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 Top End Gasket Kit - CR250R 810253
MOOSE RACING
$23.33A top-end rebuild demands precision and reliability—cutting corners on gaskets and seals will cost you on track or trail. This Moose Racing kit eliminates the guesswork by bundling every gasket, O-ring, and seal you need for a complete CR250R top-end...M810253- SKU:
- M810253
- Availability:
- Ships Same Business Day
- Weight:
- 0.13 LBS
- UNITS:
- KIT
- PRODUCT NAME:
- GASKET
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- TOP END
$23.33 -
LA Sleeve Cylinder Sleeve for Suzuki LT250R 1988-1992 FL5064
LA SLEEVE
$148.95When cylinder wear compromises compression and power delivery, a quality sleeve restoration becomes essential for reliable performance. The LA SLEEVE FL5064 restores your Suzuki LT250R's original bore dimensions, eliminating blow-by and revitalizing...FL5064- SKU:
- FL5064
- Availability:
- Ships Same Business Day
- Weight:
- 2.19 LBS
- BORE SIZE METRIC:
- 67.00 MM
- COLOR/FINISH:
- ALUMINUM
- PRODUCT NAME:
- CYLINDER SLEEVE
- TYPE:
- CS
- RIDING STYLE:
- ATV
- UNITS:
- EACH
- CYLINDER BORE COATING:
- CHROME-MOLY ALLOY
$148.95Qty in Cart: 0Quantity:Price:$148.95Subtotal: -
LA Sleeve Cylinder Sleeve 1989-1990 Suzuki RM250 RMX250 67mm Bore FL5093
LA SLEEVE
$153.95If you're rebuilding a 1989-1990 RM250 or RMX250, a worn cylinder is the bottleneck preventing peak performance. The LA SLEEVE FL5093 restores compression and sealing integrity, giving you the reliability needed for serious riding or racing. This...FL5093- SKU:
- FL5093
- Availability:
- Ships Same Business Day
- Weight:
- 1.31 LBS
- COLOR/FINISH:
- CHROME
- UNITS:
- EACH
- BORE SIZE METRIC:
- 67.00 MM
- CYLINDER BORE COATING:
- CHROME-MOLY ALLOY
- TYPE:
- AC
- PRODUCT NAME:
- CYLINDER SLEEVE
- RIDING STYLE:
- OFF-ROAD
$153.95 -
L.A. Sleeve Cylinder Sleeve 47.50mm Bore Suzuki RM80 1991-2001 FL5140
LA SLEEVE
$117.95A worn cylinder sleeve compromises compression, increases blow-by, and robs your RM80 of power and efficiency. The L.A. Sleeve FL5140 restores your engine to factory specifications with a precision-engineered replacement that handles the demands of trail...FL5140- SKU:
- FL5140
- Availability:
- Ships Same Business Day
- Weight:
- 0.88 LBS
- BORE SIZE METRIC:
- 47.50 MM
- PRODUCT NAME:
- CYLINDER SLEEVE
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- CS
- COLOR/FINISH:
- CHROME
- UNITS:
- EACH
- CYLINDER BORE COATING:
- CHROME-MOLY ALLOY
$117.95 -
L.A. Sleeve Cylinder Sleeve for Suzuki RM-250 1991-1993 FL5182
LA SLEEVE
$153.95A worn cylinder wall compromises combustion efficiency, power output, and fuel economy—problems that multiply quickly in a high-revving two-stroke like the RM-250. The L.A. Sleeve FL5182 restores your cylinder to factory specifications, eliminating...FL5182- SKU:
- FL5182
- Availability:
- Ships Same Business Day
- Weight:
- 1.25 LBS
- CYLINDER BORE COATING:
- CHROME-MOLY ALLOY
- TYPE:
- AC
- BORE SIZE METRIC:
- 67.00 MM
- PRODUCT NAME:
- CYLINDER SLEEVE
- RIDING STYLE:
- OFF-ROAD
- COLOR/FINISH:
- CHROME
- UNITS:
- EACH
$153.95Qty in Cart: 0Quantity:Price:$153.95Subtotal: -
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 -
On Sale
Cylinder Works Standard Bore Cylinder KTM 50 SX 2009-2023 CW50012
CYLINDER WORKS
MSRP: $434.95Now: $391.46Was: $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
MSRP: $434.95Now: $391.46Was: $434.95 -
On Sale
Cylinder Works Standard Bore Cylinder for Polaris RZR 900 2017-2020 CW60007
CYLINDER WORKS
MSRP: $696.95Now: $627.26Was: $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
MSRP: $696.95Now: $627.26Was: $696.95 -
On Sale
Cylinder Works Yamaha WR250F 2018-2019 High Compression Cylinder Kit 20010-K02HC
CYLINDER WORKS
MSRP: $750.95Now: $675.86Was: $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
MSRP: $750.95Now: $675.86Was: $750.95 -
On Sale
Cylinder Works Standard Bore Cylinder Kit for 2007-2008 Honda CRF450R 10002-K02
CYLINDER WORKS
MSRP: $651.95Now: $586.76Was: $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
MSRP: $651.95Now: $586.76Was: $651.95 -
On Sale
Cylinder Works Big Bore Cylinder Kit for Honda CRF450R 2007-2019 10002-K02HC
CYLINDER WORKS
MSRP: $690.95Now: $621.86Was: $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
MSRP: $690.95Now: $621.86Was: $690.95 -
On Sale
Cylinder Works Standard Bore Cylinder Kit Arctic Cat 400 DVX 2004-2008 40001-K02
CYLINDER WORKS
MSRP: $717.95Now: $646.16Was: $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
MSRP: $717.95Now: $646.16Was: $717.95 -
On Sale
Cylinder Works Standard Bore High Compression Cylinder Kit for 2004-2008 Arctic Cat 400 DVX 40001-K02HC
CYLINDER WORKS
MSRP: $716.95Now: $645.26Was: $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
MSRP: $716.95Now: $645.26Was: $716.95 -
On Sale
Cylinder Works Standard Bore Cylinder Kit for 2018-2019 Honda CRF250R CW10011K01
CYLINDER WORKS
MSRP: $622.95Now: $560.66Was: $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
MSRP: $622.95Now: $560.66Was: $622.95 -
On Sale
Cylinder Works High Compression Cylinder Kit Honda CRF250R 2018-2019 CW10011K01HC
CYLINDER WORKS
MSRP: $664.95Now: $598.46Was: $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
MSRP: $664.95Now: $598.46Was: $664.95 -
On Sale
Cylinder Works Big Bore Cylinder Kit Honda CRF250R 2018-2021 CRF250RX 2019-2021 CW11011K01
CYLINDER WORKS
MSRP: $787.95Now: $709.16Was: $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
MSRP: $787.95Now: $709.16Was: $787.95 -
On Sale
Cylinder Works Standard Bore Cylinder Yamaha YZ450F 2018-2019 CW20012
CYLINDER WORKS
MSRP: $461.95Now: $415.76Was: $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
MSRP: $461.95Now: $415.76Was: $461.95
