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 Complete Motor Gasket Kit - CR85R 808211
MOOSE RACING
$58.40A complete engine and transmission rebuild demands gasket and seal integrity—any compromise here leads to leaks, loss of compression, and catastrophic failure. The MOOSE RACING Complete Motor Gasket...09340265- SKU:
- 09340265
- Availability:
- Ships Same Business Day
- Weight:
- 0.16 LBS
- TYPE:
- ENGINE
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- COMPLETE
- PRODUCT NAME:
- GASKET
- UNITS:
- KIT
$58.40Qty in Cart: 0Quantity:Price:$58.40Subtotal: -
MOOSE RACING Motor Gasket Kit with Seal - YZ/WR400 811675
MOOSE RACING
$140.18A complete engine and transmission rebuild demands precision-fit gaskets and seals—and OEM replacements often come with OEM pricing. This Moose Racing kit delivers genuine OEM-quality oil seals...09341486- SKU:
- 09341486
- Availability:
- Ships Same Business Day
- Weight:
- 0.40 LBS
- TYPE:
- ENGINE
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- COMPLETE
- PRODUCT NAME:
- GASKET
- UNITS:
- KIT
$140.18Qty in Cart: 0Quantity:Price:$140.18Subtotal: -
MOOSE RACING Motor Gasket Kit with Seal - Husqvarna/KTM 811365
MOOSE RACING
$174.50A complete engine and transmission rebuild demands precision-fit gaskets and seals that won't compromise your work or your budget. The MOOSE RACING Motor Gasket Kit eliminates the guesswork and...09344789- SKU:
- 09344789
- Availability:
- Ships Same Business Day
- Weight:
- 0.50 LBS
- PRODUCT NAME:
- GASKET
- TYPE:
- ENGINE
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- COMPLETE
- UNITS:
- KIT
$174.50Qty in Cart: 0Quantity:Price:$174.50Subtotal: -
MOOSE RACING Complete Motor Gasket Kit - KDX200 808440
MOOSE RACING
$73.01A complete engine and transmission rebuild requires gaskets and seals that won't fail under stress. The MOOSE RACING Complete Motor Gasket Kit eliminates the guesswork by bundling every gasket,...M808440- SKU:
- M808440
- Availability:
- Ships Same Business Day
- Weight:
- 0.16 LBS
- TYPE:
- ENGINE
- PRODUCT NAME:
- GASKET
- RIDING STYLE:
- ADVENTURE TOURING / DUAL-SPORT
- UNITS:
- KIT
- TYPE:
- COMPLETE
$73.01 -
MOOSE RACING Complete Motor Gasket Kit - RM250 808593
MOOSE RACING
$112.43A complete engine and transmission rebuild requires precision-fit gaskets and seals that can handle sustained performance without leaking or failing. The MOOSE RACING Complete Motor Gasket Kit...09340974- SKU:
- 09340974
- Availability:
- Ships Same Business Day
- Weight:
- 0.21 LBS
- PRODUCT NAME:
- GASKET
- UNITS:
- KIT
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- COMPLETE
- TYPE:
- ENGINE
$112.43Qty in Cart: 0Quantity:Price:$112.43Subtotal: -
POWERSTANDS RACING Case Saver/Sprocket Cover - Blue 07-04150-25
POWERSTANDS RACING
$99.95A broken chain can transform a routine ride into catastrophic engine damage—and your stock plastic sprocket cover won't stop it. POWERSTANDS Racing's Case Saver replaces that flimsy OEM cover with a...09500788- SKU:
- 09500788
- Availability:
- Ships Same Business Day
- Weight:
- 0.85 LBS
- PRODUCT NAME:
- CASE SAVER
- PRODUCT NAME:
- SPROCKET COVER
- TYPE:
- ENGINE
- COLOR/FINISH:
- BLUE
- RIDING STYLE:
- STREET
- UNITS:
- EACH
- COLOR/FINISH:
- ANODIZED
- RIDING STYLE:
- OFF-ROAD
$99.95Qty in Cart: 0Quantity:Price:$99.95Subtotal: -
POWERSTANDS RACING Drain Plug 00-01946-24
POWERSTANDS RACING
$25.95A quality drain plug is essential for maintaining reliable engine oil circulation and preventing catastrophic fluid loss during high-performance driving. The POWERSTANDS RACING drain plug combines...09200108- SKU:
- 09200108
- Availability:
- Ships Same Business Day
- Weight:
- 0.21 LBS
- COLOR/FINISH:
- RED
- MATERIAL:
- ALUMINUM
- RIDING STYLE:
- STREET
- RIDING STYLE:
- UTV
- FEATURES:
- MAGNETIC
- PRODUCT NAME:
- BOLT
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- OIL DRAIN
- DIAMETER - THREAD SIZE METRIC:
- M12 X 1.50 X 15 MM
- RIDING STYLE:
- ATV
- UNITS:
- EACH
$25.95 -
On Sale
Pro Circuit Water Pump Cover with Impeller for Honda CRF450R 2019 WPH09450
PRO CIRCUIT
MSRP: $239.95Now: $215.96Was: $239.95Your Honda CRF450R's engine cooling efficiency directly impacts reliability and sustained performance under demanding conditions. The Pro Circuit Water Pump Cover replaces a vulnerable OEM component...09401180- SKU:
- 09401180
- Availability:
- Ships Same Business Day
- Weight:
- 0.36 LBS
- COLOR/FINISH:
- ANODIZED
- MATERIAL:
- BILLET ALUMINUM
- PRODUCT NAME:
- COVER
- RIDING STYLE:
- OFF-ROAD
- COLOR/FINISH:
- MACHINED
- TYPE:
- WATER PUMP
- UNITS:
- SET
MSRP: $239.95Now: $215.96Was: $239.95Qty in Cart: 0Quantity:Price:MSRP: $239.95Now: $215.96Was: $239.95Subtotal: -
On Sale
Pro Circuit Water Pump Cover with Impeller for 2004-2006 Suzuki RM-Z250 WPK04250
PRO CIRCUIT
MSRP: $239.95Now: $215.96Was: $239.95Keep your RM-Z250's engine running at peak operating temperature with the PRO CIRCUIT Water Pump Cover—a CNC-machined upgrade that directly improves cooling efficiency and reliability under demanding...09400464- SKU:
- 09400464
- Availability:
- Ships Same Business Day
- Weight:
- 0.55 LBS
- COLOR/FINISH:
- ANODIZED
- MATERIAL:
- BILLET ALUMINUM
- RIDING STYLE:
- OFF-ROAD
- PRODUCT NAME:
- COVER
- TYPE:
- WATER PUMP
- COLOR/FINISH:
- MACHINED
- UNITS:
- SET
MSRP: $239.95Now: $215.96Was: $239.95Qty in Cart: 0Quantity:Price:MSRP: $239.95Now: $215.96Was: $239.95Subtotal: -
MOOSE RACING Countershaft Sprocket Seal Kit - KTM 25-4001
MOOSE RACING
$27.95The countershaft sprocket seal is a critical wear component that directly impacts drivetrain reliability and longevity. Factory seals degrade under high heat and aggressive riding, leading to oil...09350428- SKU:
- 09350428
- Availability:
- Ships Same Business Day
- Weight:
- 0.14 LBS
- PRODUCT NAME:
- SEAL KIT
- UNITS:
- KIT
- APPLICATION:
- COUNTERSHAFT
- RIDING STYLE:
- STREET
- RIDING STYLE:
- OFF-ROAD
$27.95 -
MOOSE RACING Countershaft Sprocket Seal Kit - KTM 25-4003
MOOSE RACING
$25.95Your countershaft sprocket seal assembly endures constant rotational stress, heat, and contamination—premature wear here cascades into costly drivetrain damage. The MOOSE RACING Countershaft Sprocket...09350430- SKU:
- 09350430
- Availability:
- Ships Same Business Day
- Weight:
- 0.16 LBS
- RIDING STYLE:
- STREET
- PRODUCT NAME:
- SEAL KIT
- APPLICATION:
- COUNTERSHAFT
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
$25.95 -
MOOSE RACING Countershaft Sprocket Seal Kit - KTM 25-4006
MOOSE RACING
$23.95A worn countershaft seal kit compromises engine integrity and invites contamination into your transmission. The MOOSE RACING 25-4006 delivers OEM-quality sealing with upgraded components that extend...09350433- SKU:
- 09350433
- Availability:
- Ships Same Business Day
- Weight:
- 0.10 LBS
- APPLICATION:
- COUNTERSHAFT
- PRODUCT NAME:
- SEAL KIT
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
$23.95 -
MOOSE RACING Countershaft Sprocket Seal Kit - Yamaha 25-4023
MOOSE RACING
$22.95A worn countershaft sprocket seal compromises both performance and longevity by allowing contamination into critical drivetrain components. This MOOSE RACING kit delivers OEM-quality replacement...09350448- SKU:
- 09350448
- Availability:
- Ships Same Business Day
- Weight:
- 0.13 LBS
- APPLICATION:
- COUNTERSHAFT
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- PRODUCT NAME:
- SEAL KIT
$22.95 -
MOOSE RACING Motor Gasket Kit with Seal - KTM 811371
MOOSE RACING
$105.55A complete engine and transmission rebuild demands precision-fit gaskets and seals that won't compromise performance or longevity. MOOSE RACING delivers OEM-quality replacement seals at a fraction of...09345367- SKU:
- 09345367
- Availability:
- Ships Same Business Day
- Weight:
- 0.36 LBS
