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 Inner Clutch Gasket 816300
MOOSE RACING
$33.38A leaking clutch gasket compromises both engine performance and reliability, leaving oil seepage that can damage adjacent components. The MOOSE RACING Inner Clutch Gasket 816300 delivers OEM-equivalent sealing with precision engineering and domestic...09346148- SKU:
- 09346148
- Availability:
- Ships Same Business Day
- Weight:
- 0.11 LBS
- PRODUCT NAME:
- GASKET
- UNITS:
- EACH
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- CLUTCH COVER
- RIDING STYLE:
- STREET
$33.38 -
MOOSE RACING Valve Shim - 7.48 x 2.10 - 5 pack MSE5PK748210
MOOSE RACING
$9.95Precision valve train maintenance demands reliable, durable shims that won't compromise your engine's calibration. These MOOSE RACING shims are forged from 4140 cold-rolled steel—not sintered—giving you superior strength and consistency across multiple...09261876- SKU:
- 09261876
- Availability:
- Ships Same Business Day
- Weight:
- 0.01 LBS
- PRODUCT NAME:
- SHIM
- RIDING STYLE:
- ADVENTURE TOURING / DUAL-SPORT
- RIDING STYLE:
- SNOW
- RIDING STYLE:
- STREET
- UNITS:
- 5 PACK
- MATERIAL:
- ROLLED
- MATERIAL:
- STEEL
- RIDING STYLE:
- UTV
- RIDING STYLE:
- WATERCRAFT
- TYPE:
- VALVE
- OUTSIDE DIAMETER METRIC:
- 7.48 MM
- RIDING STYLE:
- ATV
- RIDING STYLE:
- OFF-ROAD
- VALVE SHIM THICKNESS METRIC:
- 2.10 MM
$9.95 -
MOOSE RACING Outer Clutch Cover Gasket 817976
MOOSE RACING
$7.44A leaking clutch cover gasket compromises engine sealing and can lead to oil loss, contamination, and costly engine damage. The MOOSE RACING Outer Clutch Cover Gasket delivers OEM-equivalent sealing performance at a fraction of OEM pricing, using...09346183- SKU:
- 09346183
- Availability:
- Ships Same Business Day
- Weight:
- 0.11 LBS
- UNITS:
- EACH
- PRODUCT NAME:
- GASKET
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- CLUTCH COVER
$7.44 -
MOOSE RACING Ignition Cover Gasket 816222
MOOSE RACING
$17.79A leaking ignition cover gasket compromises engine sealing and can lead to oil seepage that damages surrounding components. The MOOSE RACING Ignition Cover Gasket (816222) delivers OEM-grade durability at a fraction of OEM pricing, ensuring a reliable...09346898- SKU:
- 09346898
- Availability:
- Ships Same Business Day
- Weight:
- 0.07 LBS
- TYPE:
- IGNITION COVER
- RIDING STYLE:
- OFF-ROAD
- PRODUCT NAME:
- GASKET
- UNITS:
- EACH
$17.79 -
MOOSE RACING Valve Cover Gasket - Kawasaki 817917
MOOSE RACING
$26.92A leaking valve cover gasket compromises engine sealing integrity and can lead to oil seepage that damages surrounding components. MOOSE RACING's OEM-quality gasket restores proper compression and prevents costly oil leaks on your Kawasaki engine. This...09346899- SKU:
- 09346899
- Availability:
- Ships Same Business Day
- Weight:
- 0.14 LBS
- TYPE:
- VALVE COVER
- RIDING STYLE:
- OFF-ROAD
- PRODUCT NAME:
- GASKET
- UNITS:
- EACH
$26.92 -
MOOSE RACING Motor Gasket Kit with Seal - RMZ450 811595
MOOSE RACING
$183.26A complete engine and transmission rebuild demands precision-fit gaskets and seals that won't compromise your work—or your wallet. The MOOSE RACING Motor Gasket Kit delivers OEM-quality replacement seals at a fraction of manufacturer pricing, letting you...09341898- SKU:
- 09341898
- Availability:
- Ships Same Business Day
- Weight:
- 0.80 LBS
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- COMPLETE
- TYPE:
- ENGINE
- PRODUCT NAME:
- GASKET
- UNITS:
- KIT
$183.26 -
MOOSE RACING Ignition Cover Gasket 816693
MOOSE RACING
$8.29A leaking ignition cover gasket compromises engine sealing and can lead to oil weeping that accelerates wear on surrounding components. The MOOSE RACING Ignition Cover Gasket delivers OEM-equivalent fitment and durability at a fraction of OEM pricing,...09341899- SKU:
- 09341899
- Availability:
- Ships Same Business Day
- Weight:
- 0.12 LBS
- TYPE:
- IGNITION COVER
- RIDING STYLE:
- OFF-ROAD
- PRODUCT NAME:
- GASKET
- UNITS:
- EACH
$8.29 -
MOOSE RACING Cylinder - Standard - KX250F MSE30012
MOOSE RACING
$402.95A worn or damaged cylinder directly undermines your KX250F's compression, throttle response, and overall reliability—especially if you're pushing hard on the track or trail. This MOOSE RACING replacement restores OEM performance specifications while...09310881- SKU:
- 09310881
- Availability:
- Ships Same Business Day
- Weight:
- 2.50 LBS
- RIDING STYLE:
- OFF-ROAD
- MATERIAL:
- CAST
- PRODUCT NAME:
- CYLINDER
- CYLINDER BORE COATING:
- NICKEL-SILICON CARBIDE
- MATERIAL:
- ALUMINUM
- UNITS:
- EACH
$402.95 -
MOOSE RACING Cylinder - Standard - YZ450F MSECW20012
MOOSE RACING
$427.95A worn or damaged cylinder directly compromises your YZ450F's compression, power delivery, and engine longevity. This MOOSE RACING replacement restores your bike to factory performance specs without modification or custom fabrication—just bolt it on and...09310882- SKU:
- 09310882
- Availability:
- Ships Same Business Day
- Weight:
- 3.35 LBS
- COLOR/FINISH:
- GRAY
- CYLINDER BORE COATING:
- NICKEL-SILICON CARBIDE
- CYLINDER DIAMETER METRIC:
- 97.00 MM
- RIDING STYLE:
- OFF-ROAD
- BORE SIZE METRIC:
- STANDARD
- MATERIAL:
- ALUMINUM
- UNITS:
- EACH
- CYLINDER DIAMETER:
- 97,00 MM
- ENGINE TYPE:
- 4-CYCLE
- MATERIAL:
- CAST
- PRODUCT NAME:
- CYLINDER
- DISPLACEMENT:
- 450 CC
$427.95 -
MOOSE RACING Top End Gasket Kit - RMZ250 810568
MOOSE RACING
$74.59A top-end rebuild demands precision gaskets and seals that won't compromise your engine's integrity or wallet. The MOOSE RACING Top End Gasket Kit delivers OEM-quality components at a fraction of OEM pricing, so you can confidently reassemble your RMZ250...09341269- SKU:
- 09341269
- Availability:
- Ships Same Business Day
- Weight:
- 0.16 LBS
- PRODUCT NAME:
- GASKET
- TYPE:
- TOP END
- UNITS:
- KIT
- RIDING STYLE:
- OFF-ROAD
$74.59 -
MOOSE RACING Complete Motor Gasket Kit - YZ250 808669
MOOSE RACING
$61.34A complete engine and transmission rebuild demands gasket and seal integrity—any compromise leads to oil leaks, contamination, and catastrophic failure. The MOOSE RACING Complete Motor Gasket Kit delivers OEM-quality replacement seals and gaskets at a...09341517- SKU:
- 09341517
- Availability:
- Ships Same Business Day
- Weight:
- 0.15 LBS
- TYPE:
- ENGINE
- PRODUCT NAME:
- GASKET
- UNITS:
- KIT
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- COMPLETE
$61.34 -
MOOSE RACING Ignition Cover Gasket 816677
MOOSE RACING
$11.22A leaking ignition cover gasket compromises engine sealing and invites oil contamination into critical systems. MOOSE RACING's OEM-equivalent gasket delivers the precise fit and durability you need to restore a proper seal at a fraction of OEM pricing...09341459- SKU:
- 09341459
- Availability:
- Ships Same Business Day
- Weight:
- 0.05 LBS
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- EACH
- PRODUCT NAME:
- GASKET
- TYPE:
- IGNITION COVER
$11.22 -
On Sale
TMV Camchain Tensioner 138361060
TMV
MSRP: $110.95Now: $71.00Was: $110.95A worn camchain tensioner compromises valve timing precision and can escalate into catastrophic engine damage if left unaddressed. The TMV Camchain Tensioner 138361060 restores optimal chain tension, ensuring reliable valve actuation and protecting your...09220177- SKU:
- 09220177
- Availability:
- Ships Same Business Day
- Weight:
- 0.20 LBS
- UNITS:
- EACH
- PRODUCT NAME:
- TENSIONER
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- CAM CHAIN
MSRP: $110.95Now: $71.00Was: $110.95 -
TMV Flywheel Weight 310FW1211
TMV
$152.95A flywheel is only as effective as its mass characteristics—and the TMV 310FW1211 delivers superior rotational inertia without sacrificing space or adding complexity. By using 303 stainless steel that's 15% denser than standard steel, this flywheel...09220085- SKU:
- 09220085
- Availability:
- Ships Same Business Day
- Weight:
- 0.91 LBS
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- EACH
- FEATURES:
- FLYWHEEL WEIGHT - 11 OZ.
- PRODUCT NAME:
- FLYWHEEL WEIGHT
- MATERIAL:
- 303 STAINLESS STEEL
$152.95 -
TMV Flywheel Weight 310FW1213
TMV
$152.95A heavier flywheel reduces engine rev hang and improves throttle response by increasing rotational inertia, giving you more control during aggressive driving and precision shifts. The TMV 310FW1213 uses 303 stainless steel—15% denser than standard...09220086- SKU:
- 09220086
- Availability:
- Ships Same Business Day
- Weight:
- 1.00 LBS
- FEATURES:
- FLYWHEEL WEIGHT - 13 OZ.
- UNITS:
- EACH
- PRODUCT NAME:
- FLYWHEEL WEIGHT
- RIDING STYLE:
- OFF-ROAD
- MATERIAL:
- 303 STAINLESS STEEL
$152.95 -
TMV Flywheel Weight 310FW1313
TMV
$181.95A heavier flywheel stabilizes engine operation and improves throttle response by storing rotational energy more efficiently. The TMV 310FW1313 uses 303 stainless steel—15% denser than standard steel—to pack maximum mass into a compact design without...09220089- SKU:
- 09220089
- Availability:
- Ships Same Business Day
- Weight:
- 0.85 LBS
- MATERIAL:
- 303 STAINLESS STEEL
- FEATURES:
- FLYWHEEL WEIGHT - 13 OZ.
- PRODUCT NAME:
- FLYWHEEL WEIGHT
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- EACH
$181.95 -
TMV Flywheel Weight 310FW5111
TMV
$152.95A heavier flywheel stabilizes engine RPM and improves throttle response, especially crucial for high-revving applications where rotational mass directly impacts power delivery. The TMV 310FW5111 achieves superior mass density using 303 stainless...09220091- SKU:
- 09220091
- Availability:
- Ships Same Business Day
- Weight:
- 0.80 LBS
- FEATURES:
- FLYWHEEL WEIGHT - 11 OZ.
- MATERIAL:
- 303 STAINLESS STEEL
- PRODUCT NAME:
- FLYWHEEL WEIGHT
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- EACH
$152.95 -
TMV Flywheel Weight 310FW5113
TMV
$152.95A heavier flywheel stores more rotational energy, delivering smoother power delivery and more predictable throttle response—critical for precision driving where consistency matters. The TMV 310FW5113 achieves this without bulk by using 303 stainless...09220092- SKU:
- 09220092
- Availability:
- Ships Same Business Day
- Weight:
- 1.10 LBS
- MATERIAL:
- 303 STAINLESS STEEL
- PRODUCT NAME:
- FLYWHEEL WEIGHT
- RIDING STYLE:
- OFF-ROAD
- FEATURES:
- FLYWHEEL WEIGHT - 13 OZ.
- UNITS:
- EACH
$152.95 -
TMV Flywheel Weight 310FW2213
TMV
$152.95A heavier flywheel increases engine inertia, delivering smoother power delivery and more predictable throttle response under acceleration and gear transitions. The TMV 310FW2213 achieves this performance advantage through precision machining and superior...09220101- SKU:
- 09220101
- Availability:
- Ships Same Business Day
- Weight:
- 0.91 LBS
- MATERIAL:
- 303 STAINLESS STEEL
- PRODUCT NAME:
- FLYWHEEL WEIGHT
- FEATURES:
- FLYWHEEL WEIGHT - 13 OZ.
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- EACH
$152.95 -
TMV Camchain Tensioner - Orange 138101012OR
TMV
$108.95Excessive timing chain slack is a silent killer—it allows destructive movement between your crankshaft and camshaft, risking catastrophic piston-to-valve contact and engine failure. The TMV Camchain Tensioner eliminates this dangerous play, maintaining...09251323- SKU:
- 09251323
- Availability:
- Ships Same Business Day
- Weight:
- 0.16 LBS
- BASE COLOR:
- ORANGE
- RIDING STYLE:
- OFF-ROAD
- PRODUCT NAME:
- CAM CHAIN TENSIONER
- UNITS:
- EACH
$108.95
