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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- Qty in Cart
- Quantity
- Price
- Subtotal
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Hot Cams Titanium Intake Valve for 2004-2009 Honda CRF250R 2004-2009 2012-2013 2015 Honda CRF250X 8400001-2
HOT CAMS
$105.95The intake valve is critical to your CRF's combustion efficiency—a worn or undersized valve directly impacts throttle response and peak power delivery. Hot Cams' forged titanium construction delivers the durability needed for sustained high-RPM...09262598- SKU:
- 09262598
- Availability:
- Ships Same Business Day
- Weight:
- 0.06 LBS
- MATERIAL:
- TITANIUM
- APPLICATION:
- INTAKE
- PRODUCT NAME:
- VALVE
- BASE COLOR:
- SILVER
- COLOR/FINISH:
- TITANIUM
- MATERIAL:
- NITRIDE COATED
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- EACH
$105.95 -
Hot Cams Titanium Intake Valve for Honda CRF450R 2002-2008 8400002-2
HOT CAMS
$103.95Your CRF450R's intake valve is critical to cylinder head efficiency and overall engine performance. OEM valves wear under sustained racing loads, leading to reduced airflow, compression loss, and increased maintenance cycles. The HOT CAMS Titanium Intake...09262601- SKU:
- 09262601
- Availability:
- Ships Same Business Day
- Weight:
- 0.11 LBS
- MATERIAL:
- TITANIUM
- APPLICATION:
- INTAKE
- PRODUCT NAME:
- VALVE
- COLOR/FINISH:
- TITANIUM
- MATERIAL:
- NITRIDE COATED
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- EACH
- BASE COLOR:
- SILVER
$103.95 -
Hot Cams Exhaust Valve 2004-2007 Honda CRF250R 8400001-1
HOT CAMS
$51.95The exhaust valve is one of the most thermally stressed components in your CRF250R's engine, and a worn or compromised valve directly reduces compression, throttle response, and overall reliability. HOT CAMS' forged one-piece construction withstands the...09262902- SKU:
- 09262902
- Availability:
- Ships Same Business Day
- Weight:
- 0.10 LBS
- COLOR/FINISH:
- BLACK
- LENGTH METRIC:
- 82.00 MM
- APPLICATION:
- EXHAUST
- BASE COLOR:
- BLACK
- PRODUCT NAME:
- VALVE
- STEM DIAMETER METRIC:
- 4.970 MM
- UNITS:
- EACH
- OUTSIDE DIAMETER METRIC:
- 26.00 MM
- MATERIAL:
- STEEL
- RIDING STYLE:
- OFF-ROAD
$51.95 -
Hot Cams Steel Exhaust Valve for Honda CRF250R 2008-2009 8400001-5
HOT CAMS
$51.95Your CRF250R's exhaust valve is critical to engine breathing, combustion efficiency, and overall performance. A worn or inferior valve compromises compression, increases fuel consumption, and degrades throttle response. The HOT CAMS 8400001-5 is a...09262903- SKU:
- 09262903
- Availability:
- Ships Same Business Day
- Weight:
- 0.10 LBS
- COLOR/FINISH:
- BLACK
- STEM DIAMETER METRIC:
- 4.460 MM
- APPLICATION:
- EXHAUST
- BASE COLOR:
- BLACK
- PRODUCT NAME:
- VALVE
- LENGTH METRIC:
- 82.00 MM
- MATERIAL:
- STEEL
- RIDING STYLE:
- OFF-ROAD
- OUTSIDE DIAMETER METRIC:
- 26.00 MM
- UNITS:
- EACH
$51.95 -
Hot Cams Valve Shim Kit 8.90mm x 1.72mm for KTM 250 SX-F 2005-2022 5PK890172
HOT CAMS
$11.95Valve clearance directly impacts combustion efficiency, valve longevity, and overall engine reliability on your KTM 250 SX-F. Over time, valve shims wear and require replacement to maintain optimal clearance specifications and prevent costly engine...09261349- SKU:
- 09261349
- Availability:
- Ships Same Business Day
- Weight:
- 0.01 LBS
- MATERIAL:
- STEEL
- OUTSIDE DIAMETER METRIC:
- 8.90 MM
- RIDING STYLE:
- ADVENTURE TOURING / DUAL-SPORT
- RIDING STYLE:
- ATV
- RIDING STYLE:
- OFF-ROAD
- RIDING STYLE:
- UTV
- RIDING STYLE:
- WATERCRAFT
- TYPE:
- VALVE
- VALVE SHIM THICKNESS METRIC:
- 1.72 MM
- PRODUCT NAME:
- SHIM
- RIDING STYLE:
- SNOW
- RIDING STYLE:
- STREET
- UNITS:
- 5 PACK
$11.95 -
Hot Cams Valve Shim 8.90 x 1.76 for KTM 250 SX-F 2005-2011 5PK890176
HOT CAMS
$11.95Valve clearance drift is inevitable with high-mileage or hard-running engines—and even small deviations will cost you horsepower and risk bent valves. Hot Cams valve shims give you precise, OEM-spec clearance adjustments without guesswork, keeping your...09261350- SKU:
- 09261350
- Availability:
- Ships Same Business Day
- Weight:
- 0.02 LBS
- RIDING STYLE:
- ATV
- TYPE:
- VALVE
- MATERIAL:
- STEEL
- OUTSIDE DIAMETER METRIC:
- 8.90 MM
- PRODUCT NAME:
- SHIM
- RIDING STYLE:
- SNOW
- UNITS:
- 5 PACK
- VALVE SHIM THICKNESS METRIC:
- 1.76 MM
- RIDING STYLE:
- STREET
- RIDING STYLE:
- ADVENTURE TOURING / DUAL-SPORT
- RIDING STYLE:
- OFF-ROAD
- RIDING STYLE:
- UTV
- RIDING STYLE:
- WATERCRAFT
$11.95 -
Hot Cams Valve Shim 8.90mm x 1.84mm for KTM 250 SX-F 2005-2011 5PK890184
HOT CAMS
$11.95Valve clearance directly impacts combustion efficiency, valve longevity, and engine reliability—especially in high-rev four-stroke engines like the KTM 250 SX-F. As shims wear or your build requires adjustment, having precision replacements on hand...09261352- SKU:
- 09261352
- Availability:
- Ships Same Business Day
- Weight:
- 0.02 LBS
- OUTSIDE DIAMETER METRIC:
- 8.90 MM
- RIDING STYLE:
- ATV
- TYPE:
- VALVE
- MATERIAL:
- STEEL
- RIDING STYLE:
- ADVENTURE TOURING / DUAL-SPORT
- RIDING STYLE:
- OFF-ROAD
- RIDING STYLE:
- SNOW
- PRODUCT NAME:
- SHIM
- RIDING STYLE:
- STREET
- RIDING STYLE:
- UTV
- RIDING STYLE:
- WATERCRAFT
- UNITS:
- 5 PACK
- VALVE SHIM THICKNESS METRIC:
- 1.84 MM
$11.95 -
Hot Cams Valve Shim 8.90mm x 1.88mm for KTM 250 SX-F 2005-2011 5PK890188
HOT CAMS
$11.95Valve clearance directly impacts combustion efficiency, power delivery, and engine longevity—and worn or incorrect shims compromise all three. These HOT CAMS shims maintain precise clearance specifications under high-RPM load, preventing valve float and...09261353- SKU:
- 09261353
- Availability:
- Ships Same Business Day
- Weight:
- 0.02 LBS
- OUTSIDE DIAMETER METRIC:
- 8.90 MM
- RIDING STYLE:
- ATV
- TYPE:
- VALVE
- VALVE SHIM THICKNESS METRIC:
- 1.88 MM
- RIDING STYLE:
- UTV
- MATERIAL:
- STEEL
- RIDING STYLE:
- ADVENTURE TOURING / DUAL-SPORT
- RIDING STYLE:
- OFF-ROAD
- PRODUCT NAME:
- SHIM
- RIDING STYLE:
- SNOW
- RIDING STYLE:
- STREET
- RIDING STYLE:
- WATERCRAFT
- UNITS:
- 5 PACK
$11.95 -
Hot Cams Valve Shim 8.90mm x 1.96mm for KTM 250 SX-F 2005-2011 5PK890196
HOT CAMS
$11.95Valve clearance drift is inevitable in high-revving engines—especially in aggressive riding conditions. Hot Cams Valve Shims are essential wear items that restore proper valve-to-rocker clearance, ensuring your KTM 250 SX-F maintains peak combustion...09261355- SKU:
- 09261355
- Availability:
- Ships Same Business Day
- Weight:
- 0.02 LBS
- RIDING STYLE:
- SNOW
- RIDING STYLE:
- STREET
- UNITS:
- 5 PACK
- RIDING STYLE:
- ADVENTURE TOURING / DUAL-SPORT
- RIDING STYLE:
- ATV
- PRODUCT NAME:
- SHIM
- RIDING STYLE:
- UTV
- RIDING STYLE:
- WATERCRAFT
- TYPE:
- VALVE
- VALVE SHIM THICKNESS METRIC:
- 1.96 MM
- MATERIAL:
- STEEL
- OUTSIDE DIAMETER METRIC:
- 8.90 MM
- RIDING STYLE:
- OFF-ROAD
$11.95 -
Hot Cams Valve Shim 8.90mm x 2.00mm for KTM 250 SX-F 2005-2011 5PK890200
HOT CAMS
$11.95Valve clearance directly impacts combustion efficiency, ignition timing, and overall engine longevity. These HOT CAMS shims are precision-engineered to maintain exact clearance specifications on your KTM 250 SX-F, preventing valve overlap issues and loss...09261356- SKU:
- 09261356
- Availability:
- Ships Same Business Day
- Weight:
- 0.06 LBS
- RIDING STYLE:
- SNOW
- OUTSIDE DIAMETER METRIC:
- 8.90 MM
- PRODUCT NAME:
- SHIM
- RIDING STYLE:
- UTV
- RIDING STYLE:
- WATERCRAFT
- TYPE:
- VALVE
- UNITS:
- 5 PACK
- RIDING STYLE:
- ATV
- RIDING STYLE:
- STREET
- VALVE SHIM THICKNESS METRIC:
- 2.00 MM
- MATERIAL:
- STEEL
- RIDING STYLE:
- ADVENTURE TOURING / DUAL-SPORT
- RIDING STYLE:
- OFF-ROAD
$11.95 -
Hot Cams Valve Shim 9.48mm x 1.20mm for Honda CRF450R 2002-2014 5PK948120
HOT CAMS
$10.95Valve clearance directly impacts combustion efficiency, power delivery, and engine longevity—especially in high-revving applications like the CRF450R. Hot Cams valve shims deliver the precision adjustment your engine needs to maintain optimal clearance...09261372- SKU:
- 09261372
- Availability:
- Ships Same Business Day
- Weight:
- 0.06 LBS
- MATERIAL:
- STEEL
- RIDING STYLE:
- ADVENTURE TOURING / DUAL-SPORT
- RIDING STYLE:
- OFF-ROAD
- RIDING STYLE:
- ATV
- RIDING STYLE:
- STREET
- PRODUCT NAME:
- SHIM
- RIDING STYLE:
- SNOW
- RIDING STYLE:
- UTV
- RIDING STYLE:
- WATERCRAFT
- TYPE:
- VALVE
- UNITS:
- 5 PACK
- OUTSIDE DIAMETER METRIC:
- 9.48 MM
- VALVE SHIM THICKNESS METRIC:
- 1.20 MM
$10.95 -
Hot Cams Valve Shim 9.48 x 1.40 for Honda CRF450R 2002-2023 5PK948140
HOT CAMS
$10.95Valve clearance directly impacts engine efficiency, combustion timing, and overall performance—and worn or incorrect shims compromise all three. The Hot Cams 9.48 x 1.40 shim pack gives you precision-engineered replacements to restore proper valve lash...09261376- SKU:
- 09261376
- Availability:
- Ships Same Business Day
- Weight:
- 0.05 LBS
- RIDING STYLE:
- ATV
- TYPE:
- VALVE
- MATERIAL:
- STEEL
- OUTSIDE DIAMETER METRIC:
- 9.48 MM
- RIDING STYLE:
- ADVENTURE TOURING / DUAL-SPORT
- RIDING STYLE:
- OFF-ROAD
- VALVE SHIM THICKNESS METRIC:
- 1.40 MM
- PRODUCT NAME:
- SHIM
- RIDING STYLE:
- SNOW
- RIDING STYLE:
- STREET
- RIDING STYLE:
- UTV
- RIDING STYLE:
- WATERCRAFT
- UNITS:
- 5 PACK
$10.95 -
Hot Cams Valve Shim 9.48mm x 1.45mm for Honda CRF450R 2002-2018 5PK948145
HOT CAMS
$10.95Valve clearance directly impacts combustion efficiency, noise levels, and engine longevity—and these HOT CAMS shims give you precise control over that critical tolerance. Whether you're rebuilding after a top-end refresh or fine-tuning an existing setup,...09261377- SKU:
- 09261377
- Availability:
- Ships Same Business Day
- Weight:
- 0.05 LBS
- RIDING STYLE:
- ATV
- RIDING STYLE:
- UTV
- RIDING STYLE:
- WATERCRAFT
- TYPE:
- VALVE
- MATERIAL:
- STEEL
- OUTSIDE DIAMETER METRIC:
- 9.48 MM
- RIDING STYLE:
- ADVENTURE TOURING / DUAL-SPORT
- RIDING STYLE:
- OFF-ROAD
- VALVE SHIM THICKNESS METRIC:
- 1.45 MM
- PRODUCT NAME:
- SHIM
- RIDING STYLE:
- SNOW
- RIDING STYLE:
- STREET
- UNITS:
- 5 PACK
$10.95 -
Hot Cams Valve Shim 9.48mm x 1.50mm for Honda CRF450R 2002-2023 5PK948150
HOT CAMS
$10.95Valve clearance directly impacts engine performance, combustion efficiency, and component longevity—especially critical on high-revving engines like the CRF450R. Hot Cams valve shims ensure precise clearance maintenance without compromising reliability,...09261378- SKU:
- 09261378
- 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
- RIDING STYLE:
- ADVENTURE TOURING / DUAL-SPORT
- RIDING STYLE:
- OFF-ROAD
- RIDING STYLE:
- UTV
- RIDING STYLE:
- WATERCRAFT
- VALVE SHIM THICKNESS METRIC:
- 1.50 MM
$10.95 -
Wiseco Piston Kit Kawasaki JS550 1991-1995 75.50mm Bore WK1046
WISECO
$349.95A complete piston kit rebuild is essential when your JS550 engine shows signs of wear, loss of compression, or if you're pushing higher RPMs and demand absolute reliability. Wiseco's high-silicon forged aluminum construction delivers the strength needed...WK1046- SKU:
- WK1046
- Availability:
- Ships Same Business Day
- Weight:
- 2.19 LBS
- RIDING STYLE:
- WATERCRAFT
- MODEL:
- FORGED SERIES
- SKIRT COATING:
- NON-COATED
- UNITS:
- KIT
- BORE - OVERSIZE METRIC:
- +0.50 MM
- BORE SIZE METRIC:
- 75.50 MM
- PISTON DIAMETER METRIC:
- 75.40 MM
- PRODUCT NAME:
- REBUILD KIT
- TYPE:
- TOP END
- BORE - OVERSIZE:
- +0,50 MM
- DISPLACEMENT:
- 537 CC
- ENGINE TYPE:
- 2-STROKE
- PISTON MATERIAL:
- 4032 ALUMINUM ALLOY
$349.95 -
Rekluse Clutch Cover Sherco 250 SE-R 2018-2025 RMS-0408001
REKLUSE
