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 Circlip 630-050SWL
MOOSE RACING
$4.95Circlips are critical retention components that keep shafts, bearings, and gears locked in place under high-stress conditions. The MOOSE RACING 630-050SWL delivers reliable holding power with precision engineering, ensuring your drivetrain components...09130071- SKU:
- 09130071
- Availability:
- Ships Same Business Day
- Weight:
- 0.02 LBS
- MATERIAL:
- STAINLESS STEEL
- RIDING STYLE:
- OFF-ROAD
- PRODUCT NAME:
- CIRCLIP
- APPLICATION:
- PISTON
- UNITS:
- SET
$4.95 -
MOOSE RACING Clutch Cylinder Guard 125/200 13-095
MOOSE RACING
$42.95Hydraulic clutch cylinders are vulnerable to chain slap and impact damage, especially in aggressive riding conditions. This guard protects your investment while maintaining clean aesthetics through precision CNC machining. The integrated knockdown bars...09500192- SKU:
- 09500192
- Availability:
- Ships Same Business Day
- Weight:
- 0.42 LBS
- TYPE:
- SLAVE CYLINDER
- COLOR/FINISH:
- ANODIZED
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- COLOR/FINISH:
- BLACK
- MATERIAL:
- ALUMINUM
- PRODUCT NAME:
- CASE SAVER
- RIDING STYLE:
- STREET
$42.95 -
MOOSE RACING Cylinder - Standard MSECW50008
MOOSE RACING
$487.95A worn or damaged cylinder directly compromises compression, power delivery, and engine reliability. The MOOSE RACING Standard Cylinder restores OEM performance with a precision-machined bore and a hardened nickel silicon carbide coating that resists...09310970- SKU:
- 09310970
- Availability:
- Ships Same Business Day
- Weight:
- 1.21 LBS
- CYLINDER BORE COATING:
- NICKEL-SILICON CARBIDE
- RIDING STYLE:
- ADVENTURE TOURING / DUAL-SPORT
- BORE SIZE METRIC:
- STANDARD
- COLOR/FINISH:
- GRAY
- CYLINDER DIAMETER:
- 88,00 MM
- CYLINDER DIAMETER METRIC:
- 88.00 MM
- ENGINE TYPE:
- 4-CYCLE
- MATERIAL:
- ALUMINUM
- UNITS:
- EACH
- MATERIAL:
- CAST
- PRODUCT NAME:
- CYLINDER
- DISPLACEMENT:
- 350 CC
- RIDING STYLE:
- OFF-ROAD
$487.95 -
MOOSE RACING Cylinder - Standard MSECW50012
MOOSE RACING
$402.95A worn or damaged cylinder directly compromises your engine's compression, power delivery, and reliability. This MOOSE RACING replacement restores OEM performance with a precision-honed bore and advanced plating that resists wear and dissipates heat more...09310971- SKU:
- 09310971
- Availability:
- Ships Same Business Day
- Weight:
- 2.51 LBS
- BORE SIZE METRIC:
- STANDARD
- CYLINDER BORE COATING:
- NICKEL-SILICON CARBIDE
- CYLINDER DIAMETER:
- 39,50 MM
- ENGINE TYPE:
- 2-CYCLE
- MATERIAL:
- ALUMINUM
- PRODUCT NAME:
- CYLINDER
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- EACH
- COLOR/FINISH:
- GRAY
- CYLINDER DIAMETER METRIC:
- 39.50 MM
- DISPLACEMENT:
- 50 CC
- MATERIAL:
- CAST
$402.95 -
MOOSE RACING Countershaft Sprocket Seal Kit - Yamaha 25-4020
MOOSE RACING
$22.95A worn countershaft sprocket seal compromises engine reliability and allows critical fluid loss—replacing it before failure occurs prevents costly internal damage and keeps your machine running at peak performance. This OEM-equivalent kit from MOOSE...09350445- SKU:
- 09350445
- Availability:
- Ships Same Business Day
- Weight:
- 0.15 LBS
- PRODUCT NAME:
- SEAL KIT
- APPLICATION:
- COUNTERSHAFT
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
$22.95Qty in Cart: 0Quantity:Price:$22.95Subtotal: -
MOOSE RACING Exhaust Gasket Kit 823155
MOOSE RACING
$21.87Exhaust gasket degradation is one of the most common sources of performance loss and emissions leaks in high-performance engines. A quality gasket kit ensures a perfect seal between exhaust manifolds and headers, preventing power-robbing blow-by and...09345336- SKU:
- 09345336
- Availability:
- Ships Same Business Day
- Weight:
- 0.05 LBS
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- PRODUCT NAME:
- GASKET KIT
- TYPE:
- EXHAUST
$21.87 -
MOOSE RACING Case Saver - RMZ250 0950-0520
MOOSE RACING
$27.95Engine case damage can sideline your RMZ250 and drain your wallet fast. This MOOSE RACING case saver replaces fragile OEM plastic with precision-engineered aluminum protection, keeping your engine safe during aggressive riding and occasional contact. You...09500520- SKU:
- 09500520
- Availability:
- Ships Same Business Day
- Weight:
- 0.21 LBS
- PRODUCT NAME:
- CASE SAVER
- TYPE:
- ENGINE
- BASE COLOR:
- SILVER
- MATERIAL:
- 6061 ALUMINUM
- COLOR/FINISH:
- ALUMINUM
- UNITS:
- EACH
- RIDING STYLE:
- OFF-ROAD
$27.95 -
MOOSE RACING Complete Motor Gasket Kit - TW200 808642
MOOSE RACING
$77.38A complete engine and transmission rebuild demands precision gaskets and seals that won't fail under load. The MOOSE RACING Complete Motor Gasket Kit eliminates the guesswork—and the cost of sourcing individual OEM components—by bundling everything you...09344785- SKU:
- 09344785
- Availability:
- Ships Same Business Day
- Weight:
- 0.25 LBS
- TYPE:
- ENGINE
- TYPE:
- COMPLETE
- UNITS:
- KIT
- PRODUCT NAME:
- GASKET
- RIDING STYLE:
- ADVENTURE TOURING / DUAL-SPORT
$77.38 -
MOOSE RACING Motor Seals - CR125R 822107
MOOSE RACING
$30.16Engine seal degradation is one of the most common causes of oil leakage and performance loss in two-stroke racing engines. MOOSE Racing Motor Seals deliver OEM-equivalent fit and durability at a fraction of the cost, allowing you to rebuild with...M822107- SKU:
- M822107
- Availability:
- Ships Same Business Day
- Weight:
- 0.15 LBS
- TYPE:
- OIL
- PRODUCT NAME:
- SEAL
- RIDING STYLE:
- OFF-ROAD
- APPLICATION:
- ENGINE
- UNITS:
- SET
$30.16 -
MOOSE RACING Motor Seals - CR250/500 822110
MOOSE RACING
$28.47Engine seals are critical wear items that directly impact compression, oil retention, and overall engine reliability—especially in high-performance applications where tolerances are tight. MOOSE Racing Motor Seals deliver OEM-equivalent fitment and...M822110- SKU:
- M822110
- Availability:
- Ships Same Business Day
- Weight:
- 0.15 LBS
- RIDING STYLE:
- OFF-ROAD
- APPLICATION:
- ENGINE
- TYPE:
- OIL
- UNITS:
- SET
- PRODUCT NAME:
- SEAL
$28.47 -
MOOSE RACING Motor Seals - CR250 822111
MOOSE RACING
$27.94A complete engine seal failure can sideline your CR250 at the worst possible moment. MOOSE Racing Motor Seals deliver OEM-equivalent performance at a fraction of OEM pricing, giving you the reliability to rebuild with confidence. Whether you're...M822111- SKU:
- M822111
- Availability:
- Ships Same Business Day
- Weight:
- 0.20 LBS
- RIDING STYLE:
- OFF-ROAD
- APPLICATION:
- ENGINE
- TYPE:
- OIL
- PRODUCT NAME:
- SEAL
- UNITS:
- SET
$27.94 -
MOOSE RACING Motor Seals - YZ125 822114
MOOSE RACING
$32.97When you're rebuilding a YZ125 engine or transmission, OEM seal kits command premium pricing—but MOOSE Racing Motor Seals deliver genuine OEM-equivalent quality at a fraction of the cost. Each set is engineered with high-tech materials for reliable...M822114- SKU:
- M822114
- Availability:
- Ships Same Business Day
- Weight:
- 0.15 LBS
- PRODUCT NAME:
- SEAL
- RIDING STYLE:
- OFF-ROAD
- APPLICATION:
- ENGINE
- TYPE:
- OIL
- UNITS:
- SET
$32.97 -
MOOSE RACING Top End Gasket - KX125 03 810430
MOOSE RACING
$38.67When you're rebuilding a KX125 top end, you need gaskets and seals that won't let you down—especially if you're running higher compression or replacing a piston. The MOOSE RACING Top End Gasket Set gives you every component required for a complete,...09340072- SKU:
- 09340072
- Availability:
- Ships Same Business Day
- Weight:
- 0.05 LBS
- ENGINE TYPE:
- 2-STROKE
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- TYPE:
- TOP END
- PRODUCT NAME:
- GASKET
$38.67 -
MOOSE RACING Top End Gasket - KLX/DRZ110 810415
MOOSE RACING
$38.72A top-end rebuild demands precision gaskets and seals that won't compromise engine integrity or cost you a fortune. The MOOSE RACING gasket set eliminates the need to source OEM parts at premium prices while delivering the same durability and accuracy...09340073- SKU:
- 09340073
- Availability:
- Ships Same Business Day
- Weight:
- 0.10 LBS
- RIDING STYLE:
- OFF-ROAD
- PRODUCT NAME:
- GASKET
- UNITS:
- KIT
- TYPE:
- TOP END
$38.72 -
MOOSE RACING Top End Gasket - DRZ125 810531
MOOSE RACING
$35.01A top-end rebuild demands precision gaskets and seals that won't fail under racing conditions or high-mileage riding. This Moose Racing gasket set eliminates the guesswork and expense of sourcing individual components, giving you every seal and gasket...09340074- SKU:
- 09340074
- Availability:
- Ships Same Business Day
- Weight:
- 0.10 LBS
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- TYPE:
- TOP END
- PRODUCT NAME:
- GASKET
$35.01 -
MOOSE RACING Motor Seals - YZ250 822122
MOOSE RACING
$35.65Engine and transmission seals are critical wear items that directly impact oil retention, performance, and longevity. OEM seals can cost significantly more, but MOOSE Racing delivers genuine replacement quality at a fraction of the price—without...M822122- SKU:
- M822122
- Availability:
- Ships Same Business Day
- Weight:
- 0.20 LBS
- APPLICATION:
- ENGINE
- TYPE:
- OIL
- UNITS:
- SET
- PRODUCT NAME:
- SEAL
- RIDING STYLE:
- OFF-ROAD
$35.65 -
MOOSE RACING Top End Gasket - YZ450F/YFZ 810677
MOOSE RACING
$68.81A top-end rebuild demands precision gaskets and seals that won't compromise your engine's integrity or your wallet. The MOOSE RACING gasket set delivers OEM-quality performance at a fraction of the cost, with every component engineered for accurate fit...09340081- SKU:
- 09340081
- Availability:
- Ships Same Business Day
- Weight:
- 0.15 LBS
- PRODUCT NAME:
- GASKET
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- TOP END
- UNITS:
- KIT
$68.81 -
VESRAH Exhaust Valve GG-4018-EX
VESRAH
$31.00A worn or damaged exhaust valve compromises combustion efficiency and can lead to power loss, increased emissions, and potential engine damage. The VESRAH Exhaust Valve GG-4018-EX delivers OEM-equivalent precision and durability, restoring your engine's...GG4018EX- SKU:
- GG4018EX
- Availability:
- Ships Same Business Day
- Weight:
- 0.05 LBS
- APPLICATION:
- EXHAUST
- HEAD DIAMETER:
- 24,70 MM
- LENGTH METRIC:
- 87.16 MM
- PRODUCT NAME:
- VALVE
- RIDING STYLE:
- ATV
- RIDING STYLE:
- OFF-ROAD
- STEM DIAMETER METRIC:
- 5.50 MM
- RIDING STYLE:
- ADVENTURE TOURING / DUAL-SPORT
- UNITS:
- EACH
- HEAD DIAMETER METRIC:
- 24.70 MM
- RIDING STYLE:
- STREET
$31.00 -
VESRAH Intake Valve GG-4018-IN
VESRAH
$19.67Maintaining OEM-equivalent valve performance is critical for engine reliability and consistent power delivery, especially in high-demand racing or rebuilt applications. The VESRAH Intake Valve GG-4018-IN delivers precision-manufactured construction that...GG4018IN- SKU:
- GG4018IN
- Availability:
- Ships Same Business Day
- Weight:
- 0.08 LBS
- APPLICATION:
- INTAKE
- RIDING STYLE:
- ADVENTURE TOURING / DUAL-SPORT
- RIDING STYLE:
- ATV
- UNITS:
- EACH
- HEAD DIAMETER METRIC:
- 29.00 MM
- RIDING STYLE:
- OFF-ROAD
- HEAD DIAMETER:
- 29,00 MM
- LENGTH METRIC:
- 89.09 MM
- PRODUCT NAME:
- VALVE
- STEM DIAMETER METRIC:
- 5.50 MM
- RIDING STYLE:
- STREET
$19.67 -
VESRAH Intake Valve GG-1023-IN
VESRAH
$20.33A worn or damaged intake valve compromises combustion efficiency, throttle response, and fuel economy. The VESRAH Intake Valve GG-1023-IN restores OEM-spec performance with precision-engineered materials that match factory tolerances and durability...09260398- SKU:
- 09260398
- Availability:
- Ships Same Business Day
- Weight:
- 0.05 LBS
- APPLICATION:
- INTAKE
- RIDING STYLE:
- ATV
- UNITS:
- EACH
- PRODUCT NAME:
- VALVE
- STEM DIAMETER METRIC:
- 5.00 MM
- HEAD DIAMETER:
- 23,00 MM
- HEAD DIAMETER METRIC:
- 23.00 MM
- LENGTH METRIC:
- 65.80 MM
- RIDING STYLE:
- OFF-ROAD
$20.33
