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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WINDEROSA Universal Gasket Kit 310113
WINDEROSA
$30.80A blown gasket can sideline your engine faster than you'd expect, compromising compression and reliability when you need it most. The WINDEROSA Universal Gasket Kit 310113 delivers OEM-quality...09346885- SKU:
- 09346885
- Availability:
- Ships Same Business Day
- Weight:
- 1.26 LBS
- UNITS:
- KIT
- PRODUCT NAME:
- GASKET KIT
$30.80 -
WINDEROSA Universal Gasket Kit - 12 x 18 310114
WINDEROSA
$32.08A reliable gasket kit is non-negotiable for any engine rebuild or top-end refresh. Engine sealing integrity directly impacts compression, prevents fluid leakage, and protects against...09346886- SKU:
- 09346886
- Availability:
- Ships Same Business Day
- Weight:
- 0.91 LBS
- UNITS:
- KIT
- PRODUCT NAME:
- GASKET KIT
$32.08 -
WINDEROSA Universal Gasket - Exhaust 310115
WINDEROSA
$22.38A quality exhaust gasket is critical to maintaining a reliable seal between engine components and preventing exhaust leaks that compromise performance and increase emissions. The WINDEROSA Universal...09346887- SKU:
- 09346887
- Availability:
- Ships Same Business Day
- Weight:
- 0.81 LBS
- RIDING STYLE:
- ADVENTURE TOURING / DUAL-SPORT
- RIDING STYLE:
- SNOW
- RIDING STYLE:
- UTV
- PRODUCT NAME:
- GASKET MATERIAL
- RIDING STYLE:
- STREET
- RIDING STYLE:
- WATERCRAFT
- RIDING STYLE:
- ATV
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- EACH
$22.38 -
WINDEROSA Gasket Kit - Standard Bore 810372
WINDEROSA
$83.58A complete gasket kit is fundamental to engine reliability—it seals critical junctions between engine components to prevent fluid leakage and maintain compression integrity. The WINDEROSA Gasket Kit...09346008- SKU:
- 09346008
- Availability:
- Ships Same Business Day
- Weight:
- 0.20 LBS
- BORE SIZE IMPERIAL:
- STANDARD
- PRODUCT NAME:
- GASKET KIT
- RIDING STYLE:
- STREET
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- CYLINDER
- UNITS:
- KIT
$83.58 -
WINDEROSA Standard Bore Gasket Kit 810670
WINDEROSA
$35.95When your engine demands a fresh start, a worn cylinder is no place to compromise. The WINDEROSA Standard Bore Gasket Kit delivers a complete, ready-to-install solution that restores OEM performance...09344049- SKU:
- 09344049
- Availability:
- Ships Same Business Day
- Weight:
- 0.20 LBS
- STYLE:
- STANDARD
- UNITS:
- KIT
- MATERIAL:
- NICKEL SILICON CARBIDE
- RIDING STYLE:
- OFF-ROAD
- PRODUCT NAME:
- GASKET KIT
- TYPE:
- TOP END
$35.95Qty in Cart: 0Quantity:Price:$35.95Subtotal: -
WINDEROSA Standard Bore Gasket Kit 810414
WINDEROSA
$25.87When your engine takes a beating on the track or trail, a worn cylinder demands replacement—not compromise. The WINDEROSA Standard Bore Gasket Kit delivers a complete, machine-ready solution that...09344053- SKU:
- 09344053
- Availability:
- Ships Same Business Day
- Weight:
- 0.10 LBS
- UNITS:
- KIT
- PRODUCT NAME:
- GASKET KIT
- TYPE:
- TOP END
- MATERIAL:
- NICKEL SILICON CARBIDE
- RIDING STYLE:
- OFF-ROAD
- STYLE:
- STANDARD
$25.87 -
WINDEROSA Carb Base Gasket - Mikuni 38M 619123
WINDEROSA
$11.70A worn or degraded carb base gasket will compromise fuel atomization and create air leaks that destabilize your jetting and idle characteristics. This WINDEROSA replacement gasket for the Mikuni 38M...09342620- SKU:
- 09342620
- Availability:
- Ships Same Business Day
- Weight:
- 0.04 LBS
- PRODUCT NAME:
- GASKET
- RIDING STYLE:
- WATERCRAFT
- STYLE:
- MIKUNI
- TYPE:
- CARBURETOR INTAKE
- BORE SIZE:
- 38,00 MM
- BORE SIZE METRIC:
- 38.00 MM
- MATERIAL:
- MICROPORE COMPOUND
- UNITS:
- 10 PACK
$11.70Qty in Cart: 0Quantity:Price:$11.70Subtotal: -
