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
-
On Sale
ATHENA Top End Gasket Kit P400270600220/1
ATHENA
MSRP: $51.95Now: $47.00Was: $51.95Specifically designed for the pro, semi-pro and amateur rider who freshens up their engine prior to a race or during midseason. Gives the rider a choice of using standard gas with stock compression, or race gas with a higher compression. Kits do not...09340234- SKU:
- 09340234
- Availability:
- Ships Same Business Day
- Weight:
- 0.15 LBS
- PRODUCT NAME:
- GASKET KIT
- ENGINE TYPE:
- 2-STROKE
- MATERIAL:
- RUBBER
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- TOP END
- UNITS:
- KIT
MSRP: $51.95Now: $47.00Was: $51.95Qty in Cart: 0Quantity:Price:MSRP: $51.95Now: $47.00Was: $51.95Subtotal: -
On Sale
Cylinder Works Standard Bore Cylinder Kit for Polaris ACE 900 EPS 2016 60004-K02
CYLINDER WORKS
MSRP: $1,060.95Now: $954.86Was: $1,060.95Upgrade your engine with the CYLINDER WORKS Standard Bore Cylinder, designed for seamless installation and superior performance. This ready-to-install solution features a perfect match with OEM specifications, ensuring a reliable fit and exceptional...09310734- SKU:
- 09310734
- Availability:
- Ships Same Business Day
- Weight:
- 9.91 LBS
- COMPRESSION RATIO IMPERIAL:
- 10.5:1
- CYLINDER BORE COATING:
- NICKEL-SILICON CARBIDE
- CYLINDER DIAMETER METRIC:
- 93.00 MM
- STYLE:
- STANDARD
- UNITS:
- KIT
- CYLINDER DIAMETER:
- 93,00 MM
- DISPLACEMENT:
- STANDARD
- RIDING STYLE:
- UTV
- ENGINE TYPE:
- 4-CYCLE
- PRODUCT NAME:
- CYLINDER
MSRP: $1,060.95Now: $954.86Was: $1,060.95Qty in Cart: 0Quantity:Price:MSRP: $1,060.95Now: $954.86Was: $1,060.95Subtotal: -
On Sale
Cylinder Works Standard Bore Cylinder Kit for Polaris RZR 900 2015-2016 60004
CYLINDER WORKS
MSRP: $672.95Now: $605.66Was: $672.95Upgrade your engine with the CYLINDER WORKS Cylinder Standard 60004, designed for effortless installation and optimal performance. This high-quality, direct bolt-on cylinder matches the aesthetics of OEM cylinders while providing superior durability...09310733- SKU:
- 09310733
- Availability:
- Ships Same Business Day
- Weight:
- 7.15 LBS
- CYLINDER DIAMETER METRIC:
- 93.00 MM
- UNITS:
- EACH
- ENGINE TYPE:
- 4-CYCLE
- PRODUCT NAME:
- CYLINDER
- CYLINDER DIAMETER:
- 93,00 MM
- RIDING STYLE:
- UTV
- STYLE:
- STANDARD
MSRP: $672.95Now: $605.66Was: $672.95Qty in Cart: 0Quantity:Price:MSRP: $672.95Now: $605.66Was: $672.95Subtotal: -
On Sale
Cylinder Works Big Bore Cylinder Kit Yamaha YZ85 2002-2018 103.5cc 21007-K01
CYLINDER WORKS
MSRP: $885.95Now: $797.36Was: $885.95Upgrade your engine's performance with the CYLINDER WORKS Big Bore Cylinder Kit. Designed for easy installation, this kit offers a seamless fit with no need for re-plating, ensuring your bike runs smoothly and efficiently. With high-quality components...09310346- SKU:
- 09310346
- Availability:
- Ships Same Business Day
- Weight:
- 3.60 LBS
- COMPRESSION RATIO IMPERIAL:
- 8.2:1
- ENGINE TYPE:
- 2-CYCLE
- PRODUCT NAME:
- CYLINDER KIT
- STYLE:
- BIG BORE
- CYLINDER BORE COATING:
- NICKEL-SILICON CARBIDE
- DISPLACEMENT:
- 103.5 CC
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- CYLINDER DIAMETER METRIC:
- 52.50 MM
- CYLINDER DIAMETER:
- 52,50 MM
- OVERBORE METRIC:
- +5.00 MM
MSRP: $885.95Now: $797.36Was: $885.95Qty in Cart: 0Quantity:Price:MSRP: $885.95Now: $797.36Was: $885.95Subtotal: -
On Sale
Cylinder Works Suzuki RM-Z250 2010-2012 Standard Bore Cylinder Kit 40004-K01
CYLINDER WORKS
MSRP: $704.95Now: $634.46Was: $704.95Experience unparalleled performance and reliability with the CYLINDER WORKS Cylinder Kit Standard 40004-K01. Designed as a direct bolt-on replacement, this ready-to-install kit ensures a seamless fit and exceptional durability without the need for...09310343- SKU:
- 09310343
- Availability:
- Ships Same Business Day
- Weight:
- 3.25 LBS
- COMPRESSION RATIO IMPERIAL:
- 13.4:1
- CYLINDER DIAMETER METRIC:
- 77.00 MM
- RIDING STYLE:
- OFF-ROAD
- STYLE:
- STANDARD
- DISPLACEMENT:
- 249 CC
- ENGINE TYPE:
- 4-CYCLE
- CYLINDER BORE COATING:
- NICKEL-SILICON CARBIDE
- CYLINDER DIAMETER:
- 77,00 MM
- PRODUCT NAME:
- CYLINDER KIT
- UNITS:
- KIT
MSRP: $704.95Now: $634.46Was: $704.95 -
On Sale
Cylinder Works Kawasaki KX250F 2009 Standard Bore Cylinder Kit 30004-K01
CYLINDER WORKS
MSRP: $679.95Now: $611.96Was: $679.95Experience enhanced performance and reliability with the Cylinder Works Cylinder Kit. This ready-to-install, direct bolt-on solution is designed to seamlessly replace your OEM cylinders, ensuring a perfect fit without the need for re-plating. Each kit...09310277- SKU:
- 09310277
- Availability:
- Ships Same Business Day
- Weight:
- 3.15 LBS
- COMPRESSION RATIO IMPERIAL:
- 13.2:1
- CYLINDER DIAMETER METRIC:
- 77.00 MM
- RIDING STYLE:
- OFF-ROAD
- DISPLACEMENT:
- 249 CC
- ENGINE TYPE:
- 4-CYCLE
- STYLE:
- STANDARD
- CYLINDER BORE COATING:
- NICKEL-SILICON CARBIDE
- CYLINDER DIAMETER:
- 77,00 MM
- PRODUCT NAME:
- CYLINDER KIT
- UNITS:
- KIT
MSRP: $679.95Now: $611.96Was: $679.95 -
On Sale
ATHENA Cylinder Kit - YZ250F - 83mm P400485100012
ATHENA
MSRP: $1,142.95Now: $1,029.00Was: $1,142.95Kits include aluminum cylinder with nickel-carbide coating designed with larger water jackets, Forged piston with molybdenum coating, Special gasket kit, Easy-to-follow step-by-step installation instructions, All are bolt-on; no machining required09310024- SKU:
- 09310024
- Availability:
- Ships Same Business Day
- Weight:
- 3.68 LBS
- DISPLACEMENT:
- 290 CC
- ENGINE TYPE:
- 4-STROKE
- RIDING STYLE:
- OFF-ROAD
- MATERIAL:
- ALUMINUM
- BORE SIZE METRIC:
- 83.00 MM
- CYLINDER BORE COATING:
- NICKEL-CARBIDE
- PRODUCT NAME:
- CYLINDER KIT
- STYLE:
- BIG BORE
- UNITS:
- KIT
MSRP: $1,142.95Now: $1,029.00Was: $1,142.95Qty in Cart: 0Quantity:Price:MSRP: $1,142.95Now: $1,029.00Was: $1,142.95Subtotal: -
On Sale
Wiseco Valve Kit 2012-2016 KTM 350 EXC-F SVKB6353
WISECO
MSRP: $344.95Now: $293.00Was: $344.95Enhance your engine's performance with the WISECO Valve Kit SVKB6353, a comprehensive solution featuring high-quality valves and springs designed for both intake and exhaust applications. This kit ensures optimal reliability and longevity, making it an...09263086- SKU:
- 09263086
- Availability:
- Ships Same Business Day
- Weight:
- 1.05 LBS
- UNITS:
- KIT
- APPLICATION:
- EXHAUST
- APPLICATION:
- INTAKE
- MATERIAL:
- STEEL
- PRODUCT NAME:
- VALVE KIT
- RIDING STYLE:
- OFF-ROAD
MSRP: $344.95Now: $293.00Was: $344.95Qty in Cart: 0Quantity:Price:MSRP: $344.95Now: $293.00Was: $344.95Subtotal: -
Hot Cams Valve Shim 9.48 x 2.80 for Honda CRF450R 2002-2014 5PK948280
HOT CAMS
$10.95Enhance your engine's performance with the HOT CAMS Valve Shim 9.48 x 2.80, designed for precise adjustments in valve clearance. This 5-pack is an essential addition to your valve shim kits, ensuring optimal functioning and longevity of your engine...09261404- SKU:
- 09261404
- Availability:
- Ships Same Business Day
- Weight:
- 0.06 LBS
- RIDING STYLE:
- ATV
- TYPE:
- VALVE
- VALVE SHIM THICKNESS METRIC:
- 2.80 MM
- RIDING STYLE:
- STREET
- MATERIAL:
- STEEL
- OUTSIDE DIAMETER METRIC:
- 9.48 MM
- RIDING STYLE:
- OFF-ROAD
- RIDING STYLE:
- SNOW
- UNITS:
- 5 PACK
- PRODUCT NAME:
- SHIM
- RIDING STYLE:
- ADVENTURE TOURING / DUAL-SPORT
- RIDING STYLE:
- UTV
- RIDING STYLE:
- WATERCRAFT
$10.95 -
Hot Cams Valve Shim 9.48mm x 2.75mm for Honda CRF450R 2002-2014 5PK948275
HOT CAMS
$10.95Upgrade your engine's performance with the HOT CAMS Valve Shim 9.48 x 2.75 pack. Designed for precision and durability, these replacement shims are essential for maintaining optimal valve clearance in your engine. Perfect for refilling your Valve Shim...09261403- SKU:
- 09261403
- Availability:
- Ships Same Business Day
- Weight:
- 0.05 LBS
- RIDING STYLE:
- ATV
- TYPE:
- VALVE
- MATERIAL:
- STEEL
- OUTSIDE DIAMETER METRIC:
- 9.48 MM
- PRODUCT NAME:
- SHIM
- RIDING STYLE:
- SNOW
- UNITS:
- 5 PACK
- RIDING STYLE:
- STREET
- VALVE SHIM THICKNESS METRIC:
- 2.75 MM
- RIDING STYLE:
- ADVENTURE TOURING / DUAL-SPORT
- RIDING STYLE:
- OFF-ROAD
- RIDING STYLE:
- UTV
- RIDING STYLE:
- WATERCRAFT
$10.95 -
Hot Cams Valve Shim 9.48 x 2.70 for Honda CRF450R 2002-2014 5PK948270
HOT CAMS
$10.95Enhance your engine's performance with the HOT CAMS Valve Shim pack, designed for precision and durability. Each shim measures 9.48 x 2.70 mm, making them ideal for refilling Valve Shim Kits. Ensure optimal valve clearance and improve your engine's...09261402- SKU:
- 09261402
- Availability:
- Ships Same Business Day
- Weight:
- 0.05 LBS
- OUTSIDE DIAMETER METRIC:
- 9.48 MM
- TYPE:
- VALVE
- RIDING STYLE:
- ATV
- RIDING STYLE:
- STREET
- VALVE SHIM THICKNESS METRIC:
- 2.70 MM
- PRODUCT NAME:
- SHIM
- RIDING STYLE:
- SNOW
- UNITS:
- 5 PACK
- MATERIAL:
- STEEL
- RIDING STYLE:
- ADVENTURE TOURING / DUAL-SPORT
- RIDING STYLE:
- OFF-ROAD
- RIDING STYLE:
- UTV
- RIDING STYLE:
- WATERCRAFT
$10.95 -
Hot Cams Valve Shim 9.48mm x 2.50mm for Honda CRF 450R 2002-2014 5PK948250
HOT CAMS
$10.95Enhance your engine's performance with the HOT CAMS Valve Shim pack, designed specifically for refilling your Valve Shim Kits. These high-quality shims ensure optimal valve clearance and longevity, making them an essential component for any serious...09261398- SKU:
- 09261398
- Availability:
- Ships Same Business Day
- Weight:
- 0.05 LBS
- OUTSIDE DIAMETER METRIC:
- 9.48 MM
- RIDING STYLE:
- SNOW
- RIDING STYLE:
- STREET
- UNITS:
- 5 PACK
- VALVE SHIM THICKNESS METRIC:
- 2.50 MM
- RIDING STYLE:
- ADVENTURE TOURING / DUAL-SPORT
- RIDING STYLE:
- ATV
- PRODUCT NAME:
- SHIM
- RIDING STYLE:
- UTV
- RIDING STYLE:
- WATERCRAFT
- TYPE:
- VALVE
- MATERIAL:
- STEEL
- RIDING STYLE:
- OFF-ROAD
$10.95 -
Hot Cams Valve Shim 8.90mm x 2.48mm for KTM 250 SX-F 2005-2011 5PK890248
HOT CAMS
$10.95Enhance your engine's performance with the HOT CAMS Valve Shim 8.90 x 2.48. This 5-pack of replacement shims is designed to refill your Valve Shim Kits, ensuring you maintain optimal valve clearance and engine efficiency. Crafted for durability and...09261368- SKU:
- 09261368
- Availability:
- Ships Same Business Day
- Weight:
- 0.01 LBS
- PRODUCT NAME:
- SHIM
- RIDING STYLE:
- STREET
- RIDING STYLE:
- UTV
- RIDING STYLE:
- WATERCRAFT
- UNITS:
- 5 PACK
- MATERIAL:
- STEEL
- RIDING STYLE:
- ADVENTURE TOURING / DUAL-SPORT
- RIDING STYLE:
- OFF-ROAD
- RIDING STYLE:
- SNOW
- VALVE SHIM THICKNESS METRIC:
- 2.48 MM
- OUTSIDE DIAMETER METRIC:
- 8.90 MM
- RIDING STYLE:
- ATV
- TYPE:
- VALVE
$10.95Qty in Cart: 0Quantity:Price:$10.95Subtotal: -
Hot Cams Valve Shim 8.90mm x 2.44mm for KTM 250 SX-F 2005-2011 5PK890244
HOT CAMS
$10.95Enhance your engine's performance with the HOT CAMS Valve Shim Pack, designed specifically for optimal valve adjustment. This convenient 5-pack allows you to easily refill your Valve Shim Kits, ensuring your engine runs smoothly and efficiently. Built...09261367- SKU:
- 09261367
- Availability:
- Ships Same Business Day
- Weight:
- 0.01 LBS
- PRODUCT NAME:
- SHIM
- RIDING STYLE:
- SNOW
- RIDING STYLE:
- STREET
- RIDING STYLE:
- WATERCRAFT
- UNITS:
- 5 PACK
- VALVE SHIM THICKNESS METRIC:
- 2.44 MM
- RIDING STYLE:
- UTV
- MATERIAL:
- STEEL
- RIDING STYLE:
- ADVENTURE TOURING / DUAL-SPORT
- RIDING STYLE:
- OFF-ROAD
- OUTSIDE DIAMETER METRIC:
- 8.90 MM
- RIDING STYLE:
- ATV
- TYPE:
- VALVE
$10.95Qty in Cart: 0Quantity:Price:$10.95Subtotal: -
Hot Cams Valve Shim 8.90 x 2.28 for KTM 250 SX-F 2005-2011 5PK890228
HOT CAMS
$11.95Enhance your engine's performance with the HOT CAMS Valve Shim pack, designed for precision and durability. This 5-pack of shims is perfect for refilling your Valve Shim Kits, ensuring optimal valve clearance and engine efficiency. Crafted for reliable...09261363- SKU:
- 09261363
- Availability:
- Ships Same Business Day
- Weight:
- 0.02 LBS
- OUTSIDE DIAMETER METRIC:
- 8.90 MM
- PRODUCT NAME:
- SHIM
- RIDING STYLE:
- SNOW
- RIDING STYLE:
- WATERCRAFT
- TYPE:
- VALVE
- UNITS:
- 5 PACK
- RIDING STYLE:
- ATV
- RIDING STYLE:
- STREET
- VALVE SHIM THICKNESS METRIC:
- 2.28 MM
- MATERIAL:
- STEEL
- RIDING STYLE:
- ADVENTURE TOURING / DUAL-SPORT
- RIDING STYLE:
- OFF-ROAD
- RIDING STYLE:
- UTV
$11.95 -
Hot Cams Valve Shim 8.90mm x 2.12mm KTM 250 SX-F 2005-2011 5PK890212
HOT CAMS
$11.95Enhance your engine's performance with the HOT CAMS Valve Shim 8.90 x 2.12 pack. Designed for precision and reliability, these replacement shims are essential for maintaining optimal valve clearance in your engine. Perfect for refilling your Valve Shim...09261359- SKU:
- 09261359
- Availability:
- Ships Same Business Day
- Weight:
- 0.02 LBS
- PRODUCT NAME:
- SHIM
- RIDING STYLE:
- ADVENTURE TOURING / DUAL-SPORT
- RIDING STYLE:
- UTV
- RIDING STYLE:
- WATERCRAFT
- MATERIAL:
- STEEL
- OUTSIDE DIAMETER METRIC:
- 8.90 MM
- RIDING STYLE:
- OFF-ROAD
- RIDING STYLE:
- SNOW
- UNITS:
- 5 PACK
- RIDING STYLE:
- STREET
- VALVE SHIM THICKNESS METRIC:
- 2.12 MM
- RIDING STYLE:
- ATV
- TYPE:
- VALVE
$11.95 -
Hot Cams Valve Shim 8.90 x 2.08 KTM 250 SX-F 2005 5PK890208
HOT CAMS
$11.95Enhance your engine's performance with the HOT CAMS Valve Shim 8.90 x 2.08, designed for precision and reliability. This 5-pack of replacement shims is perfect for refilling your Valve Shim Kits, ensuring optimal valve clearance and engine efficiency...09261358- SKU:
- 09261358
- Availability:
- Ships Same Business Day
- Weight:
- 0.03 LBS
- RIDING STYLE:
- ADVENTURE TOURING / DUAL-SPORT
- RIDING STYLE:
- OFF-ROAD
- RIDING STYLE:
- UTV
- RIDING STYLE:
- WATERCRAFT
- RIDING STYLE:
- STREET
- MATERIAL:
- STEEL
- OUTSIDE DIAMETER METRIC:
- 8.90 MM
- PRODUCT NAME:
- SHIM
- RIDING STYLE:
- SNOW
- UNITS:
- 5 PACK
- RIDING STYLE:
- ATV
- TYPE:
- VALVE
- VALVE SHIM THICKNESS METRIC:
- 2.08 MM
$11.95 -
Hot Cams Valve Shim 7.48mm x 2.90mm for Honda CRF 150R 2007-2018 5PK748290
HOT CAMS
$10.95Elevate your engine's performance with the HOT CAMS Valve Shim 7.48 x 2.90. This 5-pack of precision-engineered shims is designed to refill your Valve Shim Kits, ensuring optimal valve clearance and efficient engine operation. Perfect for both...09261336- SKU:
- 09261336
- Availability:
- Ships Same Business Day
- Weight:
- 0.05 LBS
- MATERIAL:
- STEEL
- RIDING STYLE:
- ADVENTURE TOURING / DUAL-SPORT
- RIDING STYLE:
- OFF-ROAD
- PRODUCT NAME:
- SHIM
- RIDING STYLE:
- UTV
- RIDING STYLE:
- WATERCRAFT
- TYPE:
- VALVE
- UNITS:
- 5 PACK
- OUTSIDE DIAMETER METRIC:
- 7.48 MM
- RIDING STYLE:
- ATV
- RIDING STYLE:
- STREET
- RIDING STYLE:
- SNOW
- VALVE SHIM THICKNESS METRIC:
- 2.90 MM
$10.95Qty in Cart: 0Quantity:Price:$10.95Subtotal: -
Hot Cams Valve Shim 7.48mm x 2.75mm for Honda CRF 150R 2007-2018 5PK748275
HOT CAMS
$10.95Ensure optimal engine performance with the HOT CAMS Valve Shim Replacement Pack. Designed specifically for refilling Valve Shim Kits, these high-quality shims provide precise thickness and durability for reliable valve adjustments. Perfect for both...09261333- SKU:
- 09261333
- Availability:
- Ships Same Business Day
- Weight:
- 0.05 LBS
- TYPE:
- VALVE
- PRODUCT NAME:
- SHIM
- RIDING STYLE:
- SNOW
- UNITS:
- 5 PACK
- OUTSIDE DIAMETER METRIC:
- 7.48 MM
- RIDING STYLE:
- ATV
- RIDING STYLE:
- STREET
- VALVE SHIM THICKNESS METRIC:
- 2.75 MM
- MATERIAL:
- STEEL
- RIDING STYLE:
- ADVENTURE TOURING / DUAL-SPORT
- RIDING STYLE:
- OFF-ROAD
- RIDING STYLE:
- UTV
- RIDING STYLE:
- WATERCRAFT
$10.95Qty in Cart: 0Quantity:Price:$10.95Subtotal: -
Hot Cams Valve Shim 7.48mm x 2.65mm for Honda CRF150R 2007-2018 5PK748265
HOT CAMS
$10.95Enhance your engine's performance with the HOT CAMS Valve Shim 7.48 x 2.65. This 5-pack of high-quality shims is designed to refill your Valve Shim Kits, ensuring optimal valve clearance and improved engine efficiency. Crafted for durability and...09261331- SKU:
- 09261331
- Availability:
- Ships Same Business Day
- Weight:
- 0.05 LBS
- RIDING STYLE:
- ATV
- TYPE:
- VALVE
- MATERIAL:
- STEEL
- RIDING STYLE:
- OFF-ROAD
- RIDING STYLE:
- SNOW
- UNITS:
- 5 PACK
- RIDING STYLE:
- STREET
- OUTSIDE DIAMETER METRIC:
- 7.48 MM
- PRODUCT NAME:
- SHIM
- RIDING STYLE:
- ADVENTURE TOURING / DUAL-SPORT
- RIDING STYLE:
- UTV
- RIDING STYLE:
- WATERCRAFT
- VALVE SHIM THICKNESS METRIC:
- 2.65 MM
$10.95
