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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Cylinder Works Honda CRF 250R 2010-2017 Big Bore Cylinder Kit 270cc 11007-K01
CYLINDER WORKS
$758.95Stock displacement limits your Honda CRF 250R's potential—this big bore kit unlocks an additional 20cc of swept volume, delivering measurable gains in mid-range torque and top-end power without sacrificing reliability. The bolt-on design means you're...09310340- SKU:
- 09310340
- Availability:
- Ships Same Business Day
- Weight:
- 3.68 LBS
- COMPRESSION RATIO IMPERIAL:
- 13.2:1
- CYLINDER DIAMETER METRIC:
- 80.00 MM
- RIDING STYLE:
- OFF-ROAD
- DISPLACEMENT:
- 270 CC
- CYLINDER BORE COATING:
- NICKEL-SILICON CARBIDE
- CYLINDER DIAMETER:
- 80,00 MM
- PRODUCT NAME:
- CYLINDER KIT
- STYLE:
- BIG BORE
- UNITS:
- KIT
- ENGINE TYPE:
- 4-CYCLE
- OVERBORE METRIC:
- +3.20 MM
$758.95Qty in Cart: 0Quantity:Price:$758.95Subtotal: -
Cylinder Works Standard Bore Cylinder Kit Honda CRF250R 2010-2013 10007-K01
CYLINDER WORKS
$597.95When you're pushing a CRF250R to its limits, factory tolerances become a ceiling, not a target. The Cylinder Works Standard Bore Kit delivers a bolt-on refresh that restores compression, improves ring seal, and eliminates the guesswork of sourcing...09310338- SKU:
- 09310338
- Availability:
- Ships Same Business Day
- Weight:
- 3.55 LBS
- DISPLACEMENT:
- 249 CC
- ENGINE TYPE:
- 4-CYCLE
- PRODUCT NAME:
- CYLINDER KIT
- CYLINDER BORE COATING:
- NICKEL-SILICON CARBIDE
- CYLINDER DIAMETER:
- 76,80 MM
- UNITS:
- KIT
- CYLINDER DIAMETER METRIC:
- 76.80 MM
- RIDING STYLE:
- OFF-ROAD
- STYLE:
- STANDARD
- COMPRESSION RATIO IMPERIAL:
- 13.2:1
$597.95 -
On Sale
ATHENA Cylinder Kit - KX250F P400250100013
ATHENA
MSRP: $1,105.30Now: $995.00Was: $1,105.30A worn or damaged cylinder directly compromises your KX250F's power delivery, throttle response, and overall reliability on the track. The ATHENA Cylinder Kit restores factory performance while delivering improved durability through advanced materials...09310308- SKU:
- 09310308
- Availability:
- Ships Same Business Day
- Weight:
- 3.03 LBS
- BORE SIZE METRIC:
- 83.00 MM
- DISPLACEMENT:
- 290 CC
- ENGINE TYPE:
- 4-STROKE
- RIDING STYLE:
- OFF-ROAD
- CYLINDER BORE COATING:
- NICKEL-CARBIDE
- MATERIAL:
- ALUMINUM
- PRODUCT NAME:
- CYLINDER KIT
- STYLE:
- BIG BORE
- UNITS:
- KIT
MSRP: $1,105.30Now: $995.00Was: $1,105.30 -
Cylinder Works Standard Bore Cylinder Kit for 2002-2008 Honda CRF450R 10002-K01
CYLINDER WORKS
$651.95The Honda CRF450R demands reliable power delivery, especially if you're logging serious hours at the track or trail. This Cylinder Works kit delivers a complete bolt-on solution with matched Vertex pistons, eliminating guesswork and machine work while...09310272- SKU:
- 09310272
- Availability:
- Ships Same Business Day
- Weight:
- 4.51 LBS
- CYLINDER BORE COATING:
- NICKEL-SILICON CARBIDE
- CYLINDER DIAMETER:
- 96,00 MM
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- COMPRESSION RATIO IMPERIAL:
- 12.1:1
- DISPLACEMENT:
- 449 CC
- ENGINE TYPE:
- 4-CYCLE
- PRODUCT NAME:
- CYLINDER KIT
- CYLINDER DIAMETER METRIC:
- 96.00 MM
- STYLE:
- STANDARD
$651.95 -
Cylinder Works Standard Bore Cylinder Kit Honda CRF250R 2008-2009 10001-K02
CYLINDER WORKS
$609.95The Honda CRF250R demands reliable power delivery, and a worn cylinder limits both performance and engine longevity. This Cylinder Works Standard Bore Kit restores your engine to peak efficiency with factory-quality components and Vertex pistons...09310271- SKU:
- 09310271
- Availability:
- Ships Same Business Day
- Weight:
- 3.55 LBS
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- STYLE:
- STANDARD
- COMPRESSION RATIO IMPERIAL:
- 13.0:1
- CYLINDER DIAMETER:
- 78,00 MM
- DISPLACEMENT:
- 249 CC
- ENGINE TYPE:
- 4-CYCLE
- PRODUCT NAME:
- CYLINDER KIT
- CYLINDER BORE COATING:
- NICKEL-SILICON CARBIDE
- CYLINDER DIAMETER METRIC:
- 78.00 MM
$609.95 -
Cylinder Works Standard Bore Cylinder Kit Honda CRF450R 2017-2018 10001-K01
CYLINDER WORKS
$597.95Stock cylinder wear limits your CRF450R's potential, whether you're chasing track times or extending engine life on your rebuild. The Cylinder Works Standard Bore Kit delivers a direct bolt-on solution with matched components—no machine work, no...09310270- SKU:
- 09310270
- Availability:
- Ships Same Business Day
- Weight:
- 4.32 LBS
- COMPRESSION RATIO IMPERIAL:
- 12.9:1
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- CYLINDER BORE COATING:
- NICKEL-SILICON CARBIDE
- CYLINDER DIAMETER METRIC:
- 78.00 MM
- CYLINDER DIAMETER:
- 78,00 MM
- DISPLACEMENT:
- 249 CC
- ENGINE TYPE:
- 4-CYCLE
- PRODUCT NAME:
- CYLINDER KIT
- STYLE:
- STANDARD
$597.95 -
Cylinder Works Cylinder Kit Standard 66mm Bore 11.7:1 Compression Honda CRF150R 2007-2009 10004-K01
CYLINDER WORKS
$550.95If you're running a CRF150R and want measurable power gains without the downtime of traditional re-plating, this complete cylinder kit delivers bolt-on simplicity and proven durability. The matched Vertex piston pairing reduces noise and extends ring...09310269- SKU:
- 09310269
- Availability:
- Ships Same Business Day
- Weight:
- 2.80 LBS
- CYLINDER BORE COATING:
- NICKEL-SILICON CARBIDE
- CYLINDER DIAMETER METRIC:
- 66.00 MM
- STYLE:
- STANDARD
- CYLINDER DIAMETER:
- 66,00 MM
- DISPLACEMENT:
- 149 CC
- ENGINE TYPE:
- 4-CYCLE
- COMPRESSION RATIO IMPERIAL:
- 11.7:1
- PRODUCT NAME:
- CYLINDER KIT
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
$550.95 -
On Sale
ATHENA Cylinder Kit - YZ125 - 58mm P400485100029
ATHENA
MSRP: $1,223.95Now: $1,102.00Was: $1,223.95The ATHENA Cylinder Kit for YZ125 delivers measurable performance gains through precision engineering and superior materials. If you're running stock components, you're leaving horsepower on the table—this kit's larger water jackets and advanced coatings...09310258- SKU:
- 09310258
- Availability:
- Ships Same Business Day
- Weight:
- 5.43 LBS
- BORE SIZE METRIC:
- 58.00 MM
- MATERIAL:
- ALUMINUM
- CYLINDER BORE COATING:
- NICKEL-CARBIDE
- ENGINE TYPE:
- 2-STROKE
- DISPLACEMENT:
- 144 CC
- PRODUCT NAME:
- CYLINDER KIT
- RIDING STYLE:
- OFF-ROAD
- STYLE:
- BIG BORE
- UNITS:
- KIT
MSRP: $1,223.95Now: $1,102.00Was: $1,223.95 -
On Sale
ATHENA Cylinder Kit - WR250R/X - 83mm P400485100032
ATHENA
MSRP: $1,352.95Now: $1,218.00Was: $1,352.95If you're running a WR250R/X and want to unlock genuine displacement gains with measurable power increases, the ATHENA Cylinder Kit delivers the reliability and precision engineering that separates bolted performance from half-measures. This 83mm...09310252- SKU:
- 09310252
- Availability:
- Ships Same Business Day
- Weight:
- 4.29 LBS
- PRODUCT NAME:
- CYLINDER KIT
- STYLE:
- BIG BORE
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- BORE SIZE METRIC:
- 83.00 MM
- CYLINDER BORE COATING:
- NICKEL-CARBIDE
- DISPLACEMENT:
- 290 CC
- ENGINE TYPE:
- 4-STROKE
- MATERIAL:
- ALUMINUM
MSRP: $1,352.95Now: $1,218.00Was: $1,352.95 -
On Sale
ATHENA Cylinder Kit - SX65 - 50mm P400270100002
ATHENA
MSRP: $872.95Now: $786.00Was: $872.95The ATHENA Cylinder Kit for SX65 delivers the displacement and thermal management your 50mm bore demands. With a nickel-carbide coated aluminum cylinder and forged piston engineered for durability, this kit handles aggressive riding without compromise...09310245- SKU:
- 09310245
- Availability:
- Ships Same Business Day
- Weight:
- 3.28 LBS
- DISPLACEMENT:
- 80 CC
- MATERIAL:
- ALUMINUM
- BORE SIZE METRIC:
- 50.00 MM
- CYLINDER BORE COATING:
- NICKEL-CARBIDE
- ENGINE TYPE:
- 2-STROKE
- PRODUCT NAME:
- CYLINDER KIT
- RIDING STYLE:
- OFF-ROAD
- STYLE:
- BIG BORE
- UNITS:
- KIT
MSRP: $872.95Now: $786.00Was: $872.95 -
Cylinder Works Big Bore Kit Yamaha YZ450F 2006-2009 WR450F 2007-2015 21003-K01
CYLINDER WORKS
$873.95If you're running a YZ450F or WR450F and want measurable gains in displacement and power output, a big bore kit is the most efficient path forward. The Cylinder Works Big Bore Kit delivers bolt-on simplicity without sacrificing the reliability and fit of...09310174- SKU:
- 09310174
- Availability:
- Ships Same Business Day
- Weight:
- 4.04 LBS
- ENGINE TYPE:
- 4-CYCLE
- PRODUCT NAME:
- CYLINDER KIT
- STYLE:
- BIG BORE
- DISPLACEMENT:
- 478 CC
- COMPRESSION RATIO IMPERIAL:
- 12.5:1
- CYLINDER BORE COATING:
- NICKEL-SILICON CARBIDE
- CYLINDER DIAMETER:
- 98,00 MM
- CYLINDER DIAMETER METRIC:
- 98.00 MM
- OVERBORE METRIC:
- +3.00 MM
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
$873.95Qty in Cart: 0Quantity:Price:$873.95Subtotal: -
Cylinder Works Big Bore Cylinder Kit for Honda CRF250R 2004-2009 2012-2013 CRF250X 2004-2017 11001-K01
CYLINDER WORKS
$752.95If you're running a CRF250R or CRF250X and want measurable gains in displacement and power without a complete engine overhaul, the Cylinder Works Big Bore Kit delivers exactly that. This bolt-on upgrade eliminates the guesswork with a matched...09310118- SKU:
- 09310118
- Availability:
- Ships Same Business Day
- Weight:
- 3.03 LBS
- CYLINDER DIAMETER METRIC:
- 81.00 MM
- RIDING STYLE:
- OFF-ROAD
- ENGINE TYPE:
- 4-CYCLE
- COMPRESSION RATIO IMPERIAL:
- 13.0:1
- CYLINDER DIAMETER:
- 81,00 MM
- CYLINDER BORE COATING:
- NICKEL-SILICON CARBIDE
- DISPLACEMENT:
- 269 CC
- OVERBORE METRIC:
- +3.00 MM
- PRODUCT NAME:
- CYLINDER KIT
- STYLE:
- BIG BORE
- UNITS:
- KIT
$752.95 -
On Sale
ATHENA Cylinder Kit - RMZ450 - 100mm P400510100006
ATHENA
MSRP: $1,156.95Now: $1,041.00Was: $1,156.95The ATHENA Cylinder Kit delivers measurable gains in displacement and compression for the RMZ450, translating directly to increased horsepower and throttle response. The nickel-carbide coated aluminum cylinder and molybdenum-coated forged piston are...09310114- SKU:
- 09310114
- Availability:
- Ships Same Business Day
- Weight:
- 3.73 LBS
- PRODUCT NAME:
- CYLINDER KIT
- STYLE:
- BIG BORE
- DISPLACEMENT:
- 490 CC
- ENGINE TYPE:
- 4-STROKE
- MATERIAL:
- ALUMINUM
- CYLINDER BORE COATING:
- NICKEL-CARBIDE
- UNITS:
- KIT
- BORE SIZE METRIC:
- 100.00 MM
- RIDING STYLE:
- OFF-ROAD
MSRP: $1,156.95Now: $1,041.00Was: $1,156.95 -
On Sale
ATHENA Cylinder Kit - KX125 - 58mm P400250100011
ATHENA
MSRP: $1,201.95Now: $1,082.00Was: $1,201.95The ATHENA Cylinder Kit delivers the displacement and reliability your KX125 demands when stock limits won't cut it. With a 58mm bore, optimized water jacket design, and factory-grade coatings, you're getting race-proven engineering that bolts straight...09310109- SKU:
- 09310109
- Availability:
- Ships Same Business Day
- Weight:
- 5.62 LBS
- BORE SIZE METRIC:
- 58.00 MM
- MATERIAL:
- ALUMINUM
- CYLINDER BORE COATING:
- NICKEL-CARBIDE
- ENGINE TYPE:
- 2-STROKE
- RIDING STYLE:
- OFF-ROAD
- DISPLACEMENT:
- 144 CC
- PRODUCT NAME:
- CYLINDER KIT
- STYLE:
- BIG BORE
- UNITS:
- KIT
MSRP: $1,201.95Now: $1,082.00Was: $1,201.95 -
On Sale
ATHENA Cylinder Kit - KX65 - 50mm P400250100007
ATHENA
MSRP: $932.95Now: $840.00Was: $932.95If you're pushing your KX65 to its limits, a worn or compromised cylinder is a bottleneck you can't afford. The ATHENA Cylinder Kit delivers measurable gains in compression consistency and heat dissipation, translating directly to more responsive...09310107- SKU:
- 09310107
- Availability:
- Ships Same Business Day
- Weight:
- 3.31 LBS
- PRODUCT NAME:
- CYLINDER KIT
- STYLE:
- BIG BORE
- DISPLACEMENT:
- 80 CC
- BORE SIZE METRIC:
- 50.00 MM
- CYLINDER BORE COATING:
- NICKEL-CARBIDE
- ENGINE TYPE:
- 2-STROKE
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- MATERIAL:
- ALUMINUM
MSRP: $932.95Now: $840.00Was: $932.95 -
On Sale
ATHENA Cylinder Kit - YZ125 - 54mm P400485100017
ATHENA
MSRP: $1,110.95Now: $1,000.00Was: $1,110.95The ATHENA Cylinder Kit delivers the displacement and reliability your YZ125 needs to stay competitive on the track. With a larger 54mm bore and premium coatings engineered for durability, this kit provides measurable power gains while maintaining the...09310095- SKU:
- 09310095
- Availability:
- Ships Same Business Day
- Weight:
- 5.61 LBS
- DISPLACEMENT:
- 125 CC
- PRODUCT NAME:
- CYLINDER KIT
- MATERIAL:
- ALUMINUM
- BORE SIZE METRIC:
- 54.00 MM
- CYLINDER BORE COATING:
- NICKEL-CARBIDE
- ENGINE TYPE:
- 2-STROKE
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- STYLE:
- STOCK BORE
MSRP: $1,110.95Now: $1,000.00Was: $1,110.95 -
On Sale
ATHENA Cylinder Kit - Yamaha 070200
ATHENA
MSRP: $262.95Now: $237.00Was: $262.95Restore your Yamaha's peak performance with a complete cylinder kit engineered for reliability and longevity. The ATHENA 070200 combines a reinforced aluminum cylinder with advanced thermal management and a forged piston designed to handle sustained...09310077- SKU:
- 09310077
- Availability:
- Ships Same Business Day
- Weight:
- 2.70 LBS
- CYLINDER BORE COATING:
- NICKEL-CARBIDE
- ENGINE TYPE:
- 2-STROKE
- UNITS:
- KIT
- DISPLACEMENT:
- 70 CC
- PRODUCT NAME:
- CYLINDER KIT
- RIDING STYLE:
- STREET
- STYLE:
- BIG BORE
- BORE SIZE METRIC:
- 47.66 MM
- MATERIAL:
- ALUMINUM
MSRP: $262.95Now: $237.00Was: $262.95 -
On Sale
ATHENA Cylinder Kit - Yamaha/Malaguti 070100
ATHENA
MSRP: $262.95Now: $237.00Was: $262.95When you're ready to unlock serious performance gains on your Yamaha or Malaguti 070, a quality cylinder kit is non-negotiable. The ATHENA Cylinder Kit delivers the displacement and durability you need to maximize horsepower and torque without...09310076- SKU:
- 09310076
- Availability:
- Ships Same Business Day
- Weight:
- 2.80 LBS
- CYLINDER BORE COATING:
- NICKEL-CARBIDE
- UNITS:
- KIT
- DISPLACEMENT:
- 70 CC
- PRODUCT NAME:
- CYLINDER KIT
- RIDING STYLE:
- STREET
- STYLE:
- BIG BORE
- BORE SIZE METRIC:
- 47.66 MM
- ENGINE TYPE:
- 2-STROKE
- MATERIAL:
- ALUMINUM
MSRP: $262.95Now: $237.00Was: $262.95 -
On Sale
ATHENA Cylinder Kit - KLX/DRZ/KFX/LTZ400 P400510100002
ATHENA
MSRP: $1,117.95Now: $1,006.00Was: $1,117.95Stock cylinder limitations can compromise peak horsepower and throttle response on your KLX, DRZ, KFX, or LTZ400. The ATHENA Cylinder Kit delivers measurable gains through advanced materials and thermal engineering—larger water jackets keep temperatures...09310016- SKU:
- 09310016
- Availability:
- Ships Same Business Day
- Weight:
- 4.96 LBS
- DISPLACEMENT:
- 435 CC
- MATERIAL:
- ALUMINUM
- BORE SIZE METRIC:
- 94.00 MM
- ENGINE TYPE:
- 4-STROKE
- RIDING STYLE:
- ATV
- RIDING STYLE:
- OFF-ROAD
- CYLINDER BORE COATING:
- NICKEL-CARBIDE
- RIDING STYLE:
- STREET
- PRODUCT NAME:
- CYLINDER KIT
- STYLE:
- BIG BORE
- UNITS:
- KIT
MSRP: $1,117.95Now: $1,006.00Was: $1,117.95 -
On Sale
ATHENA Cylinder Kit - DRZ/KFX P400510100001
ATHENA
MSRP: $772.95Now: $696.00Was: $772.95Stock cylinder limits your engine's potential, especially if you're running higher compression or extended operating hours. The ATHENA Cylinder Kit delivers measurable gains in peak power and reliability through precision engineering and materials...09310015- SKU:
- 09310015
- Availability:
- Ships Same Business Day
- Weight:
- 4.71 LBS
- BORE SIZE METRIC:
- 90.00 MM
- MATERIAL:
- ALUMINUM
- STYLE:
- STOCK BORE
- CYLINDER BORE COATING:
- NICKEL-CARBIDE
- ENGINE TYPE:
- 4-STROKE
- RIDING STYLE:
- ATV
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- PRODUCT NAME:
- CYLINDER KIT
- DISPLACEMENT:
- 400 CC
MSRP: $772.95Now: $696.00Was: $772.95
