERSIZE METRIC:
- STANDARD
- BORE SIZE METRIC:
- 76.00 MM
- PRODUCT NAME:
- REBUILD KIT
- TYPE:
- TOP END
- UNITS:
- EACH
$252.25 -
WSM Top-End Rebuild Kit - Original Series - 1 mm 010-810-14
WSM
$252.25A complete top-end rebuild requires precision-matched components that work as an integrated system—not mismatched parts cobbled together. The WSM Original Series kit eliminates guesswork by pairing OEM-quality pistons, rings, and bearings with all...01081014- SKU:
- 01081014
- Availability:
- Ships Same Business Day
- Weight:
- 2.65 LBS
- TYPE:
- TOP END
- UNITS:
- EACH
- BORE - OVERSIZE:
- +1,00 MM
- BORE SIZE METRIC:
- 77.00 MM
- BORE - OVERSIZE METRIC:
- +1.00 MM
- PISTON MATERIAL:
- ALUMINUM
- MODEL:
- ORIGINAL SERIES
- PRODUCT NAME:
- REBUILD KIT
- RIDING STYLE:
- WATERCRAFT
$252.25Qty in Cart: 0Quantity:Price:$252.25Subtotal: -
WSM Piston Kit - Kawasaki 550 - +.5 mm 010-812-05K
WSM
$81.73If you're building or rebuilding a Kawasaki 550 engine, piston quality directly impacts reliability, power output, and engine longevity. WSM pistons are engineered to OEM or better standards with advanced coatings and hardened construction that reduce...01081205- SKU:
- 01081205
- Availability:
- Ships Same Business Day
- Weight:
- 0.70 LBS
- PRODUCT NAME:
- PISTON KIT
- BORE - OVERSIZE:
- +0,50 MM
- BORE - OVERSIZE METRIC:
- +0.50 MM
- BORE SIZE METRIC:
- 75.00 MM
- PISTON MATERIAL:
- ALUMINUM
- RIDING STYLE:
- WATERCRAFT
- UNITS:
- KIT
- MODEL:
- ORIGINAL
$81.73