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- COMPLETE
- UNITS:
- KIT
- PRODUCT NAME:
- GASKET
- TYPE:
- ENGINE
$105.55Qty in Cart: 0Quantity:Price:$105.55Subtotal: -
MOOSE RACING Valve Shim - 8.90 x 2.28 - 5 pack MSE5PK890228
MOOSE RACING
$10.95Maintaining proper valve clearance is critical to engine performance, reliability, and longevity—and having the right shims on hand means you're never caught without the correct spec during a rebuild...09261919- SKU:
- 09261919
- Availability:
- Ships Same Business Day
- Weight:
- 0.02 LBS
- OUTSIDE DIAMETER METRIC:
- 8.90 MM
- RIDING STYLE:
- ATV
- TYPE:
- VALVE
- VALVE SHIM THICKNESS METRIC:
- 2.28 MM
- PRODUCT NAME:
- SHIM
- RIDING STYLE:
- ADVENTURE TOURING / DUAL-SPORT
- RIDING STYLE:
- STREET
- RIDING STYLE:
- UTV
- RIDING STYLE:
- WATERCRAFT
- UNITS:
- 5 PACK
- MATERIAL:
- ROLLED
- MATERIAL:
- STEEL
- RIDING STYLE:
- OFF-ROAD
- RIDING STYLE:
- SNOW
$10.95Qty in Cart: 0Quantity:Price:$10.95Subtotal: -
MOOSE RACING Valve Shim - 8.90 x 2.48 - 5 pack MSE5PK890248
MOOSE RACING
$10.95Valve shim maintenance separates meticulous engine builders from the rest. These forged 4140 steel shims enable precise valve clearance adjustments without guesswork, ensuring optimal valve train...09261924- SKU:
- 09261924
- Availability:
- Ships Same Business Day
- Weight:
- 0.15 LBS
- VALVE SHIM THICKNESS METRIC:
- 2.48 MM
- RIDING STYLE:
- ADVENTURE TOURING / DUAL-SPORT
- RIDING STYLE:
- ATV
- RIDING STYLE:
- STREET
- MATERIAL:
- ROLLED
- MATERIAL:
- STEEL
- RIDING STYLE:
- OFF-ROAD
- OUTSIDE DIAMETER METRIC:
- 8.90 MM
- PRODUCT NAME:
- SHIM
- RIDING STYLE:
- SNOW
- RIDING STYLE:
- UTV
- RIDING STYLE:
- WATERCRAFT
- TYPE:
- VALVE
- UNITS:
- 5 PACK
$10.95Qty in Cart: 0Quantity:Price:$10.95Subtotal: -
MOOSE RACING Head Cover Gasket - Yamaha 817944
MOOSE RACING
$26.58Valve cover gaskets fail silently—until oil starts seeping onto your engine bay. This Moose Racing head cover gasket delivers OEM-level sealing performance at a fraction of the dealer price, letting...09346181- SKU:
- 09346181
- Availability:
- Ships Same Business Day
- Weight:
- 0.15 LBS
- PRODUCT NAME:
- GASKET
- ENGINE TYPE:
- 4-STROKE
- TYPE:
- VALVE COVER
- UNITS:
- EACH
- MATERIAL:
- RUBBER
- RIDING STYLE:
- OFF-ROAD
$26.58 -
MOOSE RACING Ignition Cover Gasket 816177
MOOSE RACING
$11.14A worn or damaged ignition cover gasket compromises engine sealing and invites oil leakage around critical ignition components. The MOOSE RACING 816177 delivers OEM-quality sealing with the...09346934- SKU:
- 09346934
- Availability:
- Ships Same Business Day
- Weight:
- 0.07 LBS
- TYPE:
- IGNITION COVER
- RIDING STYLE:
- OFF-ROAD
- PRODUCT NAME:
- GASKET
- UNITS:
- EACH
$11.14 -
MOOSE RACING Cam Chain 250-8136
MOOSE RACING
$4.95A cam chain is critical to your engine's valve timing—if it stretches or fails, you're looking at bent valves and catastrophic damage. The MOOSE RACING 250-8136 is engineered with select steel alloys...09250819- SKU:
- 09250819
- Availability:
- Ships Same Business Day
- Weight:
- 0.65 LBS
- RIDING STYLE:
- OFF-ROAD
- BASE FINISH:
- RAW
- CHAIN SIZE:
- 82RH2015
- COLOR/FINISH:
- RAW
- RIDING STYLE:
- ADVENTURE TOURING / DUAL-SPORT
- UNITS:
- EACH
- MATERIAL:
- STEEL
- NUMBER OF LINKS:
- 124
- MODEL:
- SILENT
- PRODUCT NAME:
- CHAIN
- TYPE:
- CAM
$4.95Qty in Cart: 0Quantity:Price:$4.95Subtotal: -
MOOSE RACING Case Saver Guard - CRF150 CSG12
MOOSE RACING
$37.95Engine case damage during racing or aggressive riding can sideline your bike and drain your wallet fast. The MOOSE RACING Case Saver Guard protects your CRF150's vulnerable crankcase from impact...09500375- SKU:
- 09500375
- Availability:
- Ships Same Business Day
- Weight:
- 0.15 LBS
- COLOR/FINISH:
- BLACK
- RIDING STYLE:
- OFF-ROAD
- COLOR/FINISH:
- RED
- TYPE:
- CASE SAVER
- MATERIAL:
- NYLON
- PRODUCT NAME:
- GUARD
- UNITS:
- EACH
$37.95Qty in Cart: 0Quantity:Price:$37.95Subtotal:
