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
-
LA Sleeve Sleeve and Piston Kit Kawasaki KX85 2014-2019 LAS5778K
LA SLEEVE
$326.95When your Kawasaki KX85 starts losing compression and power, a worn top-end compromises both reliability and lap times. The LA Sleeve Sleeve and Piston Kit restores your engine to peak efficiency with a centrifugally spun-cast iron bore that delivers...09310861- SKU:
- 09310861
- Availability:
- Ships Same Business Day
- Weight:
- 1.65 LBS
- PRODUCT NAME:
- SLEEVE AND PISTON KIT
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
$326.95 -
K&S TECHNOLOGIES Water Pump Repair Kit - CR85R 75-1008
K&S TECHNOLOGIES
$32.95A leaking water pump doesn't just waste coolant—it compromises engine temperature stability and can lead to catastrophic overheating on the track or trail. The K&S Technologies Water Pump Repair Kit supplies all gaskets, seals, and O-rings needed to...09342879- SKU:
- 09342879
- Availability:
- Ships Same Business Day
- Weight:
- 0.26 LBS
- PRODUCT NAME:
- GASKET KIT
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- WATER PUMP REPAIR
- UNITS:
- KIT
$32.95Qty in Cart: 0Quantity:Price:$32.95Subtotal: -
CYCLE CRAFT Friction Washer 39-21252
CYCLE CRAFT
$37.23Kits contain main spring, cover plate, throw-out springs, pawls, D-washers, rope and pull handle, Parts fit all models ATC185/200; will also fit 90/110 models if different rope is used, Fit models ATC185 80, ATC185S 81-83, ATC200 81-83, ATC200E Big Red...21252- SKU:
- 21252
- Availability:
- Ships Same Business Day
- Weight:
- 0.10 LBS
- PRODUCT NAME:
- WASHER
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- EACH
- TYPE:
- STARTER
$37.23 -
CYCLE CRAFT Friction Plate 39-21253
CYCLE CRAFT
$14.31Kits contain main spring, cover plate, throw-out springs, pawls, D-washers, rope and pull handle, Parts fit all models ATC185/200; will also fit 90/110 models if different rope is used, Fit models ATC185 80, ATC185S 81-83, ATC200 81-83, ATC200E Big Red...21253- SKU:
- 21253
- Availability:
- Ships Same Business Day
- Weight:
- 0.13 LBS
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- EACH
- PRODUCT NAME:
- COVER PLATE
- TYPE:
- STARTER
$14.31 -
Cylinder Works Standard Bore Cylinder KTM 50 SX 2009-2023 CW50012
CYLINDER WORKS
$434.95When your KTM 50 SX's cylinder shows signs of wear—scored walls, compression loss, or damaged plating—a quality replacement is essential to restore engine integrity and performance. The Cylinder Works Standard Bore cylinder delivers OEM-equivalent...09311022- SKU:
- 09311022
- Availability:
- Ships Same Business Day
- Weight:
- 2.61 LBS
- UNITS:
- EACH
- CYLINDER DIAMETER METRIC:
- 39.50 MM
- PRODUCT NAME:
- CYLINDER
- RIDING STYLE:
- OFF-ROAD
- CYLINDER DIAMETER:
- 39,50 MM
- ENGINE TYPE:
- 2-CYCLE
- STYLE:
- STANDARD
$434.95 -
Cylinder Works Standard Bore Cylinder for Polaris RZR 900 2017-2020 CW60007
CYLINDER WORKS
$696.95When your Polaris RZR 900 cylinder shows wear or you're rebuilding after hard use, OEM replacement costs and lead times can sideline your rig. The Cylinder Works Standard Bore CW60007 delivers a direct bolt-on solution without the expense and hassle of...09311023- SKU:
- 09311023
- Availability:
- Ships Same Business Day
- Weight:
- 7.16 LBS
- UNITS:
- EACH
- CYLINDER DIAMETER METRIC:
- 93.00 MM
- ENGINE TYPE:
- 4-CYCLE
- RIDING STYLE:
- UTV
- STYLE:
- STANDARD
- CYLINDER DIAMETER:
- 93,00 MM
- PRODUCT NAME:
- CYLINDER
$696.95Qty in Cart: 0Quantity:Price:$696.95Subtotal: -
Cylinder Works Yamaha WR250F 2018-2019 High Compression Cylinder Kit 20010-K02HC
CYLINDER WORKS
$750.95If you're running a WR250F, factory displacement limits your peak performance and torque delivery. The Cylinder Works high-compression big bore kit unlocks additional cubic centimeters and compression ratio, delivering measurable power gains while...09310709- SKU:
- 09310709
- Availability:
- Ships Same Business Day
- Weight:
- 3.20 LBS
- CYLINDER DIAMETER METRIC:
- 77.00 MM
- CYLINDER DIAMETER:
- 77,00 MM
- PRODUCT NAME:
- CYLINDER KIT
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- BORE SIZE METRIC:
- 77.00 MM
- COMPRESSION RATIO IMPERIAL:
- 14.2:1
- STYLE:
- STANDARD
- ENGINE TYPE:
- 4-CYCLE
$750.95 -
Cylinder Works Standard Bore Cylinder Kit for 2007-2008 Honda CRF450R 10002-K02
CYLINDER WORKS
$651.95Stock CRF450R cylinders wear, lose compression, and rob you of the power you've built. The Cylinder Works Standard Bore Kit restores your engine to original specifications while delivering the durability and reliability you need for consistent track...09310839- SKU:
- 09310839
- Availability:
- Ships Same Business Day
- Weight:
- 4.71 LBS
- CYLINDER BORE COATING:
- NICKEL-SILICON CARBIDE
- CYLINDER DIAMETER:
- 96,00 MM
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- CYLINDER DIAMETER METRIC:
- 96.00 MM
- OVERBORE METRIC:
- STANDARD
- STYLE:
- STANDARD
- DISPLACEMENT:
- 449 CC
- ENGINE TYPE:
- 4-CYCLE
- PRODUCT NAME:
- CYLINDER KIT
- COMPRESSION RATIO IMPERIAL:
- 12.1:1
$651.95 -
Cylinder Works Big Bore Cylinder Kit for Honda CRF450R 2007-2019 10002-K02HC
CYLINDER WORKS
$690.95If you're running a Honda CRF450R, factory displacement limits your peak power output when you're pushing hard on the track or trail. The Cylinder Works Big Bore Kit removes that constraint with a straightforward bolt-on upgrade that delivers measurable...09310841- SKU:
- 09310841
- Availability:
- Ships Same Business Day
- Weight:
- 4.71 LBS
- CYLINDER BORE COATING:
- NICKEL-SILICON CARBIDE
- CYLINDER DIAMETER:
- 96,00 MM
- UNITS:
- KIT
- COMPRESSION RATIO IMPERIAL:
- 12.5:1
- DISPLACEMENT:
- 449 CC
- ENGINE TYPE:
- 4-CYCLE
- PRODUCT NAME:
- CYLINDER KIT
- STYLE:
- BIG BORE
- CYLINDER DIAMETER METRIC:
- 96.00 MM
- RIDING STYLE:
- OFF-ROAD
$690.95 -
Cylinder Works Standard Bore Cylinder Kit Arctic Cat 400 DVX 2004-2008 40001-K02
CYLINDER WORKS
$717.95If your Arctic Cat 400 DVX is experiencing bore wear or you're looking to restore factory performance, the Cylinder Works Standard Bore Cylinder Kit delivers a complete, bolt-on solution without the downtime of machine work or re-plating. This matched...09310842- SKU:
- 09310842
- Availability:
- Ships Same Business Day
- Weight:
- 5.16 LBS
- CYLINDER BORE COATING:
- NICKEL-SILICON CARBIDE
- STYLE:
- STANDARD
- CYLINDER DIAMETER:
- 90,00 MM
- PRODUCT NAME:
- CYLINDER KIT
- UNITS:
- KIT
- COMPRESSION RATIO IMPERIAL:
- 11.3:1
- DISPLACEMENT:
- 400 CC
- CYLINDER DIAMETER METRIC:
- 90.00 MM
- ENGINE TYPE:
- 4-CYCLE
- RIDING STYLE:
- ATV
$717.95 -
Cylinder Works Standard Bore High Compression Cylinder Kit for 2004-2008 Arctic Cat 400 DVX 40001-K02HC
CYLINDER WORKS
$716.95If you're running a 2004-2008 Arctic Cat 400 DVX and want measurable gains in displacement and compression ratio without extensive machine work, this Cylinder Works kit delivers a bolt-on solution. The matched Vertex pistons and Nickel Silicon Carbide...09310843- SKU:
- 09310843
- Availability:
- Ships Same Business Day
- Weight:
- 5.16 LBS
- DISPLACEMENT:
- 400 CC
- ENGINE TYPE:
- 4-CYCLE
- CYLINDER DIAMETER METRIC:
- 90.00 MM
- RIDING STYLE:
- ATV
- COMPRESSION RATIO IMPERIAL:
- 13.5:1
- CYLINDER BORE COATING:
- NICKEL-SILICON CARBIDE
- CYLINDER DIAMETER:
- 90,00 MM
- PRODUCT NAME:
- CYLINDER KIT
- STYLE:
- BIG BORE
- UNITS:
- KIT
$716.95 -
Cylinder Works Standard Bore Cylinder Kit for 2018-2019 Honda CRF250R CW10011K01
CYLINDER WORKS
$622.95If you're running a 2018-2019 CRF250R, this cylinder kit delivers a direct path to increased displacement and responsive power without the downtime of custom machine work. The matched Vertex piston and Nickel Silicon Carbide plating work together to...09310845- SKU:
- 09310845
- Availability:
- Ships Same Business Day
- Weight:
- 3.46 LBS
- DISPLACEMENT:
- 249 CC
- ENGINE TYPE:
- 4-CYCLE
- CYLINDER DIAMETER:
- 79,00 MM
- STYLE:
- STANDARD
- COMPRESSION RATIO IMPERIAL:
- 13.9:1
- CYLINDER DIAMETER METRIC:
- 79.00 MM
- RIDING STYLE:
- OFF-ROAD
- CYLINDER BORE COATING:
- NICKEL-SILICON CARBIDE
- PRODUCT NAME:
- CYLINDER KIT
- UNITS:
- KIT
$622.95 -
Cylinder Works High Compression Cylinder Kit Honda CRF250R 2018-2019 CW10011K01HC
CYLINDER WORKS
$664.95The CRF250R demands more power to stay competitive on the track or trail, and the Cylinder Works High Compression Cylinder Kit delivers exactly that without requiring expensive machine work or downtime. This bolt-on big bore kit increases displacement...09310846- SKU:
- 09310846
- Availability:
- Ships Same Business Day
- Weight:
- 3.41 LBS
- DISPLACEMENT:
- 249 CC
- ENGINE TYPE:
- 4-CYCLE
- PRODUCT NAME:
- CYLINDER KIT
- CYLINDER BORE COATING:
- NICKEL-SILICON CARBIDE
- STYLE:
- BIG BORE
- CYLINDER DIAMETER METRIC:
- 79.00 MM
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- COMPRESSION RATIO IMPERIAL:
- 14.6:1
- CYLINDER DIAMETER:
- 79,00 MM
$664.95 -
Cylinder Works Big Bore Cylinder Kit Honda CRF250R 2018-2021 CRF250RX 2019-2021 CW11011K01
CYLINDER WORKS
$787.95Stock Honda CRF250R and CRF250RX cylinders limit your engine's potential and wear faster under aggressive riding conditions. This Cylinder Works big bore kit adds displacement and durability without requiring machine work or re-plating—just bolt it on...09310847- SKU:
- 09310847
- Availability:
- Ships Same Business Day
- Weight:
- 3.16 LBS
- ENGINE TYPE:
- 4-CYCLE
- PRODUCT NAME:
- CYLINDER KIT
- STYLE:
- BIG BORE
- DISPLACEMENT:
- 270 CC
- CYLINDER BORE COATING:
- NICKEL-SILICON CARBIDE
- CYLINDER DIAMETER:
- 82,00 MM
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- COMPRESSION RATIO IMPERIAL:
- 13.9:1
- CYLINDER DIAMETER METRIC:
- 82.00 MM
$787.95 -
Cylinder Works Standard Bore Cylinder Yamaha YZ450F 2018-2019 CW20012
CYLINDER WORKS
$461.95Stock cylinders wear down over time, reducing compression, power delivery, and overall engine reliability—especially under racing or high-performance conditions. The Cylinder Works Standard Bore Cylinder gives you a factory-spec replacement with superior...09310848- SKU:
- 09310848
- Availability:
- Ships Same Business Day
- Weight:
- 3.31 LBS
- PRODUCT NAME:
- CYLINDER
- ENGINE TYPE:
- 4-STROKE
- UNITS:
- EACH
- CYLINDER BORE COATING:
- NICKEL-SILICON CARBIDE
- RIDING STYLE:
- OFF-ROAD
- STYLE:
- STANDARD
$461.95 -
Cylinder Works Standard Bore Cylinder Kit Yamaha YZ450F 2018-2019 CW20012K01
CYLINDER WORKS
$788.95Worn cylinder walls and piston wear rob your YZ450F of compression, throttle response, and reliability. The Cylinder Works Standard Bore Kit restores your engine to factory specifications with matched components and precision machining—eliminating...09310849- SKU:
- 09310849
- Availability:
- Ships Same Business Day
- Weight:
- 4.56 LBS
- COMPRESSION RATIO IMPERIAL:
- 12.8:1
- CYLINDER DIAMETER:
- 97,00 MM
- DISPLACEMENT:
- 449 CC
- ENGINE TYPE:
- 4-CYCLE
- PRODUCT NAME:
- CYLINDER KIT
- RIDING STYLE:
- OFF-ROAD
- CYLINDER BORE COATING:
- NICKEL-SILICON CARBIDE
- CYLINDER DIAMETER METRIC:
- 97.00 MM
- STYLE:
- STANDARD
- UNITS:
- KIT
$788.95 -
Cylinder Works 2019-2020 Yamaha WR 450 F High Compression Big Bore Cylinder Kit CW20012K01HC
CYLINDER WORKS
$801.95If you're running a 2019-2020 WR 450F and want measurable power gains without extensive machine work, this big bore kit delivers real displacement increases that translate directly to torque and acceleration. The ready-to-install design means you're not...09310850- SKU:
- 09310850
- Availability:
- Ships Same Business Day
- Weight:
- 4.51 LBS
- COMPRESSION RATIO IMPERIAL:
- 13.8:1
- CYLINDER BORE COATING:
- NICKEL-SILICON CARBIDE
- DISPLACEMENT:
- 449 CC
- PRODUCT NAME:
- CYLINDER KIT
- RIDING STYLE:
- OFF-ROAD
- STYLE:
- BIG BORE
- UNITS:
- KIT
- CYLINDER DIAMETER:
- 97,00 MM
- CYLINDER DIAMETER METRIC:
- 97.00 MM
- ENGINE TYPE:
- 4-CYCLE
$801.95 -
Cylinder Works Standard Bore Cylinder Kit for Polaris RZR 900 2017-2020 CW60007K02
CYLINDER WORKS
$1,120.95Your Polaris RZR 900's factory cylinder is reliable, but a properly engineered replacement kit unlocks measurable gains in durability, consistency, and longevity. If you're running higher hours, increased boost pressure, or simply want a fresh,...09310852- SKU:
- 09310852
- Availability:
- Ships Same Business Day
- Weight:
- 10.11 LBS
- PRODUCT NAME:
- CYLINDER KIT
- CYLINDER DIAMETER:
- 93,00 MM
- DISPLACEMENT:
- 875 CC
- RIDING STYLE:
- UTV
- COMPRESSION RATIO IMPERIAL:
- 10.5:1
- CYLINDER BORE COATING:
- NICKEL-SILICON CARBIDE
- CYLINDER DIAMETER METRIC:
- 93.00 MM
- STYLE:
- STANDARD
- UNITS:
- KIT
- ENGINE TYPE:
- 4-CYCLE
$1,120.95 -
Cylinder Works High Compression Big Bore Cylinder Kit for Polaris RZR 900 2017-2020 CW60007K01HC
CYLINDER WORKS
$1,110.95If you're running a Polaris RZR 900 and want measurable gains in displacement and compression ratio without extensive machine work, the Cylinder Works High Compression Big Bore Kit delivers the displacement increase and reliability you need. This bolt-on...09310853- SKU:
- 09310853
- Availability:
- Ships Same Business Day
- Weight:
- 10.01 LBS
- CYLINDER BORE COATING:
- NICKEL-SILICON CARBIDE
- CYLINDER DIAMETER METRIC:
- 93.00 MM
- DISPLACEMENT:
- 875 CC
- UNITS:
- KIT
- CYLINDER DIAMETER:
- 93,00 MM
- RIDING STYLE:
- UTV
- COMPRESSION RATIO IMPERIAL:
- 11.5:1
- ENGINE TYPE:
- 4-CYCLE
- PRODUCT NAME:
- CYLINDER KIT
- STYLE:
- BIG BORE
$1,110.95 -
Cylinder Works Standard Bore Cylinder Kit 2016-2017 Honda CRF250R 10007-K03
CYLINDER WORKS
$609.95If your 2016-2017 Honda CRF250R is showing signs of wear on the cylinder or you're rebuilding after a top-end failure, a fresh cylinder kit restores compression and throttle response without the guesswork of sourcing individual components. The Cylinder...09310674- SKU:
- 09310674
- Availability:
- Ships Same Business Day
- Weight:
- 3.35 LBS
- COMPRESSION RATIO IMPERIAL:
- 13.5:1
- ENGINE TYPE:
- 4-CYCLE
- PRODUCT NAME:
- CYLINDER KIT
- BORE SIZE METRIC:
- 76.80 MM
- CYLINDER BORE COATING:
- NICKEL-SILICON CARBIDE
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- CYLINDER DIAMETER:
- 76,80 MM
- CYLINDER DIAMETER METRIC:
- 76.80 MM
- STYLE:
- STANDARD
$609.95
