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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LA Sleeve Sleeve and Piston Kit Kawasaki KX250F 2009-2016 LAS-5611K-1
LA SLEEVE
$375.95Elevate your Kawasaki's performance with the LA SLEEVE Sleeve and Piston Kit, designed for optimal power and efficiency. This comprehensive top-end rebuild kit features advanced materials and...09310519- SKU:
- 09310519
- Availability:
- Ships Same Business Day
- Weight:
- 2.45 LBS
- MATERIAL:
- IRON
- PRODUCT NAME:
- REBUILD KIT
- TYPE:
- CYLINDER
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
$375.95Qty in Cart: 0Quantity:Price:$375.95Subtotal: -
LA Sleeve Cylinder Sleeve for Honda XR400R 1996-2004 H5293
LA SLEEVE
$111.95Revitalize your engine with the LA SLEEVE Cylinder Sleeve H5293, designed to restore performance and extend the lifespan of your cylinders. Crafted from high-quality materials, these sleeves provide...H5293- SKU:
- H5293
- Availability:
- Ships Same Business Day
- Weight:
- 1.80 LBS
- COLOR/FINISH:
- ALUMINUM
- PRODUCT NAME:
- CYLINDER SLEEVE
- RIDING STYLE:
- ATV
- UNITS:
- EACH
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- RS
- BORE SIZE METRIC:
- 85.00 MM
- CYLINDER BORE COATING:
- CHROME-MOLY ALLOY
$111.95 -
LA Sleeve Cylinder Sleeve 72mm Bore Polaris Trail Blazer 250 1990-2006 FL5168
LA SLEEVE
$148.95Revitalize your engine with the LA SLEEVE Cylinder Sleeve FL5168, designed to restore performance and extend the lifespan of your old cylinders. Crafted with precision, these high-quality replacement...FL5168- SKU:
- FL5168
- Availability:
- Ships Same Business Day
- Weight:
- 1.00 LBS
- COLOR/FINISH:
- ALUMINUM
- CYLINDER BORE COATING:
- CHROME-MOLY ALLOY
- PRODUCT NAME:
- CYLINDER SLEEVE
- TYPE:
- CI
- BORE SIZE METRIC:
- 72.00 MM
- RIDING STYLE:
- ATV
- UNITS:
- EACH
$148.95 -
LA Sleeve Cylinder Sleeve Yamaha YZ250 1996 YA5296
LA SLEEVE
$148.95A worn or damaged cylinder sleeve compromises compression, increases blow-by, and accelerates piston ring wear—ultimately robbing your YZ250 of power and reliability. This LA Sleeve replacement...YA5296- SKU:
- YA5296
- Availability:
- Ships Same Business Day
- Weight:
- 1.12 LBS
- COLOR/FINISH:
- CHROME
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- EACH
- BORE SIZE METRIC:
- 68.00 MM
- CYLINDER BORE COATING:
- CHROME-MOLY ALLOY
- PRODUCT NAME:
- CYLINDER SLEEVE
- TYPE:
- AC
$148.95Qty in Cart: 0Quantity:Price:$148.95Subtotal: -
LA Sleeve Big Bore Cylinder Sleeve for Honda TRX400EX 1999-2008 H5445
LA SLEEVE
$117.95If your TRX400EX is showing signs of cylinder wear—loss of compression, blow-by, or hard starting—a sleeve replacement restores factory performance without the cost of a full engine rebuild. The LA...09310054- SKU:
- 09310054
- Availability:
- Ships Same Business Day
- Weight:
- 1.86 LBS
- BORE SIZE METRIC:
- 88.00 MM
- COLOR/FINISH:
- ALUMINUM
- RIDING STYLE:
- ATV
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- EACH
- PRODUCT NAME:
- CYLINDER SLEEVE
- TYPE:
- BIG BORE
- CYLINDER BORE COATING:
- CHROME-MOLY ALLOY
$117.95Qty in Cart: 0Quantity:Price:$117.95Subtotal: -
KIBBLEWHITE Intake Valve Kit 80-80970
KIBBLEWHITE