WINDEROSA Carb Base Gasket - Mikuni 40M 619124
WINDEROSA
$11.28A compromised carb base gasket will undermine fuel delivery precision and create vacuum leaks that rob your engine of performance. WINDEROSA's compressed micropore material resists fuel degradation...09342621- SKU:
- 09342621
- Availability:
- Ships Same Business Day
- Weight:
- 0.05 LBS
- RIDING STYLE:
- WATERCRAFT
- STYLE:
- MIKUNI
- PRODUCT NAME:
- GASKET
- UNITS:
- 10 PACK
- BORE SIZE:
- 40,00 MM
- TYPE:
- CARBURETOR INTAKE
- BORE SIZE METRIC:
- 40.00 MM
- MATERIAL:
- MICROPORE COMPOUND
$11.28 -
WINDEROSA Carb Base Gasket - Mikuni 44M 619125
WINDEROSA
$11.28A deteriorating carb base gasket will compromise your fuel delivery and create costly air leaks that kill performance. This WINDEROSA gasket is engineered from compressed micropore material to...09342622- SKU:
- 09342622
- Availability:
- Ships Same Business Day
- Weight:
- 0.05 LBS
- RIDING STYLE:
- WATERCRAFT
- STYLE:
- MIKUNI
- BORE SIZE:
- 44,00 MM
- BORE SIZE METRIC:
- 44.00 MM
- TYPE:
- CARBURETOR INTAKE
- PRODUCT NAME:
- GASKET
- UNITS:
- 10 PACK
- MATERIAL:
- MICROPORE COMPOUND
$11.28 -
WINDEROSA Complete Gasket Kit - Kawasaki 650 611104
WINDEROSA
$96.30A complete engine gasket failure can sideline your Kawasaki 650 and drain your wallet fast. This WINDEROSA complete gasket kit eliminates the guesswork and multiple orders by delivering every seal...PD810345- SKU:
- PD810345
- Availability:
- Ships Same Business Day
- Weight:
- 0.50 LBS
- TYPE:
- COMPLETE
- RIDING STYLE:
- WATERCRAFT
- PRODUCT NAME:
- GASKET SET
- UNITS:
- SET
$96.30 -
WINDEROSA Carb Base Gasket - Mikuni 46M 619126
WINDEROSA
$11.28A worn or degraded carb base gasket compromises fuel atomization and creates vacuum leaks that rob your engine of performance and reliability. The WINDEROSA 619126 is engineered from compressed...09342623- SKU:
- 09342623
- Availability:
- Ships Same Business Day
- Weight:
- 0.06 LBS
- BORE SIZE METRIC:
- 46.00 MM
- MATERIAL:
- MICROPORE COMPOUND
- TYPE:
- CARBURETOR INTAKE
- RIDING STYLE:
- WATERCRAFT
- STYLE:
- MIKUNI
- PRODUCT NAME:
- GASKET
- UNITS:
- 10 PACK
- BORE SIZE:
- 46,00 MM
$11.28 -
MOOSE RACING Washer/Snap Ring Counter Shaft 25-6016
MOOSE RACING
$34.95Front sprocket replacements demand precision fastening to maintain countershaft integrity and drivetrain reliability. MOOSE RACING's washer and snap ring kit eliminates the frustration of sourcing...09350495- SKU:
- 09350495
- Availability:
- Ships Same Business Day
- Weight:
- 0.30 LBS
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- 10 PACK
- APPLICATION:
- COUNTERSHAFT
- PRODUCT NAME:
- WASHER
- RIDING STYLE:
- STREET
$34.95 -
MOOSE RACING Valve Shim - 7.48 x 2.25 - 5 pack MSE5PK748225
MOOSE RACING
$9.95Proper valve clearance is critical to engine performance and longevity—too tight and you risk bent valves; too loose and you lose compression and efficiency. These MOOSE RACING valve shims give you...09261879- SKU:
- 09261879
- Availability:
- Ships Same Business Day
- Weight:
- 0.02 LBS
- OUTSIDE DIAMETER METRIC:
- 7.48 MM
- PRODUCT NAME:
- SHIM
- RIDING STYLE:
- ADVENTURE TOURING / DUAL-SPORT
- RIDING STYLE:
- SNOW
- RIDING STYLE:
- STREET
- UNITS:
- 5 PACK
- MATERIAL:
- ROLLED
- MATERIAL:
- STEEL
- RIDING STYLE:
- ATV
- RIDING STYLE:
- OFF-ROAD
- VALVE SHIM THICKNESS METRIC:
- 2.25 MM
- RIDING STYLE:
- UTV
- RIDING STYLE:
- WATERCRAFT
- TYPE:
- VALVE
$9.95 -
MOOSE RACING Valve Shim - 9.48 x 1.60 - 5 pack MSE5PK948160
MOOSE RACING
$9.95Maintaining precise valve clearances is critical to engine performance and longevity—even a few thousandths of an inch off can result in lost power, valve float, or premature wear. MOOSE Racing valve...09261936- SKU:
- 09261936
- Availability:
- Ships Same Business Day
- Weight:
- 0.02 LBS
- MATERIAL:
- STEEL
- RIDING STYLE:
- OFF-ROAD
- RIDING STYLE:
- UTV
- OUTSIDE DIAMETER METRIC:
- 9.48 MM
- RIDING STYLE:
- ADVENTURE TOURING / DUAL-SPORT
- RIDING STYLE:
- ATV
- RIDING STYLE:
- STREET
- MATERIAL:
- ROLLED
- PRODUCT NAME:
- SHIM
- RIDING STYLE:
- SNOW
- RIDING STYLE:
- WATERCRAFT
- TYPE:
- VALVE
- UNITS:
- 5 PACK
- VALVE SHIM THICKNESS METRIC:
- 1.60 MM
$9.95 -
MOOSE RACING Valve Shim - 9.48 x 2.90 - 5 pack MSE5PK948290
MOOSE RACING
$9.95Maintaining precise valve clearances is critical to engine performance and longevity, and having quality shims on hand ensures you can make accurate adjustments without delays. MOOSE RACING valve...09261962- SKU:
- 09261962
- Availability:
- Ships Same Business Day
- Weight:
- 0.02 LBS
- OUTSIDE DIAMETER METRIC:
- 9.48 MM
- RIDING STYLE:
- SNOW
- VALVE SHIM THICKNESS METRIC:
- 2.90 MM
- MATERIAL:
- ROLLED
- MATERIAL:
- STEEL
- RIDING STYLE:
- OFF-ROAD
- PRODUCT NAME:
- SHIM
- RIDING STYLE:
- UTV
- RIDING STYLE:
- WATERCRAFT
- TYPE:
- VALVE
- UNITS:
- 5 PACK
- RIDING STYLE:
- ADVENTURE TOURING / DUAL-SPORT
- RIDING STYLE:
- ATV
- RIDING STYLE:
- STREET
$9.95 -
MOOSE RACING Complete Motor Gasket Kit without Seals - CRF250R 8110030
MOOSE RACING
$228.07A complete engine rebuild requires gaskets that match OEM specifications without the OEM price tag. This MOOSE RACING kit delivers every gasket and o-ring needed for a full engine and transmission...09346453- SKU:
- 09346453
- Availability:
- Ships Same Business Day
- Weight:
- 0.45 LBS
- PRODUCT NAME:
- GASKET
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- COMPLETE
- UNITS:
- KIT
- TYPE:
- ENGINE
$228.07 -
MOOSE RACING Ignition Cover Gasket 816551
MOOSE RACING
$8.13A leaking ignition cover gasket compromises both engine performance and reliability—moisture and contaminants can infiltrate critical engine components. The MOOSE RACING Ignition Cover Gasket...09346576- SKU:
- 09346576
- Availability:
- Ships Same Business Day
- Weight:
- 0.11 LBS
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- EACH
- PRODUCT NAME:
- GASKET
- TYPE:
- IGNITION COVER
$8.13 -
MOOSE RACING Ignition Cover Gasket 816758
MOOSE RACING
$13.64A failing ignition cover gasket compromises your engine's seal integrity, inviting oil leakage and potential internal damage during high-RPM operation. The MOOSE RACING 816758 delivers OEM-equivalent...09346170- SKU:
- 09346170
- Availability:
- Ships Same Business Day
- Weight:
- 0.11 LBS
- ENGINE TYPE:
- 4-STROKE
- UNITS:
- EACH
- PRODUCT NAME:
- GASKET
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- IGNITION COVER
$13.64 -
MOOSE RACING Ring Set - For 78 mm Piston CP7800C
MOOSE RACING
$35.95A quality ring set is fundamental to engine reliability and performance—poor ring sealing directly compromises compression, power output, and oil control. The MOOSE RACING Ring Set for 78 mm pistons...09120239- SKU:
- 09120239
- Availability:
- Ships Same Business Day
- Weight:
- 0.02 LBS
- PRODUCT NAME:
- PISTON RING
- RIDING STYLE:
- OFF-ROAD
- PISTON SIZE METRIC:
- STANDARD
- UNITS:
- SET
$35.95Qty in Cart: 0Quantity:Price:$35.95Subtotal: -
MOOSE RACING Ring Set - For 66 mm Piston CP6600C
MOOSE RACING
$35.95A precision-engineered ring set designed specifically for 66 mm pistons, the MOOSE RACING CP6600C delivers the compression integrity and sealing performance critical for high-RPM racing applications...09120240- SKU:
- 09120240
- Availability:
- Ships Same Business Day
- Weight:
- 0.02 LBS
- UNITS:
- SET
- RIDING STYLE:
- OFF-ROAD
- PRODUCT NAME:
- PISTON RING
- PISTON SIZE METRIC:
- STANDARD
$35.95Qty in Cart: 0Quantity:Price:$35.95Subtotal:
