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!
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- Qty in Cart
- Quantity
- Price
- Subtotal
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LA Sleeve Cylinder Sleeve for Yamaha YFZ450 2004-2013 YA5495
LA SLEEVE
$127.95A worn cylinder compromises compression, power output, and fuel efficiency—especially critical on high-performance machines like the YFZ450. The LA SLEEVE Cylinder Sleeve YA5495 restores your engine to original specifications without requiring a full...09310070- SKU:
- 09310070
- Availability:
- Ships Same Business Day
- Weight:
- 1.59 LBS
- PRODUCT NAME:
- CYLINDER SLEEVE
- RIDING STYLE:
- OFF-ROAD
- COLOR/FINISH:
- ALUMINUM
- RIDING STYLE:
- ATV
- UNITS:
- EACH
- BORE SIZE METRIC:
- 95.00 MM
- CYLINDER BORE COATING:
- CHROME-MOLY ALLOY
- TYPE:
- AC
$127.95 -
Cylinder Works Standard Bore Cylinder Kit Kawasaki KX250F 2017-2019 30012-K02
CYLINDER WORKS
$704.95Your KX250F's stock cylinder will eventually wear—piston blow-by, lost compression, and increased friction are inevitable. The Cylinder Works Standard Bore Kit restores your engine to peak efficiency with OEM-matched specifications and Vertex pistons...09310727- SKU:
- 09310727
- Availability:
- Ships Same Business Day
- Weight:
- 3.25 LBS
- BORE SIZE METRIC:
- 77.00 MM
- STYLE:
- STANDARD
- ENGINE TYPE:
- 4-CYCLE
- CYLINDER DIAMETER METRIC:
- 77.00 MM
- RIDING STYLE:
- OFF-ROAD
- COMPRESSION RATIO IMPERIAL:
- 13.4:1
- CYLINDER BORE COATING:
- NICKEL-SILICON CARBIDE
- CYLINDER DIAMETER:
- 77,00 MM
- PRODUCT NAME:
- CYLINDER KIT
- UNITS:
- KIT
$704.95 -
Cylinder Works Kawasaki KX 250 F 2017-2019 Standard Bore High Compression Cylinder Kit 30012-K02HC
CYLINDER WORKS
$773.95Factory cylinder wear reduces compression and robs your KX 250 F of peak power delivery. This Cylinder Works kit restores lost performance with matched Vertex pistons and nickel silicon carbide plating that outlasts OEM components. Bolt-on installation...09310729- SKU:
- 09310729
- Availability:
- Ships Same Business Day
- Weight:
- 3.25 LBS
- CYLINDER DIAMETER:
- 77,00 MM
- ENGINE TYPE:
- 4-CYCLE
- PRODUCT NAME:
- CYLINDER KIT
- CYLINDER DIAMETER METRIC:
- 77.00 MM
- STYLE:
- STANDARD
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- BORE SIZE METRIC:
- 77.00 MM
- COMPRESSION RATIO IMPERIAL:
- 14.3:1
$773.95 -
MOOSE RACING Case Saver CR125R 01-161
MOOSE RACING
$23.95Engine case damage can sideline your CR125R and derail your season. The MOOSE RACING Case Saver replaces fragile OEM plastic guards with robust 6061 aluminum protection that actually looks the part. When you're pushing hard on the track or trail, you...09500014- SKU:
- 09500014
- Availability:
- Ships Same Business Day
- Weight:
- 0.13 LBS
- RIDING STYLE:
- OFF-ROAD
- COLOR/FINISH:
- ALUMINUM
- UNITS:
- EACH
- MATERIAL:
- 6061 ALUMINUM
- BASE COLOR:
- SILVER
- PRODUCT NAME:
- CASE SAVER
- TYPE:
- ENGINE
$23.95 -
MOOSE RACING Motor Gasket Kit with Seal - CR250 811257
MOOSE RACING
$77.38A complete engine and transmission rebuild demands precision-fit gaskets and seals that won't compromise your work or wallet. The MOOSE RACING Motor Gasket Kit delivers OEM-quality components at a fraction of dealership pricing, giving you the confidence...M811257- SKU:
- M811257
- Availability:
- Ships Same Business Day
- Weight:
- 0.31 LBS
- PRODUCT NAME:
- GASKET
- UNITS:
- KIT
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- COMPLETE
- THICKNESS IMPERIAL:
- 0,040'
- THICKNESS METRIC:
- 1.02 MM
- TYPE:
- ENGINE
$77.38 -
MOOSE RACING Engine Oil Seal Kit - Yamaha 822308
MOOSE RACING
$34.10Engine oil seals are critical wear items that prevent costly oil leakage and maintain proper lubrication throughout your engine. This MOOSE Racing complete seal kit eliminates the need to source individual seals from multiple suppliers, saving time and...09351022- SKU:
- 09351022
- Availability:
- Ships Same Business Day
- Weight:
- 0.06 LBS
- PRODUCT NAME:
- SEAL KIT
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- OIL
- UNITS:
- KIT
- APPLICATION:
- ENGINE
- RIDING STYLE:
- ADVENTURE TOURING / DUAL-SPORT
$34.10 -
MOOSE RACING Motor Gasket Kit with Seal - RM250 811580
MOOSE RACING
$88.44A complete engine and transmission rebuild demands precision-fit gaskets and seals that won't compromise your work or wallet. MOOSE Racing delivers OEM-quality components at a fraction of the cost, so you can rebuild with confidence knowing every...M811580- SKU:
- M811580
- Availability:
- Ships Same Business Day
- Weight:
- 0.25 LBS
- TYPE:
- ENGINE
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- COMPLETE
- PRODUCT NAME:
- GASKET
- UNITS:
- KIT
$88.44 -
MOOSE RACING Motor Gasket Kit with Seal - RM250 811583
MOOSE RACING
$114.69A complete engine and transmission rebuild demands precision-fit gaskets and seals—any compromise in quality leads to leaks, performance loss, and costly rework. This Moose Racing kit delivers OEM-specification components at a fraction of dealer pricing,...M811583- SKU:
- M811583
- Availability:
- Ships Same Business Day
- Weight:
- 0.25 LBS
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- COMPLETE
- PRODUCT NAME:
- GASKET
- TYPE:
- ENGINE
- UNITS:
- KIT
$114.69 -
MOOSE RACING Motor Gasket Kit with Seal - RM250 811587
MOOSE RACING
$112.56A complete engine and transmission rebuild demands precision gaskets and seals that won't compromise your work or your budget. MOOSE Racing delivers OEM-quality replacement seals at a fraction of dealership pricing, giving you the confidence to rebuild...M811587- SKU:
- M811587
- Availability:
- Ships Same Business Day
- Weight:
- 0.25 LBS
- PRODUCT NAME:
- GASKET
- UNITS:
- KIT
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- COMPLETE
- TYPE:
- ENGINE
$112.56 -
MOOSE RACING Inner Clutch Cover Gasket 816319
MOOSE RACING
$42.03A leaking clutch cover gasket compromises engine integrity and invites costly internal damage—this Moose Racing replacement stops seepage at the source. Factory-equivalent sealing performance at a fraction of OEM pricing means you get reliability without...09346153- SKU:
- 09346153
- Availability:
- Ships Same Business Day
- Weight:
- 0.12 LBS
- UNITS:
- EACH
- PRODUCT NAME:
- GASKET
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- CLUTCH COVER
$42.03 -
MOOSE RACING Ignition Cover Gasket 816510
MOOSE RACING
$7.09A compromised ignition cover gasket means oil seepage, potential engine damage, and unreliable performance when it matters most. The MOOSE RACING Ignition Cover Gasket 816510 delivers a factory-quality seal using premium materials engineered for the...09346154- SKU:
- 09346154
- Availability:
- Ships Same Business Day
- Weight:
- 0.11 LBS
- TYPE:
- IGNITION COVER
- RIDING STYLE:
- OFF-ROAD
- PRODUCT NAME:
- GASKET
- UNITS:
- EACH
$7.09 -
MOOSE RACING Ignition Cover Gasket 816517
MOOSE RACING
$5.29A quality ignition cover gasket is essential for maintaining a proper seal on your engine's ignition system, preventing oil leakage and contamination that can compromise ignition performance and reliability. MOOSE Racing's 816517 gasket is engineered to...09346155- SKU:
- 09346155
- Availability:
- Ships Same Business Day
- Weight:
- 0.11 LBS
- TYPE:
- IGNITION COVER
- PRODUCT NAME:
- GASKET
- UNITS:
- EACH
- RIDING STYLE:
- OFF-ROAD
$5.29 -
MOOSE RACING Ignition Cover Gasket 816532
MOOSE RACING
$10.02A worn or compromised ignition cover gasket can lead to oil seepage, contamination of ignition components, and potential electrical failures that sideline your engine. The MOOSE RACING Ignition Cover Gasket 816532 delivers a reliable OEM-quality seal...09346156- SKU:
- 09346156
- Availability:
- Ships Same Business Day
- Weight:
- 0.11 LBS
- TYPE:
- IGNITION COVER
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- EACH
- PRODUCT NAME:
- GASKET
$10.02 -
MOOSE RACING Motor Gasket Kit with Seal - Yamaha 811994
MOOSE RACING
$190.30A complete engine and transmission rebuild demands precision-fit gaskets and seals—using substandard components invites oil leaks, compression loss, and premature failure. The MOOSE RACING Motor Gasket Kit eliminates the guesswork and expense of sourcing...09345999- SKU:
- 09345999
- Availability:
- Ships Same Business Day
- Weight:
- 0.40 LBS
- ENGINE TYPE:
- 4-STROKE
- TYPE:
- COMPLETE
- TYPE:
- ENGINE
- PRODUCT NAME:
- GASKET
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
$190.30 -
MOOSE RACING Water Pump Rebuild Kit 821331
MOOSE RACING
$37.02A failing water pump doesn't just compromise cooling efficiency—it puts your entire engine at risk. This MOOSE RACING rebuild kit gives you a complete, factory-spec solution to restore your pump to OEM performance without the cost of replacement. Whether...09346000- SKU:
- 09346000
- Availability:
- Ships Same Business Day
- Weight:
- 0.16 LBS
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- PRODUCT NAME:
- REPAIR KIT
- TYPE:
- WATER PUMP
$37.02 -
MOOSE RACING Clutch Cover Gasket 819047
MOOSE RACING
$13.64A failing clutch cover gasket compromises engine sealing and invites oil leakage that degrades performance and reliability. The MOOSE RACING 819047 delivers OEM-quality sealing with precision engineering and domestic manufacturing, giving you the...09345902- SKU:
- 09345902
- Availability:
- Ships Same Business Day
- Weight:
- 0.10 LBS
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- CLUTCH COVER
- PRODUCT NAME:
- GASKET
- UNITS:
- EACH
$13.64 -
MOOSE RACING Head Cover Gasket - KTM 819048
MOOSE RACING
$13.64Head cover gaskets are critical sealing components that prevent oil leakage and maintain engine integrity during operation. OEM replacements come at a premium price, but the MOOSE RACING Head Cover Gasket delivers genuine reliability at a fraction of the...09345903- SKU:
- 09345903
- Availability:
- Ships Same Business Day
- Weight:
- 0.15 LBS
- RIDING STYLE:
- STREET
- ENGINE TYPE:
- 4-STROKE
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- HEAD COVER
- UNITS:
- EACH
- MATERIAL:
- RUBBER
- PRODUCT NAME:
- GASKET
$13.64 -
MOOSE RACING Complete Motor Gasket Kit - YZ125 808636
MOOSE RACING
$54.00A complete engine and transmission rebuild demands gaskets and seals engineered for precision fit and lasting durability. This Moose Racing kit eliminates the guesswork of sourcing individual components, giving you every gasket, o-ring, and seal needed...M808636- SKU:
- M808636
- Availability:
- Ships Same Business Day
- Weight:
- 0.10 LBS
- PRODUCT NAME:
- GASKET
- UNITS:
- KIT
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- COMPLETE
- TYPE:
- ENGINE
$54.00 -
MOOSE RACING Complete Motor Gasket Kit - YZ125 808637
MOOSE RACING
$53.66A complete engine and transmission rebuild demands gaskets and seals that match OEM precision without the OEM price tag. The MOOSE RACING Complete Motor Gasket Kit gives you every gasket, o-ring, and valve seal needed for a full bottom-end refresh, so...M808637- SKU:
- M808637
- Availability:
- Ships Same Business Day
- Weight:
- 0.15 LBS
- PRODUCT NAME:
- GASKET
- UNITS:
- KIT
- TYPE:
- ENGINE
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- COMPLETE
$53.66 -
MOOSE RACING Complete Motor Gasket Kit - YZ125 808639
MOOSE RACING
$53.66A complete engine and transmission rebuild demands precision gaskets and seals that won't compromise your work—this Moose Racing kit delivers OEM-quality components at a fraction of the cost. Whether you're refreshing your YZ125 after a season of hard...M808639- SKU:
- M808639
- Availability:
- Ships Same Business Day
- Weight:
- 0.15 LBS
- TYPE:
- ENGINE
- PRODUCT NAME:
- GASKET
- UNITS:
- KIT
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- COMPLETE
$53.66
