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 - KX250F 808481
MOOSE RACING
$140.62A complete engine and transmission rebuild demands precision-fit gaskets and seals—factory tolerances won't tolerate improvisation. The MOOSE RACING Complete Motor Gasket Kit eliminates the guesswork...09341891- SKU:
- 09341891
- Availability:
- Ships Same Business Day
- Weight:
- 0.26 LBS
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- COMPLETE
- UNITS:
- KIT
- TYPE:
- ENGINE
- PRODUCT NAME:
- GASKET
$140.62 -
MOOSE RACING Motor Gasket Kit with Seal - KX250F 811481
MOOSE RACING
$193.69A complete engine and transmission rebuild demands precision-fit gaskets and seals that won't compromise your work or your wallet. MOOSE Racing delivers OEM-quality replacement seals at a fraction of...09341892- SKU:
- 09341892
- Availability:
- Ships Same Business Day
- Weight:
- 0.43 LBS
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- COMPLETE
- UNITS:
- KIT
- TYPE:
- ENGINE
- PRODUCT NAME:
- GASKET
$193.69 -
MOOSE RACING Top End Gasket Kit - KX450F 810482
MOOSE RACING
$88.86When you're rebuilding a KX450F top end, gasket quality directly impacts ring seal, combustion chamber integrity, and overall engine longevity. The MOOSE RACING Top End Gasket Kit eliminates the...09341893- SKU:
- 09341893
- Availability:
- Ships Same Business Day
- Weight:
- 0.18 LBS
- PRODUCT NAME:
- GASKET
- TYPE:
- TOP END
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
$88.86 -
MOOSE RACING Complete Motor Gasket Kit - KX450F 808482
MOOSE RACING
$172.14A complete engine and transmission rebuild demands gasket and seal components that match OEM specifications without the OEM price tag. This Moose Racing kit eliminates the guesswork of sourcing...09341894- SKU:
- 09341894
- Availability:
- Ships Same Business Day
- Weight:
- 0.29 LBS
- PRODUCT NAME:
- GASKET
- UNITS:
- KIT
- TYPE:
- ENGINE
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- COMPLETE
$172.14Qty in Cart: 0Quantity:Price:$172.14Subtotal: -
MOOSE RACING Motor Gasket Kit with Seal - KX450F 811482
MOOSE RACING
$196.71A complete engine and transmission rebuild demands precision-fit gaskets and seals—any compromise on fitment risks oil leaks, compression loss, and catastrophic failure. This Moose Racing kit...09341895- SKU:
- 09341895
- Availability:
- Ships Same Business Day
- Weight:
- 0.46 LBS
- PRODUCT NAME:
- GASKET
- TYPE:
- COMPLETE
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- TYPE:
- ENGINE
$196.71 -
MOOSE RACING Top End Gasket Kit - RMZ 450 810595
MOOSE RACING
$91.75A top-end rebuild demands precision—and OEM gasket sets come with OEM pricing. The MOOSE RACING Top End Gasket Kit delivers complete engine sealing at a fraction of the cost, with high-tech materials...09341896- SKU:
- 09341896
- Availability:
- Ships Same Business Day
- Weight:
- 0.17 LBS
- PRODUCT NAME:
- GASKET
- TYPE:
- TOP END
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
$91.75 -
