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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On Sale
ATHENA Water Pump Gasket Kit - Yamaha P400485475002
ATHENA
MSRP: $37.95Now: $34.00Was: $37.95Seal leaks before they compromise your engine's cooling system and cost you race time. The ATHENA Water Pump Gasket Kit delivers OEM-grade sealing components in a single package, eliminating the frustration of sourcing gaskets and seals individually...09346084- SKU:
- 09346084
- Availability:
- Ships Same Business Day
- Weight:
- 0.10 LBS
- PRODUCT NAME:
- GASKET KIT
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- TYPE:
- WATER PUMP
MSRP: $37.95Now: $34.00Was: $37.95 -
On Sale
ATHENA Water Pump Gasket Kit - Yamaha P400485475003
ATHENA
MSRP: $38.95Now: $35.00Was: $38.95Water pump gasket failure is a common culprit behind coolant leaks and engine overheating—issues that can sideline your bike or damage your engine if left unchecked. The ATHENA Water Pump Gasket Kit provides all the OEM-specification seals and gaskets...09346085- SKU:
- 09346085
- Availability:
- Ships Same Business Day
- Weight:
- 0.20 LBS
- PRODUCT NAME:
- GASKET KIT
- TYPE:
- WATER PUMP
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
MSRP: $38.95Now: $35.00Was: $38.95 -
On Sale
ATHENA Water Pump Gasket Kit - Yamaha P400485475004
ATHENA
MSRP: $34.95Now: $31.00Was: $34.95A leaking water pump doesn't just waste coolant—it compromises engine temperature control and can lead to catastrophic overheating. The ATHENA Water Pump Gasket Kit delivers OEM-quality sealing surfaces to restore your cooling system's integrity without...09346086- SKU:
- 09346086
- Availability:
- Ships Same Business Day
- Weight:
- 0.15 LBS
- PRODUCT NAME:
- GASKET KIT
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- TYPE:
- WATER PUMP
MSRP: $34.95Now: $31.00Was: $34.95 -
On Sale
ATHENA Water Pump Gasket Kit - Yamaha P400485475006
ATHENA
MSRP: $37.95Now: $34.00Was: $37.95Coolant leaks and seal failures compromise engine reliability and performance—two things you can't afford on the track or in your build. The ATHENA Water Pump Gasket Kit provides OEM-quality sealing surfaces and precision-fit components to restore your...09346088- SKU:
- 09346088
- Availability:
- Ships Same Business Day
- Weight:
- 0.25 LBS
- PRODUCT NAME:
- GASKET KIT
- TYPE:
- WATER PUMP
- UNITS:
- KIT
- ENGINE TYPE:
- 4-STROKE
- RIDING STYLE:
- OFF-ROAD
MSRP: $37.95Now: $34.00Was: $37.95 -
On Sale
ATHENA Top End Gasket Kit - Honda P400210600304
ATHENA
MSRP: $38.95Now: $35.00Was: $38.95Engine reliability is everything when you're on the line, and a fresh top end gasket kit is your insurance policy before race day. The ATHENA P400210600304 gives you the flexibility to optimize your power delivery—run premium race fuel with elevated...09344815- SKU:
- 09344815
- Availability:
- Ships Same Business Day
- Weight:
- 0.10 LBS
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- TOP END
- UNITS:
- KIT
- PRODUCT NAME:
- GASKET KIT
MSRP: $38.95Now: $35.00Was: $38.95 -
On Sale
ATHENA Top End Gasket Kit - Yamaha P400485600004
ATHENA
MSRP: $12.95Now: $12.00Was: $12.95Whether you're prepping for race day or executing a midseason refresh, a quality top-end gasket kit is essential to maintaining cylinder head integrity and preventing catastrophic leaks. The ATHENA Top End Gasket Kit gives you the flexibility to tune...09344818- SKU:
- 09344818
- Availability:
- Ships Same Business Day
- Weight:
- 0.04 LBS
- PRODUCT NAME:
- GASKET KIT
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- TOP END
- UNITS:
- KIT
MSRP: $12.95Now: $12.00Was: $12.95 -
On Sale
ATHENA Top End Gasket Kit - Kawasaki P400250600068
ATHENA
MSRP: $82.95Now: $75.00Was: $82.95A fresh top-end gasket set is essential maintenance before race season or mid-season rebuilds, ensuring proper compression sealing and preventing costly leaks under high-load conditions. The ATHENA P400250600068 kit gives you the flexibility to run...09346354- SKU:
- 09346354
- Availability:
- Ships Same Business Day
- Weight:
- 0.36 LBS
- PRODUCT NAME:
- GASKET KIT
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- TYPE:
- TOP END
MSRP: $82.95Now: $75.00Was: $82.95 -
On Sale
ATHENA Complete Gasket Kit - Kawasaki P400250900068
ATHENA
MSRP: $224.95Now: $202.00Was: $224.95A complete gasket failure can leave you stranded or cost thousands in engine damage. The ATHENA Complete Gasket Kit delivers OEM-equivalent sealing integrity across all critical surfaces, ensuring your Kawasaki P400 engine maintains compression and...09346355- SKU:
- 09346355
- Availability:
- Ships Same Business Day
- Weight:
- 0.46 LBS
- PRODUCT NAME:
- GASKET KIT
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- COMPLETE
- UNITS:
- KIT
MSRP: $224.95Now: $202.00Was: $224.95 -
On Sale
ATHENA Complete Gasket Kit - KTM P400270900088
ATHENA
MSRP: $205.95Now: $185.00Was: $205.95A complete gasket kit is essential for engine longevity and reliability—whether you're rebuilding after a major service or protecting against future failures. The ATHENA Complete Gasket Kit delivers OEM-quality sealing across all critical engine...09346356- SKU:
- 09346356
- Availability:
- Ships Same Business Day
- Weight:
- 0.26 LBS
- UNITS:
- KIT
- PRODUCT NAME:
- GASKET KIT
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- COMPLETE
MSRP: $205.95Now: $185.00Was: $205.95 -
ACERBIS X-Power Cover Kit - Black - Yamaha 2780680001
ACERBIS
$76.95Off-road riding exposes your engine to constant battering from rocks, mud, and debris—damage that compromises performance and shortens component lifespan. The ACERBIS X-Power Cover Kit shields your crankcase and clutch cover with molded plastic...09401893- SKU:
- 09401893
- Availability:
- Ships Same Business Day
- Weight:
- 0.95 LBS
- MODEL:
- X-POWER
- PRODUCT NAME:
- COVER
- TYPE:
- ENGINE
- MATERIAL:
- PLASTIC
- PRODUCT NAME:
- COVER KIT
- COLOR/FINISH:
- BLACK
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
$76.95 -
ACERBIS X-Power Cover Kit - Black - Yamaha 2780690001
ACERBIS
$76.95Dirt, debris, and impact damage are constant threats to your engine's vulnerable crankcase and ignition covers during aggressive riding. The ACERBIS X-Power Cover Kit shields these critical components with molded, heat-resistant protection while...09401895- SKU:
- 09401895
- Availability:
- Ships Same Business Day
- Weight:
- 1.25 LBS
- MATERIAL:
- PLASTIC
- TYPE:
- ENGINE
- MODEL:
- X-POWER
- PRODUCT NAME:
- COVER
- PRODUCT NAME:
- COVER KIT
- COLOR/FINISH:
- BLACK
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
$76.95 -
ACERBIS X-Power Cover Kit - Blue - Yamaha 2780690211
ACERBIS
$76.95Protect your engine from the trail abuse that comes with serious riding. The ACERBIS X-Power Cover Kit shields your crankcase and ignition/clutch cover from dirt, debris, and impact damage while maintaining unrestricted access to critical service points...09401896- SKU:
- 09401896
- Availability:
- Ships Same Business Day
- Weight:
- 1.30 LBS
- MATERIAL:
- PLASTIC
- TYPE:
- ENGINE
- COLOR/FINISH:
- BLUE
- MODEL:
- X-POWER
- PRODUCT NAME:
- COVER
- UNITS:
- KIT
- PRODUCT NAME:
- COVER KIT
- RIDING STYLE:
- OFF-ROAD
$76.95 -
ACERBIS X-Power Cover Kit - Black - Yamaha 2791690001
ACERBIS
$76.95Protecting your engine from track debris and impact damage isn't optional—it's essential for reliability and longevity. The ACERBIS X-Power Cover Kit shields your crankcase and ignition/clutch cover with durable, heat-resistant material that won't...09401897- SKU:
- 09401897
- Availability:
- Ships Same Business Day
- Weight:
- 1.40 LBS
- COLOR/FINISH:
- BLACK
- PRODUCT NAME:
- COVER
- PRODUCT NAME:
- COVER KIT
- RIDING STYLE:
- OFF-ROAD
- MODEL:
- X-POWER
- UNITS:
- KIT
- MATERIAL:
- PLASTIC
- TYPE:
- ENGINE
$76.95 -
ACERBIS X-Power Cover Kit - Black - KTM/Husqvarna 2709760001
ACERBIS
$76.95Dirt and debris are inevitable when pushing your KTM or Husqvarna to the limit, but unprotected engine cases aren't. The ACERBIS X-Power Cover Kit shields your crankcase and ignition/clutch cover from impact and contamination while maintaining stock...09401757- SKU:
- 09401757
- Availability:
- Ships Same Business Day
- Weight:
- 1.20 LBS
- MATERIAL:
- PLASTIC
- MODEL:
- X-POWER
- RIDING STYLE:
- STREET
- TYPE:
- ENGINE
- COLOR/FINISH:
- BLACK
- PRODUCT NAME:
- COVER
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
$76.95 -
ACERBIS X-Power Cover Kit - Orange - KTM/Husqvarna 2709760237
ACERBIS
$69.95Dirt, rocks, and debris are inevitable when pushing your KTM or Husqvarna to the limit—and unprotected engine covers pay the price. The ACERBIS X-Power Cover Kit shields your crankcase and clutch cover from impact and contamination while maintaining...09401759- SKU:
- 09401759
- Availability:
- Ships Same Business Day
- Weight:
- 1.21 LBS
- MATERIAL:
- PLASTIC
- MODEL:
- X-POWER
- RIDING STYLE:
- STREET
- TYPE:
- ENGINE
- PRODUCT NAME:
- COVER
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- COLOR/FINISH:
- ORANGE
$69.95 -
JAGG OIL COOLERS Universal 10-Row Oil Cooler 3140
JAGG OIL COOLERS
$239.95Jagg Universal Oil Cooler Cores are the very same oil coolers that are used in high-quality Jagg kits, These units are perfect for the customizer, the fabricator, and the racer, Supplied as oil cooler only, Mounting hardware sold separately07130212- SKU:
- 07130212
- Availability:
- Ships Same Business Day
- Weight:
- 1.35 LBS
- MOUNTING POSITION:
- TOP
- PRODUCT NAME:
- OIL COOLER
- STYLE:
- 90°
- COLOR/FINISH:
- BLACK
- COLOR/FINISH:
- GLOSS
- MOUNTING STYLE:
- THREADED
- BASE COLOR:
- BLACK
- TYPE:
- 10-ROW
- UNITS:
- EACH
- BASE FINISH:
- POWDER-COATED
- RIDING STYLE:
- STREET
$239.95 -
JAGG OIL COOLERS Thermostat Service Kit AK4700-T
JAGG OIL COOLERS
$37.95Service kit to replace thermostat by-pass element in Jagg 4700 Offset Oil Filter Adapter07130216- SKU:
- 07130216
- Availability:
- Ships Same Business Day
- Weight:
- 0.10 LBS
- PRODUCT NAME:
- THERMOSTAT
- TYPE:
- OIL COOLER
- UNITS:
- KIT
- RIDING STYLE:
- STREET
$37.95 -
JAGG OIL COOLERS By-Pass Valve Service Kit SK4050-T
JAGG OIL COOLERS
$29.95Proper oil temperature management is critical for engine longevity and performance, especially in variable weather conditions. The JAGG SK4050-T by-pass valve gives you precise thermal control by allowing oil to bypass the cooler during cold starts or...07130219- SKU:
- 07130219
- Availability:
- Ships Same Business Day
- Weight:
- 0.05 LBS
- PRODUCT NAME:
- BYPASS VALVE
- TYPE:
- AUTOMATIC
- UNITS:
- KIT
- RIDING STYLE:
- STREET
$29.95 -
JAGG OIL COOLERS 180 Degree Preset Thermal Switch TS180
JAGG OIL COOLERS
$27.95This bi-metal disc type thermostat installs directly into any 1/8" NPT port and provides an automatic switch to turn on 12V electric fan at the set temperature07130220- SKU:
- 07130220
- Availability:
- Ships Same Business Day
- Weight:
- 0.10 LBS
- BASE COLOR:
- BLACK
- PRODUCT NAME:
- FAN SWITCH
- RIDING STYLE:
- STREET
- STYLE:
- 180°F
- TYPE:
- AUTOMATIC
- COLOR/FINISH:
- BLACK
- UNITS:
- EACH
$27.95 -
HOT RODS Seal Output Shaft OSK0010
HOT RODS
$27.95A leaking countershaft seal will compromise your transmission's integrity and lead to costly damage if left unaddressed. This HOT RODS complete kit eliminates guesswork by bundling everything you need to properly restore your seal in one purchase, saving...09350576- SKU:
- 09350576
- Availability:
- Ships Same Business Day
- Weight:
- 0.20 LBS
- APPLICATION:
- COUNTERSHAFT
- APPLICATION:
- TRANSMISSION
- PRODUCT NAME:
- SEAL
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
$27.95