$261.51Valve train durability is the foundation of reliable engine performance, and OEM titanium intake valves can only take you so far before wear compromises your build. The KIBBLEWHITE Black Diamond...09262678- SKU:
- 09262678
- Availability:
- Ships Same Business Day
- Weight:
- 0.35 LBS
- SPRING OPEN PRESSURE:
- 151 LB
- TYPE:
- CONVERSION
- MATERIAL:
- TITANIUM
- SPRING LIFT:
- 0,425'
- SPRING SEAT PRESSURE:
- 48 LB
- PRODUCT NAME:
- VALVE KIT
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- APPLICATION:
- INTAKE
- SPRING LIFT IMPERIAL:
- 0.425'
$261.51Qty in Cart: 0Quantity:Price:$261.51Subtotal: -
KIBBLEWHITE Valve Spring Kit 96-96400
KIBBLEWHITE
$220.26Valve spring performance is critical to engine reliability and RPM capability—inadequate springs lead to valve float, loss of power, and catastrophic engine damage. The KIBBLEWHITE Valve Spring Kit...09262704- SKU:
- 09262704
- Availability:
- Ships Same Business Day
- Weight:
- 0.50 LBS
- APPLICATION:
- EXHAUST
- APPLICATION:
- INTAKE
- PRODUCT NAME:
- SPRING KIT
- SPRING LIFT IMPERIAL:
- 0.450'
- TYPE:
- VALVE
- MATERIAL:
- TITANIUM
- RIDING STYLE:
- OFF-ROAD
- SPRING OPEN PRESSURE:
- 165 LB
- UNITS:
- KIT
$220.26Qty in Cart: 0Quantity:Price:$220.26Subtotal: -
KIBBLEWHITE Intake Valve - Titanium - KTM 96-96412T
KIBBLEWHITE
$109.33Titanium intake valves are essential for high-RPM engines where thermal expansion and weight savings directly impact performance and reliability. The Kibblewhite Tensilite® design reduces inertial...09262706- SKU:
- 09262706
- Availability:
- Ships Same Business Day
- Weight:
- 0.05 LBS
- MATERIAL:
- TITANIUM
- MODEL:
- TENSILITE®
- APPLICATION:
- INTAKE
- HEAD DIAMETER METRIC:
- 32.51 MM
- PRODUCT NAME:
- VALVE
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- EACH
- STEM DIAMETER IMPERIAL:
- 0.1960'
- TULIP ANGLE:
- 15°
$109.33 -
KIBBLEWHITE Intake Valve 80-8055H
KIBBLEWHITE
$54.10Intake valves are critical to engine reliability and performance—they're the gateway to your combustion chamber, and any weakness here translates to lost horsepower and potential catastrophic failure...KW808055H- SKU:
- KW808055H
- Availability:
- Ships Same Business Day
- Weight:
- 0.05 LBS
- STEM DIAMETER IMPERIAL:
- 0.1765'
- HEAD DIAMETER METRIC:
- 27.00 MM
- LENGTH IMPERIAL:
- 3.320'
- MATERIAL:
- STEEL
- PRODUCT NAME:
- VALVE
- SIZE METRIC:
- STANDARD
- APPLICATION:
- INTAKE
- UNITS:
- EACH
- MODEL:
- WHITE DIAMOND™
- RIDING STYLE:
- OFF-ROAD
- TULIP ANGLE:
- 15°
$54.10 -
KIBBLEWHITE Intake Valve Guide 30-30930
KIBBLEWHITE
$15.92Valve guides are critical to controlling oil consumption and maintaining precise valve seat alignment under extreme combustion pressures. A worn or damaged guide compromises engine sealing, increases...09260412- SKU:
- 09260412
- Availability:
- Ships Same Business Day
- Weight:
- 0.11 LBS
- INSIDE DIAMETER IMPERIAL:
- 0.2155'
- APPLICATION:
- INTAKE
- PRODUCT NAME:
- VALVE GUIDE
- RIDING STYLE:
- ATV
- UNITS:
- EACH
- MATERIAL:
- C630 BRONZE
- OUTSIDE DIAMETER IMPERIAL:
- 0.4360'
- SIZE IMPERIAL:
- STANDARD
$15.92 -
KIBBLEWHITE Intake Valve Guide 30-31170
KIBBLEWHITE