MOOSE RACING Piston Ring - For 39.47 mm Piston MSE53010003950
MOOSE RACING
$20.95A worn or damaged piston ring compromises compression, increases blowby, and tanks your engine's efficiency and power output. MOOSE Racing's precision-engineered replacement ring restores proper...09120394- SKU:
- 09120394
- Availability:
- Ships Same Business Day
- Weight:
- 0.50 LBS
- RIDING STYLE:
- OFF-ROAD
- PISTON SIZE METRIC:
- STANDARD
- PRODUCT NAME:
- PISTON RING
- UNITS:
- EACH
$20.95Qty in Cart: 0Quantity:Price:$20.95Subtotal: -
MOOSE RACING Piston Ring - For 44.45 mm Piston MSE53010004450
MOOSE RACING
$23.95A worn or damaged piston ring compromises compression, increases blow-by, and tanks engine efficiency—costing you power and reliability on the track or street. MOOSE RACING's precision-engineered...09120395- SKU:
- 09120395
- Availability:
- Ships Same Business Day
- Weight:
- 0.01 LBS
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- EACH
- PRODUCT NAME:
- PISTON RING
- PISTON SIZE METRIC:
- STANDARD
$23.95 -
MOOSE RACING Piston Ring - For 44.97 mm Piston MSE53010004500
MOOSE RACING
$24.95A worn or damaged piston ring compromises combustion chamber seal, resulting in lost compression, increased blowby, and reduced power output. The MOOSE RACING Piston Ring MSE53010004500 restores...09120396- SKU:
- 09120396
- Availability:
- Ships Same Business Day
- Weight:
- 0.05 LBS
- UNITS:
- EACH
- RIDING STYLE:
- OFF-ROAD
- PRODUCT NAME:
- PISTON RING
- PISTON SIZE METRIC:
- STANDARD
$24.95 -
MOOSE RACING Piston Ring - For 47.45 mm Piston MSE53010004750
MOOSE RACING
$24.10A worn or damaged piston ring compromises compression, increases blow-by, and tanks your engine's efficiency and power output. The MOOSE RACING Piston Ring delivers OEM-quality performance to restore...09120397- SKU:
- 09120397
- Availability:
- Ships Same Business Day
- Weight:
- 0.01 LBS
- PRODUCT NAME:
- PISTON RING
- RIDING STYLE:
- OFF-ROAD
- PISTON SIZE METRIC:
- STANDARD
- UNITS:
- EACH
$24.10 -
MOOSE RACING Valve Shim - 9.48 x 1.45 - 5 pack MSE5PK948145
MOOSE RACING
$9.95Proper valve shim sizing is critical to maintaining correct valve clearance and preventing costly engine damage—and having a complete range on hand eliminates guesswork during valve train adjustments...09261933- SKU:
- 09261933
- Availability:
- Ships Same Business Day
- Weight:
- 0.05 LBS
- MATERIAL:
- ROLLED
- MATERIAL:
- STEEL
- RIDING STYLE:
- OFF-ROAD
- VALVE SHIM THICKNESS METRIC:
- 1.45 MM
- PRODUCT NAME:
- SHIM
- RIDING STYLE:
- SNOW
- RIDING STYLE:
- UTV
- RIDING STYLE:
- WATERCRAFT
- TYPE:
- VALVE
- UNITS:
- 5 PACK
- OUTSIDE DIAMETER METRIC:
- 9.48 MM
- RIDING STYLE:
- ADVENTURE TOURING / DUAL-SPORT
- RIDING STYLE:
- ATV
- RIDING STYLE:
- STREET
$9.95Qty in Cart: 0Quantity:Price:$9.95Subtotal: -
MOOSE RACING Valve Shim - 9.48 x 1.50 - 5 pack MSE5PK948150
MOOSE RACING
$9.95Maintaining precise valve clearances is critical to engine performance, reliability, and longevity. MOOSE Racing valve shims give you the exact sizing and durability needed to dial in your valve...09261934- SKU:
- 09261934
- Availability:
- Ships Same Business Day
- Weight:
- 0.05 LBS
- MATERIAL:
- ROLLED
- MATERIAL:
- STEEL
- RIDING STYLE:
- OFF-ROAD
- RIDING STYLE:
- ATV
- OUTSIDE DIAMETER METRIC:
- 9.48 MM
- RIDING STYLE:
- ADVENTURE TOURING / DUAL-SPORT
- RIDING STYLE:
- SNOW
- RIDING STYLE:
- STREET
- UNITS:
- 5 PACK
- VALVE SHIM THICKNESS METRIC:
- 1.50 MM
- PRODUCT NAME:
- SHIM
- RIDING STYLE:
- UTV
- RIDING STYLE:
- WATERCRAFT
- TYPE:
- VALVE
$9.95Qty in Cart: 0Quantity:Price:$9.95Subtotal: -
MOOSE RACING Valve Shim - 9.48 x 1.55 - 5 pack MSE5PK948155
MOOSE RACING
$9.95Valve shim maintenance is critical to keeping your engine's valve train operating at peak precision, and having the right sizes on hand eliminates guesswork during adjustment. These MOOSE RACING...09261935- SKU:
- 09261935
- Availability:
- Ships Same Business Day
- Weight:
- 0.05 LBS
- RIDING STYLE:
- OFF-ROAD
- RIDING STYLE:
- UTV
- RIDING STYLE:
- WATERCRAFT
- MATERIAL:
- ROLLED
- MATERIAL:
- STEEL
- OUTSIDE DIAMETER METRIC:
- 9.48 MM
- PRODUCT NAME:
- SHIM
- RIDING STYLE:
- ATV
- TYPE:
- VALVE
- VALVE SHIM THICKNESS METRIC:
- 1.55 MM
- RIDING STYLE:
- SNOW
- UNITS:
- 5 PACK
- RIDING STYLE:
- ADVENTURE TOURING / DUAL-SPORT
- RIDING STYLE:
- STREET
$9.95 -
MOOSE RACING Valve Shim - 9.48 x 1.70 - 5 pack MSE5PK948170
MOOSE RACING
$9.95Proper valve shim selection is critical for maintaining precise valve clearances and preventing costly engine damage. These MOOSE RACING shims eliminate guesswork during valve train maintenance,...09261938- SKU:
- 09261938
- Availability:
- Ships Same Business Day
- Weight:
- 0.05 LBS
- RIDING STYLE:
- UTV
- RIDING STYLE:
- WATERCRAFT
- RIDING STYLE:
- ATV
- TYPE:
- VALVE
- RIDING STYLE:
- ADVENTURE TOURING / DUAL-SPORT
- RIDING STYLE:
- STREET
- VALVE SHIM THICKNESS METRIC:
- 1.70 MM
- MATERIAL:
- ROLLED
- MATERIAL:
- STEEL
- OUTSIDE DIAMETER METRIC:
- 9.48 MM
- PRODUCT NAME:
- SHIM
- RIDING STYLE:
- OFF-ROAD
- RIDING STYLE:
- SNOW
- UNITS:
- 5 PACK
$9.95Qty in Cart: 0Quantity:Price:$9.95Subtotal: -
MOOSE RACING Valve Shim - 9.48 x 1.75 - 5 pack MSE5PK948175
MOOSE RACING
$9.95Precision valve shim work demands accuracy and reliability—this 5-pack ensures you have quality refills on hand when you need them. Forged from 4140 cold-rolled steel rather than sintered material,...09261939- SKU:
- 09261939
- Availability:
- Ships Same Business Day
- Weight:
- 0.05 LBS
- OUTSIDE DIAMETER METRIC:
- 9.48 MM
- PRODUCT NAME:
- SHIM
- RIDING STYLE:
- ADVENTURE TOURING / DUAL-SPORT
- RIDING STYLE:
- SNOW
- RIDING STYLE:
- STREET
- UNITS:
- 5 PACK
- MATERIAL:
- ROLLED
- MATERIAL:
- STEEL
- VALVE SHIM THICKNESS METRIC:
- 1.75 MM
- RIDING STYLE:
- ATV
- RIDING STYLE:
- OFF-ROAD
- RIDING STYLE:
- UTV
- RIDING STYLE:
- WATERCRAFT
- TYPE:
- VALVE
$9.95 -
MOOSE RACING Valve Shim - 9.48 x 1.80 - 5 pack MSE5PK948180
MOOSE RACING