$229.00The stock clutch cover on your Sherco 250 SE-R leaves performance on the table. A deeper oil capacity directly translates to better clutch cooling and more consistent lever feel through intense riding sessions, while a billet aluminum construction...09401979- SKU:
- 09401979
- Availability:
- Ships Same Business Day
- Weight:
- 0.80 LBS
- RIDING STYLE:
- STREET
- PRODUCT NAME:
- COVER
- UNITS:
- EACH
- COLOR/FINISH:
- ANODIZED
- COLOR/FINISH:
- BLACK
- MATERIAL:
- BILLET ALUMINUM
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- CLUTCH
$229.00 -
Rekluse Clutch Cover Beta 350 RR 2020-2025 RMS-0402028
REKLUSE
$229.00The stock clutch cover on your Beta 350 RR is vulnerable to impact damage and thermal stress during aggressive trail riding. This Rekluse billet aluminum replacement delivers superior protection, increased oil capacity for better heat management, and the...09401943- SKU:
- 09401943
- Availability:
- Ships Same Business Day
- Weight:
- 0.96 LBS
- PRODUCT NAME:
- COVER
- UNITS:
- EACH
- COLOR/FINISH:
- ANODIZED
- COLOR/FINISH:
- BLACK
- MATERIAL:
- BILLET ALUMINUM
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- CLUTCH
- RIDING STYLE:
- STREET
$229.00 -
Rekluse Clutch Cover GasGas EC 250 2018-2019 RMS-300
REKLUSE
$279.00Off-road riding demands protection that doesn't compromise on durability or engine reliability. The Rekluse Clutch Cover for your GasGas EC 250/300 shields critical components from trail impacts while increasing oil capacity for superior lubrication...09401777- SKU:
- 09401777
- Availability:
- Ships Same Business Day
- Weight:
- 1.00 LBS
- COLOR/FINISH:
- BLACK
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- CLUTCH
- RIDING STYLE:
- STREET
- COLOR/FINISH:
- ANODIZED
- MATERIAL:
- BILLET ALUMINUM
- PRODUCT NAME:
- COVER
- UNITS:
- EACH
$279.00 -
Rekluse Clutch Cover GasGas EC 200 2000-2011 RMS-302
REKLUSE
$229.00Trail damage to your stock clutch cover risks oil leaks, reduced lubrication, and costly engine repairs. The Rekluse billet aluminum cover provides superior impact resistance while increasing oil capacity for better thermal management and engine...09401778- SKU:
- 09401778
- Availability:
- Ships Same Business Day
- Weight:
- 0.95 LBS
- COLOR/FINISH:
- ANODIZED
- COLOR/FINISH:
- BLACK
- MATERIAL:
- BILLET ALUMINUM
- PRODUCT NAME:
- COVER
- RIDING STYLE:
- OFF-ROAD
- RIDING STYLE:
- STREET
- TYPE:
- CLUTCH
- UNITS:
- EACH
$229.00 -
Rekluse Clutch Cover KTM 65 SX 2009-2025 RMS-387
REKLUSE
$229.00The stock clutch cover on your KTM 65 SX is vulnerable to damage from rocks, roots, and impacts that are inevitable in aggressive riding. The Rekluse RMS-387 clutch cover replaces that weak point with billet aluminum construction and a deeper design that...09401818- SKU:
- 09401818
- Availability:
- Ships Same Business Day
- Weight:
- 0.75 LBS
- TYPE:
- CLUTCH
- COLOR/FINISH:
- ANODIZED
- COLOR/FINISH:
- BLACK
- MATERIAL:
- BILLET ALUMINUM
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- EACH
- PRODUCT NAME:
- COVER
$229.00