$15.92Valve guide wear is one of the most common causes of oil consumption and reduced engine efficiency in high-performance applications. The KIBBLEWHITE Intake Valve Guide 30-31170 delivers superior heat...09260438- SKU:
- 09260438
- Availability:
- Ships Same Business Day
- Weight:
- 0.01 LBS
- INSIDE DIAMETER IMPERIAL:
- 0.1960'
- MATERIAL:
- C630 BRONZE
- RIDING STYLE:
- OFF-ROAD
- APPLICATION:
- INTAKE
- OUTSIDE DIAMETER IMPERIAL:
- 0.3965'
- SIZE IMPERIAL:
- STANDARD
- UNITS:
- EACH
- PRODUCT NAME:
- VALVE GUIDE
$15.92Qty in Cart: 0Quantity:Price:$15.92Subtotal: -
KIBBLEWHITE Exhaust Valve 30-3117
KIBBLEWHITE
$37.55Exhaust valves endure extreme heat cycles and aggressive combustion pressures—factory originals often become the weak link in high-performance builds. The KIBBLEWHITE Black Diamond™ Exhaust Valve...KW303117- SKU:
- KW303117
- Availability:
- Ships Same Business Day
- Weight:
- 0.13 LBS
- MODEL:
- BLACK DIAMOND™
- TULIP ANGLE:
- 29°
- LENGTH IMPERIAL:
- 3.980'
- MATERIAL:
- STAINLESS STEEL
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- EACH
- APPLICATION:
- EXHAUST
- HEAD DIAMETER METRIC:
- 29.00 MM
- PRODUCT NAME:
- VALVE
- RIDING STYLE:
- ATV
- STEM DIAMETER IMPERIAL:
- 0.2150'
$37.55 -
KIBBLEWHITE Cast Iron Valve Seat 10-SC280
KIBBLEWHITE
$8.12Valve seat recession is one of the fastest ways to lose compression and combustion efficiency in high-performance engines—especially when running aggressive fuel blends or boost. KIBBLEWHITE's Cast...09261630- SKU:
- 09261630
- Availability:
- Ships Same Business Day
- Weight:
- 0.07 LBS
- VALVE SEAT HEIGHT METRIC:
- 9.50 MM
- HEAD DIAMETER METRIC:
- 28.00 MM
- INSIDE DIAMETER METRIC:
- 20.00 MM
- MATERIAL:
- STEEL
- OUTSIDE DIAMETER METRIC:
- 28.00 MM
- RIDING STYLE:
- OFF-ROAD
- APPLICATION:
- EXHAUST
- PRODUCT NAME:
- VALVE SEAT
- UNITS:
- EACH
$8.12 -
KIBBLEWHITE Cast Iron Valve Seat 10-SC350
KIBBLEWHITE
$9.02Valve seat recession and microwelding failure can cost you a race—or worse, leave you stranded on the street. KIBBLEWHITE's cast iron valve seats are engineered with powdered metal technology to...09261636- SKU:
- 09261636
- Availability:
- Ships Same Business Day
- Weight:
- 0.07 LBS
- INSIDE DIAMETER METRIC:
- 26.00 MM
- UNITS:
- EACH
- APPLICATION:
- EXHAUST
- OUTSIDE DIAMETER METRIC:
- 35.00 MM
- HEAD DIAMETER METRIC:
- 35.00 MM
- PRODUCT NAME:
- VALVE SEAT
- MATERIAL:
- STEEL
- RIDING STYLE:
- OFF-ROAD
- VALVE SEAT HEIGHT METRIC:
- 10.00 MM
$9.02Qty in Cart: 0Quantity:Price:$9.02Subtotal: -
KIBBLEWHITE Valve Guide - Intake 96-96520-I
KIBBLEWHITE
$22.95Valve guides are critical to maintaining proper valve stem clearance and preventing oil seepage into your combustion chamber—a worn guide will compromise both performance and engine longevity. The...09263045- SKU:
- 09263045
- Availability:
- Ships Same Business Day
- Weight:
- 0.06 LBS
- MATERIAL:
- CAST IRON
- OUTSIDE DIAMETER IMPERIAL:
- 0.4352'
- APPLICATION:
- INTAKE
- PRODUCT NAME:
- VALVE GUIDE
- SIZE IMPERIAL:
- STANDARD
- UNITS:
- EACH
- INSIDE DIAMETER IMPERIAL:
- 0.2353'
- RIDING STYLE:
- OFF-ROAD
$22.95 -
KIBBLEWHITE Intake Valve Guide 80-80110
KIBBLEWHITE
