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!
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- Price
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Hot Cams Stage 1 Intake Camshaft for 2004-2009 Kawasaki KX250F 2004-2007 Suzuki RM-Z250 2041-1IN
HOT CAMS
$272.95If you're running a KX250F or RM-Z250 in competitive racing or serious trail riding, camshaft selection directly determines your power delivery and throttle response. The Hot Cams Stage 1 intake camshaft gives you a genuine upgrade path without the...09250050- SKU:
- 09250050
- Availability:
- Ships Same Business Day
- Weight:
- 0.88 LBS
- TYPE:
- STAGE 1
- PRODUCT NAME:
- CAMSHAFT
- RIDING STYLE:
- OFF-ROAD
- APPLICATION:
- INTAKE
- INTAKE DURATION IMPERIAL:
- 253°
- INTAKE LIFT METRIC:
- 9.14 MM
- UNITS:
- EACH
$272.95 -
Hot Cams Exhaust Camshaft for Kawasaki KX250F 2004-2010 2040-1E
HOT CAMS
$272.95If you're serious about KX250F performance, your stock exhaust cam is leaving horsepower on the table. The Hot Cams 2040-1E is purpose-built to unlock measurable gains in torque and peak power, giving you the edge in competitive racing and aggressive...09250051- SKU:
- 09250051
- Availability:
- Ships Same Business Day
- Weight:
- 1.11 LBS
- EXHAUST DURATION IMPERIAL:
- 244°
- EXHAUST LIFT METRIC:
- 7.98 MM
- TYPE:
- STAGE 1
- APPLICATION:
- EXHAUST
- PRODUCT NAME:
- CAMSHAFT
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- EACH
$272.95 -
Hot Cams Stage 3 Camshaft for Honda CRF450R 2002-2006 1056-3
HOT CAMS
$432.95The Hot Cams Stage 3 Camshaft unlocks measurable gains in mid-range torque and top-end horsepower for your CRF450R, whether you're competing on the track or pushing your bike to its limits on the trail. This drop-in upgrade works seamlessly with your...09250084- SKU:
- 09250084
- Availability:
- Ships Same Business Day
- Weight:
- 0.96 LBS
- PRODUCT NAME:
- CAMSHAFT
- RIDING STYLE:
- ATV
- APPLICATION:
- EXHAUST
- EXHAUST DURATION IMPERIAL:
- 265°
- EXHAUST LIFT METRIC:
- 9.10 MM
- APPLICATION:
- INTAKE
- UNITS:
- EACH
- INTAKE DURATION IMPERIAL:
- 254°
- INTAKE LIFT METRIC:
- 10.40 MM
- TYPE:
- STAGE 3
$432.95 -
Hot Cams Stage 1 Exhaust Camshaft Yamaha YZ450F 2003-2009 4022-1E
HOT CAMS
$310.95If you're serious about extracting every bit of performance from your YZ450F, a quality camshaft swap is one of the highest-ROI modifications you can make. The Hot Cams Stage 1 Exhaust Camshaft is engineered specifically to build low-to-mid range torque,...09250035- SKU:
- 09250035
- Availability:
- Ships Same Business Day
- Weight:
- 1.00 LBS
- PRODUCT NAME:
- CAMSHAFT
- TYPE:
- STAGE 1
- UNITS:
- EACH
- EXHAUST DURATION IMPERIAL:
- 265°
- EXHAUST LIFT METRIC:
- 8.67 MM
- RIDING STYLE:
- OFF-ROAD
- APPLICATION:
- EXHAUST
$310.95 -
Hot Cams Steel Exhaust Valve for Honda CRF450R 2002-2006 8400002-1
HOT CAMS
$51.95If you're running a CRF450R at the edge of its limits, your stock exhaust valve is costing you power and reliability. Hot Cams' one-piece forged construction delivers the durability and precision flow characteristics you need for sustained high-RPM...09262904- SKU:
- 09262904
- Availability:
- Ships Same Business Day
- Weight:
- 0.10 LBS
- COLOR/FINISH:
- BLACK
- LENGTH METRIC:
- 84 MM
- APPLICATION:
- EXHAUST
- STEM DIAMETER METRIC:
- 4.970 MM
- OUTSIDE DIAMETER METRIC:
- 31.00 MM
- UNITS:
- EACH
- BASE COLOR:
- BLACK
- MATERIAL:
- STEEL
- PRODUCT NAME:
- VALVE
- RIDING STYLE:
- OFF-ROAD
$51.95 -
Hot Cams Exhaust Valve for 2007-2008 Honda CRF450R 8400002-5
HOT CAMS
$53.95The stock exhaust valve on your 2007-2008 Honda CRF450R is a wear item that directly impacts combustion efficiency, valve sealing, and engine longevity. A forged, precision-machined replacement like the HOT CAMS 8400002-5 restores lost performance and...09262905- SKU:
- 09262905
- Availability:
- Ships Same Business Day
- Weight:
- 0.10 LBS
- RIDING STYLE:
- OFF-ROAD
- APPLICATION:
- EXHAUST
- STEM DIAMETER METRIC:
- 4.970 MM
- BASE COLOR:
- BLACK
- LENGTH METRIC:
- 84 MM
- MATERIAL:
- STEEL
- PRODUCT NAME:
- VALVE
- COLOR/FINISH:
- BLACK
- OUTSIDE DIAMETER METRIC:
- 30 MM
- UNITS:
- EACH
$53.95 -
Hot Cams Steel Exhaust Valve 1999-2008 Honda TRX400EX 8400003-1
HOT CAMS
$48.95Your TRX400EX's exhaust valve is subjected to extreme heat cycles and high RPM stress—factory valves wear quickly under aggressive use or tuning. The Hot Cams Steel Exhaust Valve restores precision sealing and durability, ensuring consistent performance...09262906- SKU:
- 09262906
- Availability:
- Ships Same Business Day
- Weight:
- 0.15 LBS
- COLOR/FINISH:
- BLACK
- OUTSIDE DIAMETER METRIC:
- 29.00 MM
- STEM DIAMETER METRIC:
- 5.460 MM
- APPLICATION:
- EXHAUST
- LENGTH METRIC:
- 101 MM
- RIDING STYLE:
- ATV
- UNITS:
- EACH
- BASE COLOR:
- BLACK
- MATERIAL:
- STEEL
- PRODUCT NAME:
- VALVE
- RIDING STYLE:
- OFF-ROAD
$48.95 -
Hot Cams Steel Intake Valve for Honda TRX400EX 1999-2008 8400003-2
HOT CAMS
$31.95The factory intake valve on your TRX400EX will eventually wear, restricting airflow and compromising engine efficiency. This Hot Cams replacement restores optimal valve sealing while adding durability upgrades that handle sustained high-RPM performance...09262907- SKU:
- 09262907
- Availability:
- Ships Same Business Day
- Weight:
- 0.11 LBS
- RIDING STYLE:
- OFF-ROAD
- LENGTH METRIC:
- 103 MM
- BASE COLOR:
- BLACK
- MATERIAL:
- STEEL
- PRODUCT NAME:
- VALVE
- APPLICATION:
- INTAKE
- COLOR/FINISH:
- BLACK
- OUTSIDE DIAMETER METRIC:
- 33.00 MM
- RIDING STYLE:
- ATV
- STEM DIAMETER METRIC:
- 5.480 MM
- UNITS:
- EACH
$31.95 -
Hot Cams Steel Exhaust Valve for Suzuki DR-Z400S 2000-2009 2011-2017 8400009-1
HOT CAMS
$69.95The OEM exhaust valve is one of the most critical wear items in your DR-Z400S engine. Over time, carbon buildup, heat cycling, and seat erosion degrade sealing integrity, causing compression loss, reduced power, and rough idle. The HOT CAMS Exhaust Valve...09262908- SKU:
- 09262908
- Availability:
- Ships Same Business Day
- Weight:
- 0.11 LBS
- MATERIAL:
- STEEL
- RIDING STYLE:
- OFF-ROAD
- COLOR/FINISH:
- BLACK
- LENGTH METRIC:
- 81.00 MM
- RIDING STYLE:
- ADVENTURE TOURING / DUAL-SPORT
- UNITS:
- EACH
- APPLICATION:
- EXHAUST
- BASE COLOR:
- BLACK
- OUTSIDE DIAMETER METRIC:
- 29.00 MM
- PRODUCT NAME:
- VALVE
- STEM DIAMETER METRIC:
- 4.960 MM
$69.95 -
Hot Cams Steel Intake Valve for Suzuki DR-Z400S 2000-2009 8400009-2
HOT CAMS
$53.95The intake valve is critical to your DR-Z400S's breathing efficiency—a worn or stock valve restricts airflow and limits power potential. HOT CAMS' forged steel construction and precision engineering deliver the reliability and performance gains you need...09262909- SKU:
- 09262909
- Availability:
- Ships Same Business Day
- Weight:
- 0.16 LBS
- APPLICATION:
- INTAKE
- MATERIAL:
- STEEL
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- EACH
- LENGTH METRIC:
- 82.00 MM
- BASE COLOR:
- BLACK
- OUTSIDE DIAMETER METRIC:
- 36.00 MM
- PRODUCT NAME:
- VALVE
- STEM DIAMETER METRIC:
- 4.980 MM
- COLOR/FINISH:
- BLACK
- RIDING STYLE:
- ADVENTURE TOURING / DUAL-SPORT
$53.95 -
Hot Cams Exhaust Valve for Honda CRF150R 2007-2023 8400020-1
HOT CAMS
$40.95The exhaust valve is critical to your CRF150R's combustion cycle—when it wears, you lose power, efficiency, and reliability. HOT CAMS' forged construction and precision engineering deliver the durability needed for consistent performance, whether you're...09262910- SKU:
- 09262910
- Availability:
- Ships Same Business Day
- Weight:
- 0.05 LBS
- MATERIAL:
- STEEL
- RIDING STYLE:
- OFF-ROAD
- APPLICATION:
- EXHAUST
- BASE COLOR:
- BLACK
- PRODUCT NAME:
- VALVE
- COLOR/FINISH:
- BLACK
- LENGTH METRIC:
- 80 MM
- OUTSIDE DIAMETER METRIC:
- 22.50 MM
- STEM DIAMETER METRIC:
- 4.470 MM
- UNITS:
- EACH
$40.95 -
Hot Cams Steel Intake Valve for Honda CRF150R 2007-2021 8400020-2
HOT CAMS
$29.95The intake valve is critical to your CRF150R's breathing efficiency—a worn or stock valve directly limits combustion chamber sealing and power delivery. Hot Cams' forged, nitride-coated design eliminates the weak points of OEM valves, delivering...09262911- SKU:
- 09262911
- Availability:
- Ships Same Business Day
- Weight:
- 0.05 LBS
- STEM DIAMETER METRIC:
- 4.48 MM
- RIDING STYLE:
- OFF-ROAD
- APPLICATION:
- INTAKE
- COLOR/FINISH:
- BLACK
- UNITS:
- EACH
- BASE COLOR:
- BLACK
- MATERIAL:
- STEEL
- PRODUCT NAME:
- VALVE
$29.95 -
Hot Cams Exhaust Valve Steel for Honda CRF450R 2009-2012 8400027-1
HOT CAMS
$50.95Your CRF450R's exhaust valve is critical to cylinder sealing and engine efficiency—a worn or damaged valve directly compromises power output and reliability. Hot Cams' forged exhaust valve delivers OEM-compatible performance with enhanced durability...09262912- SKU:
- 09262912
- Availability:
- Ships Same Business Day
- Weight:
- 0.10 LBS
- APPLICATION:
- EXHAUST
- STEM DIAMETER METRIC:
- 4.970 MM
- COLOR/FINISH:
- BLACK
- BASE COLOR:
- BLACK
- MATERIAL:
- STEEL
- PRODUCT NAME:
- VALVE
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- EACH
$50.95 -
Hot Cams Steel Exhaust Valve Honda CRF250R 2010-2015 8400032-1
HOT CAMS
$51.95Factory exhaust valves wear under high RPM loads, causing compression loss and erratic idle quality. The HOT CAMS forged exhaust valve restores precise sealing and valve timing stability, directly improving throttle response and engine longevity. If...09262914- SKU:
- 09262914
- Availability:
- Ships Same Business Day
- Weight:
- 0.05 LBS
- COLOR/FINISH:
- BLACK
- APPLICATION:
- EXHAUST
- BASE COLOR:
- BLACK
- PRODUCT NAME:
- VALVE
- STEM DIAMETER METRIC:
- 4.470 MM
- UNITS:
- EACH
- MATERIAL:
- STEEL
- RIDING STYLE:
- OFF-ROAD
$51.95 -
Hot Cams Steel Exhaust Valve for 2000-2006 KTM 400 EXC 8400038-1
HOT CAMS
$64.95If you're running a 2000-2006 KTM 400 EXC, valve wear directly impacts combustion efficiency and engine longevity. The HOT CAMS Steel Exhaust Valve (8400038-1) is engineered as a direct OEM replacement that restores precise sealing and thermal...09262915- SKU:
- 09262915
- Availability:
- Ships Same Business Day
- Weight:
- 0.15 LBS
- COLOR/FINISH:
- BLACK
- BASE COLOR:
- BLACK
- MATERIAL:
- STEEL
- PRODUCT NAME:
- VALVE
- RIDING STYLE:
- ATV
- UNITS:
- EACH
- APPLICATION:
- EXHAUST
- RIDING STYLE:
- OFF-ROAD
- STEM DIAMETER METRIC:
- 5.96 MM
$64.95 -
Hot Cams Steel Intake Valve for 2008-2009 KTM 450 XC 8400038-2
HOT CAMS
$40.95The intake valve is critical to your 450 XC's combustion efficiency and overall engine reliability. Factory valves wear under aggressive racing conditions, compromising sealing and airflow—exactly where HOT CAMS' forged construction and nitride coating...09262916- SKU:
- 09262916
- Availability:
- Ships Same Business Day
- Weight:
- 0.15 LBS
- COLOR/FINISH:
- BLACK
- APPLICATION:
- INTAKE
- BASE COLOR:
- BLACK
- MATERIAL:
- STEEL
- PRODUCT NAME:
- VALVE
- RIDING STYLE:
- ATV
- STEM DIAMETER METRIC:
- 5.97 MM
- UNITS:
- EACH
- RIDING STYLE:
- OFF-ROAD
$40.95 -
Hot Cams Stage 2 Intake Camshaft for 2017-2018 Kawasaki KX250F 2313-2IN
HOT CAMS
$264.95If you're serious about maximizing your KX250F's engine output, a high-quality aftermarket camshaft is one of the most direct paths to measurable performance gains. The Hot Cams Stage 2 drops in without requiring expensive valve spring modifications,...09251244- SKU:
- 09251244
- Availability:
- Ships Same Business Day
- Weight:
- 0.76 LBS
- INTAKE DURATION IMPERIAL:
- 254°
- PRODUCT NAME:
- CAMSHAFT
- APPLICATION:
- INTAKE
- INTAKE LIFT METRIC:
- 10.41 MM
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- STAGE 2
- UNITS:
- EACH
$264.95 -
Hot Cams Valve Shim 10.0 x 2.35 for KTM 690 Enduro 2008 5PK1000235
HOT CAMS
$11.95Valve clearance drift is inevitable with engine wear, and running out-of-spec shims compromises both performance and longevity. The Hot Cams Valve Shim 10.0 x 2.35 gives you precision-engineered replacements to restore exact valve timing on your KTM 690...09261284- SKU:
- 09261284
- Availability:
- Ships Same Business Day
- Weight:
- 0.05 LBS
- OUTSIDE DIAMETER METRIC:
- 10.00 MM
- VALVE SHIM THICKNESS METRIC:
- 2.35 MM
- PRODUCT NAME:
- SHIM
- TYPE:
- VALVE
- UNITS:
- 5 PACK
- MATERIAL:
- STEEL
- RIDING STYLE:
- OFF-ROAD
$11.95 -
Hot Cams Valve Shim 10.00mm x 3.10mm for KTM 530 EXC-R 2008-2010 5PK1000310
HOT CAMS
$11.95Valve clearance directly impacts combustion efficiency, fuel economy, and engine longevity—and this Hot Cams shim kit gives you precise adjustment capability without guesswork. Whether you're dialing in a freshly rebuilt top-end or fine-tuning an...09261299- SKU:
- 09261299
- Availability:
- Ships Same Business Day
- Weight:
- 0.02 LBS
- OUTSIDE DIAMETER METRIC:
- 10.00 MM
- PRODUCT NAME:
- SHIM
- TYPE:
- VALVE
- UNITS:
- 5 PACK
- VALVE SHIM THICKNESS METRIC:
- 3.10 MM
- MATERIAL:
- STEEL
- RIDING STYLE:
- OFF-ROAD
$11.95 -
Hot Cams Valve Shim 10.0 x 3.15 for KTM 530 EXC-R 2008-2010 5PK1000315
HOT CAMS
$11.95Valve clearance directly impacts your KTM 530 EXC-R's combustion efficiency, fuel economy, and engine longevity. Over time, thermal cycling causes valve seats to settle, requiring shim adjustments to maintain factory specifications. This genuine Hot Cams...09261300- SKU:
- 09261300
- Availability:
- Ships Same Business Day
- Weight:
- 0.02 LBS
- TYPE:
- VALVE
- MATERIAL:
- STEEL
- RIDING STYLE:
- OFF-ROAD
- OUTSIDE DIAMETER METRIC:
- 10.00 MM
- PRODUCT NAME:
- SHIM
- UNITS:
- 5 PACK
- VALVE SHIM THICKNESS METRIC:
- 3.15 MM
$11.95