$9.95Precision valve train maintenance demands reliable, durable shims that won't compromise your engine's performance. MOOSE RACING valve shims eliminate guesswork during valve lash adjustments—each shim...09261940- SKU:
- 09261940
- Availability:
- Ships Same Business Day
- Weight:
- 0.05 LBS
- RIDING STYLE:
- OFF-ROAD
- RIDING STYLE:
- UTV
- RIDING STYLE:
- WATERCRAFT
- RIDING STYLE:
- ATV
- TYPE:
- VALVE
- MATERIAL:
- ROLLED
- MATERIAL:
- STEEL
- OUTSIDE DIAMETER METRIC:
- 9.48 MM
- PRODUCT NAME:
- SHIM
- RIDING STYLE:
- SNOW
- UNITS:
- 5 PACK
- RIDING STYLE:
- ADVENTURE TOURING / DUAL-SPORT
- RIDING STYLE:
- STREET
- VALVE SHIM THICKNESS METRIC:
- 1.80 MM
$9.95 -
MOOSE RACING Valve Shim - 9.48 x 1.90 - 5 pack MSE5PK948190
MOOSE RACING
$9.95Valve shim replacement is an essential maintenance task that directly impacts engine performance, valve clearance, and longevity of your valve train. This 5-pack from MOOSE Racing gives you the...09261942- SKU:
- 09261942
- Availability:
- Ships Same Business Day
- Weight:
- 0.02 LBS
- PRODUCT NAME:
- SHIM
- RIDING STYLE:
- ADVENTURE TOURING / DUAL-SPORT
- RIDING STYLE:
- SNOW
- RIDING STYLE:
- STREET
- RIDING STYLE:
- UTV
- RIDING STYLE:
- WATERCRAFT
- UNITS:
- 5 PACK
- RIDING STYLE:
- ATV
- TYPE:
- VALVE
- MATERIAL:
- ROLLED
- MATERIAL:
- STEEL
- OUTSIDE DIAMETER METRIC:
- 9.48 MM
- RIDING STYLE:
- OFF-ROAD
- VALVE SHIM THICKNESS METRIC:
- 1.90 MM
$9.95 -
MOOSE RACING Crank Bearing - Husqvarna 24-1107
MOOSE RACING
$74.95A worn or damaged crankshaft bearing directly impacts engine reliability and power delivery on your 2-stroke. This MOOSE RACING kit restores proper crankshaft support and reduces parasitic friction...09240228- SKU:
- 09240228
- Availability:
- Ships Same Business Day
- Weight:
- 1.12 LBS
- RIDING STYLE:
- STREET
- UNITS:
- KIT
- APPLICATION:
- CRANKSHAFT
- PRODUCT NAME:
- BEARING
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- BALL
$74.95Qty in Cart: 0Quantity:Price:$74.95Subtotal: -
MOOSE RACING Crank Bearing - Husqvarna 24-1108
MOOSE RACING
$77.95A properly functioning crankshaft is the foundation of reliable 2-stroke performance, and worn bearings compromise both power delivery and engine longevity. The MOOSE RACING Crank Bearing kit...09240229- SKU:
- 09240229
- Availability:
- Ships Same Business Day
- Weight:
- 0.85 LBS
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- APPLICATION:
- CRANKSHAFT
- PRODUCT NAME:
- BEARING
- TYPE:
- BALL
- RIDING STYLE:
- STREET
$77.95 -
MOOSE RACING Crank Bearing - PW50 24-1061
MOOSE RACING
$41.95A worn crankshaft bearing is one of the fastest ways to lose power and reliability in a 2-stroke engine. The MOOSE RACING Crank Bearing Kit (24-1061) replaces both left and right bearings with...09240237- SKU:
- 09240237
- Availability:
- Ships Same Business Day
- Weight:
- 0.35 LBS
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- RIDING STYLE:
- STREET
- APPLICATION:
- CRANKSHAFT
- PRODUCT NAME:
- BEARING
- TYPE:
- BALL
$41.95
