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 Sheet - 6 x 6 310101
WINDEROSA
$17.03A quality gasket sheet is non-negotiable for any serious engine builder or mechanic. WINDEROSA's universal gasket material gives you the flexibility to cut custom gaskets for virtually any application, eliminating costly downtime waiting for OEM...09346883- SKU:
- 09346883
- Availability:
- Ships Same Business Day
- Weight:
- 0.56 LBS
- RIDING STYLE:
- WATERCRAFT
- UNITS:
- KIT
- RIDING STYLE:
- OFF-ROAD
- RIDING STYLE:
- SNOW
- RIDING STYLE:
- UTV
- RIDING STYLE:
- ADVENTURE TOURING / DUAL-SPORT
- RIDING STYLE:
- ATV
- RIDING STYLE:
- STREET
- PRODUCT NAME:
- GASKET MATERIAL
$17.03 -
WINDEROSA Universal Gasket - 8 x 8 310102
WINDEROSA
$29.80A quality gasket is foundational to reliable engine sealing—leaks compromise performance and invite catastrophic engine damage. WINDEROSA universal gaskets deliver consistent compression across critical sealing surfaces, giving you the peace of mind that...09346884- SKU:
- 09346884
- Availability:
- Ships Same Business Day
- Weight:
- 0.66 LBS
- RIDING STYLE:
- ADVENTURE TOURING / DUAL-SPORT
- RIDING STYLE:
- SNOW
- RIDING STYLE:
- UTV
- RIDING STYLE:
- WATERCRAFT
- PRODUCT NAME:
- GASKET MATERIAL
- RIDING STYLE:
- ATV
- RIDING STYLE:
- STREET
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- EACH
$29.80 -
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 sealing across critical engine interfaces, eliminating leaks...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 contamination—all critical factors for consistent performance and...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 Gasket 310115 delivers consistent, long-lasting sealing...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 (810372) provides OEM-quality sealing surfaces across...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 without the downtime of machine work or re-plating...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
$35.95 -
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 restores your engine to OEM specifications without the...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 restores a reliable seal, ensuring your carburetor...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
$11.70 -
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 and thermal cycling, ensuring a reliable seal through...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
$11.28Qty in Cart: 0Quantity:Price:$11.28Subtotal: -
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 deliver reliable, long-lasting sealing on Mikuni 44M...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 you need in one package—bases, heads, intakes, and...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 micropore material to provide consistent, long-lasting...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 individual OEM fasteners and ensures you have the exact...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 precise adjustment capability without guesswork, and the...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 shims give you the accuracy and durability needed to...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 shims are forged from 4140 cold rolled steel—a material...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 teardown, letting you tackle the job with confidence...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 delivers OEM-quality sealing at a fraction of dealer pricing,...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 sealing performance with the reliability you need for...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
