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 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...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
$487.95Qty in Cart: 0Quantity:Price:$487.95Subtotal: -
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...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...09350445- SKU:
- 09350445
- Availability:
- Ships Same Business Day
- Weight:
- 0.15 LBS
- PRODUCT NAME:
- SEAL KIT
- APPLICATION:
- COUNTERSHAFT
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
$22.95 -
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...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...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...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...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...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...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...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...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...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...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...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...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 -
On Sale
VESRAH Exhaust Valve GG-4018-EX
VESRAH
MSRP: $31.00Now: $29.45Was: $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...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
MSRP: $31.00Now: $29.45Was: $31.00 -
On Sale
VESRAH Intake Valve GG-4018-IN
VESRAH
MSRP: $19.67Now: $18.69Was: $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...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
MSRP: $19.67Now: $18.69Was: $19.67 -
On Sale
VESRAH Intake Valve GG-1023-IN
VESRAH
MSRP: $20.33Now: $19.31Was: $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...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
MSRP: $20.33Now: $19.31Was: $20.33 -
On Sale
VESRAH Exhaust Valve GG-1023-EX
VESRAH
MSRP: $27.17Now: $25.81Was: $27.17A worn or damaged exhaust valve compromises combustion efficiency, reducing power output and increasing emissions. The VESRAH GG-1023-EX is precision-manufactured to OEM specifications, ensuring...09260049- SKU:
- 09260049
- Availability:
- Ships Same Business Day
- Weight:
- 0.06 LBS
- APPLICATION:
- EXHAUST
- HEAD DIAMETER:
- 20,00 MM
- LENGTH METRIC:
- 65.40 MM
- RIDING STYLE:
- ATV
- UNITS:
- EACH
- PRODUCT NAME:
- VALVE
- STEM DIAMETER METRIC:
- 5.00 MM
- HEAD DIAMETER METRIC:
- 20.00 MM
- RIDING STYLE:
- OFF-ROAD
MSRP: $27.17Now: $25.81Was: $27.17 -
On Sale
VESRAH Exhaust Gasket VE-3003
VESRAH
MSRP: $50.98Now: $48.43Was: $50.98Exhaust gasket failure leads to performance loss, increased emissions, and costly heat damage to surrounding components. The VESRAH VE-3003 delivers a reliable, cost-effective seal that maintains...VX3003- SKU:
- VX3003
- Availability:
- Ships Same Business Day
- Weight:
- 0.13 LBS
- PRODUCT NAME:
- GASKET
- RIDING STYLE:
- STREET
- RIDING STYLE:
- ADVENTURE TOURING / DUAL-SPORT
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- EXHAUST
- UNITS:
- 10 PACK
MSRP: $50.98Now: $48.43Was: $50.98