$22.29Valve guides are critical to engine longevity—they maintain precise valve alignment, prevent wear on valve stems, and directly impact combustion efficiency and port flow. The KIBBLEWHITE 80-80110 is...09263097- SKU:
- 09263097
- Availability:
- Ships Same Business Day
- Weight:
- 0.06 LBS
- APPLICATION:
- INTAKE
- UNITS:
- EACH
- BASE COLOR:
- BROWN
- PRODUCT NAME:
- VALVE GUIDE
- MATERIAL:
- C630 BRONZE
- OUTSIDE DIAMETER IMPERIAL:
- 0.3957'
- RIDING STYLE:
- OFF-ROAD
- COLOR/FINISH:
- BRONZE
- INSIDE DIAMETER IMPERIAL:
- 0.1765'
- SIZE IMPERIAL:
- STANDARD
$22.29 -
KIBBLEWHITE Cylinder Head Service Kit 30-33310
KIBBLEWHITE
$466.90A complete cylinder head refresh demands precision components that work in concert—and the KIBBLEWHITE 30-33310 Service Kit delivers exactly that. This comprehensive kit eliminates the guesswork of...09263117- SKU:
- 09263117
- Availability:
- Ships Same Business Day
- Weight:
- 1.05 LBS
- MATERIAL:
- TITANIUM
- SPRING SEAT PRESSURE:
- 50 LB
- UNITS:
- KIT
- APPLICATION:
- EXHAUST
- SPRING LIFT:
- 0,385'
- MATERIAL:
- C630 BRONZE
- RIDING STYLE:
- OFF-ROAD
- SPRING LIFT IMPERIAL:
- 0.385'
- SPRING OPEN PRESSURE:
- 160 LB
- APPLICATION:
- INTAKE
- MODEL:
- BLACK DIAMOND™
- PRODUCT NAME:
- CYLINDER HEAD SERVICE KIT
$466.90Qty in Cart: 0Quantity:Price:$466.90Subtotal: -
KIBBLEWHITE Spring Kit 30-32400
KIBBLEWHITE
$229.93A properly engineered valve spring kit is essential for maintaining consistent valve seating, preventing float at high RPMs, and ensuring reliable performance under sustained load. The KIBBLEWHITE...09262980- SKU:
- 09262980
- Availability:
- Ships Same Business Day
- Weight:
- 0.50 LBS
- APPLICATION:
- INTAKE
- RIDING STYLE:
- OFF-ROAD
- SPRING OPEN PRESSURE:
- 160 LB
- TYPE:
- VALVE
- UNITS:
- KIT
- MATERIAL:
- TITANIUM
- PRODUCT NAME:
- SPRING KIT
- SPRING LIFT IMPERIAL:
- 0.380'
- APPLICATION:
- EXHAUST
$229.93Qty in Cart: 0Quantity:Price:$229.93Subtotal: -
KIBBLEWHITE Exhaust Valve 30-32416
KIBBLEWHITE
$37.55Exhaust valves are critical components that directly impact engine efficiency, reliability, and longevity. The KIBBLEWHITE Black Diamond™ 30-32416 is engineered to withstand extreme temperatures and...09262983- SKU:
- 09262983
- Availability:
- Ships Same Business Day
- Weight:
- 0.01 LBS
- HEAD DIAMETER METRIC:
- 25.00 MM
- MATERIAL:
- STAINLESS STEEL
- PRODUCT NAME:
- VALVE
- TULIP ANGLE:
- 20°
- UNITS:
- EACH
- APPLICATION:
- EXHAUST
- MODEL:
- BLACK DIAMOND™
- LENGTH IMPERIAL:
- 3.310'
- RIDING STYLE:
- OFF-ROAD
- STEM DIAMETER IMPERIAL:
- 0.1956'
$37.55 -
KIBBLEWHITE Exhaust Valve - Stantard - Tensilite‚® - CRF250R 30-32416T
KIBBLEWHITE
$109.33Exhaust valve performance directly impacts your CRF250R's scavenging efficiency and peak horsepower delivery. KIBBLEWHITE's Tensilite® valves are precision-forged from aerospace-grade titanium and...09262986- SKU:
- 09262986
- Availability:
- Ships Same Business Day
- Weight:
- 0.05 LBS
- APPLICATION:
- EXHAUST
- RIDING STYLE:
- OFF-ROAD
- STEM DIAMETER IMPERIAL:
- 0.1956'
- PRODUCT NAME:
- VALVE
- TULIP ANGLE:
- 20°
- HEAD DIAMETER METRIC:
- 25.00 MM
- MATERIAL:
- TITANIUM
- MODEL:
- TENSILITE®
- UNITS:
- EACH
$109.33Qty in Cart: 0Quantity:Price:$109.33Subtotal:
