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
-
MOOSE RACING Head Cover Gasket - KTM 819048
MOOSE RACING
$13.64Head cover gaskets are critical sealing components that prevent oil leakage and maintain engine integrity during operation. OEM replacements come at a premium price, but the MOOSE RACING Head Cover Gasket delivers genuine reliability at a fraction of the...09345903- SKU:
- 09345903
- Availability:
- Ships Same Business Day
- Weight:
- 0.15 LBS
- RIDING STYLE:
- STREET
- ENGINE TYPE:
- 4-STROKE
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- HEAD COVER
- UNITS:
- EACH
- MATERIAL:
- RUBBER
- PRODUCT NAME:
- GASKET
$13.64 -
MOOSE RACING Complete Motor Gasket Kit - YZ125 808636
MOOSE RACING
$54.00A complete engine and transmission rebuild demands gaskets and seals engineered for precision fit and lasting durability. This Moose Racing kit eliminates the guesswork of sourcing individual components, giving you every gasket, o-ring, and seal needed...M808636- SKU:
- M808636
- Availability:
- Ships Same Business Day
- Weight:
- 0.10 LBS
- PRODUCT NAME:
- GASKET
- UNITS:
- KIT
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- COMPLETE
- TYPE:
- ENGINE
$54.00 -
MOOSE RACING Complete Motor Gasket Kit - YZ125 808637
MOOSE RACING
$53.66A complete engine and transmission rebuild demands gaskets and seals that match OEM precision without the OEM price tag. The MOOSE RACING Complete Motor Gasket Kit gives you every gasket, o-ring, and valve seal needed for a full bottom-end refresh, so...M808637- SKU:
- M808637
- Availability:
- Ships Same Business Day
- Weight:
- 0.15 LBS
- PRODUCT NAME:
- GASKET
- UNITS:
- KIT
- TYPE:
- ENGINE
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- COMPLETE
$53.66 -
MOOSE RACING Complete Motor Gasket Kit - YZ125 808639
MOOSE RACING
$53.66A complete engine and transmission rebuild demands precision gaskets and seals that won't compromise your work—this Moose Racing kit delivers OEM-quality components at a fraction of the cost. Whether you're refreshing your YZ125 after a season of hard...M808639- SKU:
- M808639
- Availability:
- Ships Same Business Day
- Weight:
- 0.15 LBS
- TYPE:
- ENGINE
- PRODUCT NAME:
- GASKET
- UNITS:
- KIT
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- COMPLETE
$53.66 -
MOOSE RACING Complete Motor Gasket Kit - YZ250 808670
MOOSE RACING
$60.26A complete engine and transmission rebuild demands precision gaskets and seals that won't fail under race conditions or high-mileage wear. The MOOSE RACING Complete Motor Gasket Kit delivers OEM-quality replacement seals at a fraction of OEM pricing,...M808670- SKU:
- M808670
- Availability:
- Ships Same Business Day
- Weight:
- 0.18 LBS
- UNITS:
- KIT
- TYPE:
- ENGINE
- PRODUCT NAME:
- GASKET
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- COMPLETE
$60.26 -
MOOSE RACING Complete Motor Gasket Kit - YZ250F/WR250F 808671
MOOSE RACING
$109.78A complete engine and transmission rebuild demands precision gaskets and seals that won't compromise reliability or break your budget. This Moose Racing kit delivers OEM-quality components at a fraction of dealership pricing, allowing you to restore your...M808671- SKU:
- M808671
- Availability:
- Ships Same Business Day
- Weight:
- 0.21 LBS
- ENGINE TYPE:
- 4-STROKE
- PRODUCT NAME:
- GASKET
- UNITS:
- KIT
- TYPE:
- ENGINE
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- COMPLETE
$109.78 -
MOOSE RACING Complete Motor Gasket Kit - YZ400F/WR400F 808675
MOOSE RACING
$111.90A complete engine rebuild demands precision gaskets and seals that won't compromise reliability or performance. The MOOSE RACING Complete Motor Gasket Kit eliminates the guesswork and expense of sourcing individual components—you get every gasket,...M808675- SKU:
- M808675
- Availability:
- Ships Same Business Day
- Weight:
- 0.15 LBS
- PRODUCT NAME:
- GASKET
- UNITS:
- KIT
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- COMPLETE
- TYPE:
- ENGINE
$111.90Qty in Cart: 0Quantity:Price:$111.90Subtotal: -
MOOSE RACING Complete Motor Gasket Kit - Yamaha 808676
MOOSE RACING
$111.90A complete engine and transmission rebuild requires precision-fit gaskets and seals that can withstand demanding operating conditions. The MOOSE RACING Complete Motor Gasket Kit eliminates the headache of sourcing individual components by bundling...M808676- SKU:
- M808676
- Availability:
- Ships Same Business Day
- Weight:
- 0.20 LBS
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- COMPLETE
- TYPE:
- ENGINE
- PRODUCT NAME:
- GASKET
- UNITS:
- KIT
$111.90 -
MOOSE RACING Top End Gasket Kit - CR250R 810261
MOOSE RACING
$47.28When you're rebuilding a CR250R top end, you need gaskets and seals that match OEM precision without the OEM price tag. This Moose Racing kit gives you every component required for a complete top-end rebuild—from valve seals to base gaskets—manufactured...M810261- SKU:
- M810261
- Availability:
- Ships Same Business Day
- Weight:
- 0.10 LBS
- PRODUCT NAME:
- GASKET
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- TOP END
- UNITS:
- KIT
$47.28 -
MOOSE RACING Top End Gasket Kit - XR400 810265
MOOSE RACING
$55.47A top-end rebuild demands precision—and compromising on gaskets invites leaks, compression loss, and premature wear. The MOOSE RACING Top End Gasket Kit delivers OEM-quality seals and gaskets at a fraction of OEM pricing, so you can confidently refresh...M810265- SKU:
- M810265
- Availability:
- Ships Same Business Day
- Weight:
- 0.15 LBS
- TYPE:
- TOP END
- PRODUCT NAME:
- GASKET
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
$55.47 -
LA Sleeve Cylinder Sleeve 66.40mm Bore Suzuki RM250 2003 FL5494
LA SLEEVE
$148.95A worn or damaged cylinder sleeve kills engine performance and reliability. The LA SLEEVE FL5494 restores your RM250's cylinder integrity with precision engineering, delivering the power and durability you need for consistent track or trail performance...09310147- SKU:
- 09310147
- Availability:
- Ships Same Business Day
- Weight:
- 1.10 LBS
- COLOR/FINISH:
- CHROME
- PRODUCT NAME:
- CYLINDER SLEEVE
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- AC
- CYLINDER BORE COATING:
- CHROME-MOLY ALLOY
- BORE SIZE METRIC:
- 66.40 MM
- UNITS:
- EACH
$148.95 -
LA Sleeve Cylinder Sleeve 66.40mm Bore Suzuki RM250 2006-2008 FL5629
LA SLEEVE
$148.95A worn or damaged cylinder sleeve compromises compression, increases blow-by, and accelerates piston and ring wear—ultimately costing you race wins or reliability on the track. The LA SLEEVE FL5629 is a precision-engineered replacement that restores your...09310150- SKU:
- 09310150
- Availability:
- Ships Same Business Day
- Weight:
- 1.40 LBS
- COLOR/FINISH:
- CHROME
- PRODUCT NAME:
- CYLINDER SLEEVE
- RIDING STYLE:
- OFF-ROAD
- BORE SIZE METRIC:
- 66.40 MM
- UNITS:
- EACH
- CYLINDER BORE COATING:
- CHROME-MOLY ALLOY
- TYPE:
- AC
$148.95Qty in Cart: 0Quantity:Price:$148.95Subtotal: -
La Sleeve Sleeve and Piston Kit Yamaha YZ125 2002-2023 LAS-5476K
LA SLEEVE
$312.95The YZ125's top-end takes a beating in competition and trail riding, making a quality sleeve and piston kit essential for restoring compression, power delivery, and engine longevity. LA Sleeve's Moly2000 centrifugally-spun cylinder sleeve delivers...09310388- SKU:
- 09310388
- Availability:
- Ships Same Business Day
- Weight:
- 1.55 LBS
- MATERIAL:
- IRON
- RIDING STYLE:
- OFF-ROAD
- MATERIAL:
- CAST
- PRODUCT NAME:
- REBUILD KIT
- TYPE:
- CYLINDER
- UNITS:
- KIT
$312.95Qty in Cart: 0Quantity:Price:$312.95Subtotal: -
LA Sleeve YZ125 2005-2017 Sleeve and Piston Kit LAS-5533K-1
LA SLEEVE
$360.95Your YZ125's top-end is the foundation of its power delivery—and factory components wear fast under racing demands. The LA Sleeve Sleeve and Piston Kit delivers a complete, precision-matched rebuild solution that restores compression, improves ring seal,...09310389- SKU:
- 09310389
- Availability:
- Ships Same Business Day
- Weight:
- 1.80 LBS
- MATERIAL:
- IRON
- PRODUCT NAME:
- REBUILD KIT
- TYPE:
- CYLINDER
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- MATERIAL:
- CAST
$360.95Qty in Cart: 0Quantity:Price:$360.95Subtotal: -
LA Sleeve Sleeve and Piston Kit Honda CR250R 2002-2003 LAS-5477K
LA SLEEVE
$422.95When your Honda CR250R's top-end begins to wear, compression loss and power degradation follow quickly. The LA Sleeve Sleeve and Piston Kit restores—and exceeds—original performance by replacing worn components with precision-engineered parts designed...09310383- SKU:
- 09310383
- Availability:
- Ships Same Business Day
- Weight:
- 2.65 LBS
- MATERIAL:
- CAST
- PRODUCT NAME:
- REBUILD KIT
- TYPE:
- CYLINDER
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- MATERIAL:
- IRON
$422.95Qty in Cart: 0Quantity:Price:$422.95Subtotal: -
DEL WEST Intake Valve DW-KX450F-IV06
DEL WEST
$155.95When you're pushing your KX450F to its limits in high-RPM off-road conditions, valve reliability becomes non-negotiable. The DEL WEST Intake Valve DW-KX450F-IV06 is engineered to withstand the extreme thermal and mechanical demands of competition riding,...09261057- SKU:
- 09261057
- Availability:
- Ships Same Business Day
- Weight:
- 0.07 LBS
- APPLICATION:
- INTAKE
- PRODUCT NAME:
- VALVE
- RIDING STYLE:
- OFF-ROAD
- MATERIAL:
- TITANIUM
- UNITS:
- EACH
$155.95 -
MOOSE RACING Oil Seals 822370
MOOSE RACING
$40.60Engine and transmission rebuilds demand precision-fit seals that won't compromise reliability or longevity. MOOSE RACING Oil Seals deliver OEM-equivalent performance at a fraction of dealership pricing, letting you rebuild with confidence. This...09350947- SKU:
- 09350947
- Availability:
- Ships Same Business Day
- Weight:
- 0.15 LBS
- TYPE:
- OIL
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- SET
- APPLICATION:
- ENGINE
- PRODUCT NAME:
- SEAL
$40.60 -
MOOSE RACING Oil Seals 822372
MOOSE RACING
$46.08Engine and transmission seals are critical to maintaining proper oil containment and preventing costly leaks that compromise performance and reliability. When rebuilding or servicing your engine, OEM-equivalent seals are non-negotiable—and the MOOSE...09350948- SKU:
- 09350948
- Availability:
- Ships Same Business Day
- Weight:
- 0.15 LBS
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- OIL
- APPLICATION:
- ENGINE
- PRODUCT NAME:
- SEAL
- UNITS:
- SET
$46.08Qty in Cart: 0Quantity:Price:$46.08Subtotal: -
MOOSE RACING Engine Oil Seal Kit - Honda 822165
MOOSE RACING
$32.32Engine oil seals are critical wear items that prevent oil leakage and maintain proper lubrication pressure throughout your engine. A compromised seal can lead to oil loss, inadequate bearing protection, and potential engine damage. The MOOSE RACING...09351016- SKU:
- 09351016
- Availability:
- Ships Same Business Day
- Weight:
- 0.06 LBS
- PRODUCT NAME:
- SEAL KIT
- UNITS:
- KIT
- APPLICATION:
- ENGINE
- RIDING STYLE:
- ADVENTURE TOURING / DUAL-SPORT
- TYPE:
- OIL
$32.32 -
MOOSE RACING Engine Oil Seal Kit - Honda 822180
MOOSE RACING
$18.94Engine oil seals are critical wear items that prevent oil leakage and maintain proper lubrication throughout your engine. A failing seal kit leads to oil loss, reduced bearing protection, and potential internal engine damage—issues that compound quickly...09351017- SKU:
- 09351017
- Availability:
- Ships Same Business Day
- Weight:
- 0.06 LBS
- PRODUCT NAME:
- SEAL KIT
- UNITS:
- KIT
- APPLICATION:
- ENGINE
- RIDING STYLE:
- ADVENTURE TOURING / DUAL-SPORT
- TYPE:
- OIL
$18.94
