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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XCELDYNE X2 Titanium Valve - Intake X2TIVM43008
XCELDYNE
$110.19Off-road performance demands valve integrity that won't compromise under extreme conditions. The XCELDYNE X2 Titanium Valve delivers the flow characteristics and material durability required to extract maximum power while maintaining reliability across...09262898- SKU:
- 09262898
- Availability:
- Ships Same Business Day
- Weight:
- 0.15 LBS
- PRODUCT NAME:
- VALVE
- MATERIAL:
- TITANIUM
- APPLICATION:
- INTAKE
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
$110.19Qty in Cart: 0Quantity:Price:$110.19Subtotal: -
Hinson Racing Clutch Cover Honda CRF450X 2005-2017 C154X
HINSON RACING
$159.99Stock clutch covers on the CRF450X aren't designed for sustained high-performance riding—they trap heat and compromise durability when you're pushing hard on the track or trail. The Hinson Racing Clutch Cover eliminates this weakness with race-proven...09400738- SKU:
- 09400738
- Availability:
- Ships Same Business Day
- Weight:
- 0.72 LBS
- MODEL:
- BILLETPROOF
- COLOR/FINISH:
- BLACK
- MATERIAL:
- T-6 ALUMINUM
- PRODUCT NAME:
- COVER
- UNITS:
- EACH
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- CLUTCH
$159.99 -
Hinson Racing Clutch Cover 2002-2016 Honda CRF450R C389
HINSON RACING
$159.99Factory clutch covers weren't engineered for sustained high-RPM racing environments—they overheat under load and compromise engagement consistency. The Hinson Racing Clutch Cover eliminates thermal buildup through strategic fin design and superior...09400818- SKU:
- 09400818
- Availability:
- Ships Same Business Day
- Weight:
- 0.76 LBS
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- CLUTCH
- COLOR/FINISH:
- BLACK
- MATERIAL:
- T-6 ALUMINUM
- PRODUCT NAME:
- COVER
- UNITS:
- EACH
- MODEL:
- BILLETPROOF
$159.99 -
Hinson Racing Clutch Cover for Yamaha YZ450F 2010-2022 C416
HINSON RACING
$159.99The stock clutch cover on your YZ450F can't handle sustained high-RPM heat cycles without thermal degradation—especially in closed-course racing or extended trail sessions. Hinson's C416 clutch cover dissipates heat more effectively than OEM designs,...09400982- SKU:
- 09400982
- Availability:
- Ships Same Business Day
- Weight:
- 0.86 LBS
- COLOR/FINISH:
- BLACK
- MATERIAL:
- T-6 ALUMINUM
- PRODUCT NAME:
- COVER
- UNITS:
- EACH
- MODEL:
- BILLETPROOF
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- CLUTCH
$159.99 -
Hinson Racing Clutch Cover Kawasaki KX85 2001-2025 C068
HINSON RACING
$159.99Thermal management is critical when you're pushing a KX85 to its limits on the track. The Hinson Racing Clutch Cover dissipates heat more effectively than stock covers, keeping your clutch engagement consistent lap after lap. Built with racing-grade...09401035- SKU:
- 09401035
- Availability:
- Ships Same Business Day
- Weight:
- 0.80 LBS
- COLOR/FINISH:
- BLACK
- MATERIAL:
- T-6 ALUMINUM
- PRODUCT NAME:
- COVER
- UNITS:
- EACH
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- CLUTCH
- MODEL:
- BILLETPROOF
$159.99 -
Hinson Racing Clutch Cover for Yamaha YFZ450 2004-2013 C196
HINSON RACING
$159.99Stock clutch covers aren't engineered for sustained high-RPM racing conditions—they'll overheat and cause engagement inconsistencies when you need reliability most. The Hinson Racing Clutch Cover replaces that weakness with superior thermal management...C196- SKU:
- C196
- Availability:
- Ships Same Business Day
- Weight:
- 1.00 LBS
- MODEL:
- BILLETPROOF
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- CLUTCH
- PRODUCT NAME:
- COVER
- UNITS:
- EACH
- COLOR/FINISH:
- BLACK
- MATERIAL:
- T-6 ALUMINUM
$159.99 -
Hinson Racing Clutch Cover for Suzuki RM250 2002-2008 C046
HINSON RACING
$159.99Heat buildup is the silent killer of clutch performance, especially during sustained high-RPM riding or racing conditions. The Hinson Racing Clutch Cover for your RM250 combats this with superior thermal management and materials that outperform stock...C046X- SKU:
- C046X
- Availability:
- Ships Same Business Day
- Weight:
- 0.80 LBS
- MODEL:
- BILLETPROOF
- RIDING STYLE:
- OFF-ROAD
- COLOR/FINISH:
- BLACK
- MATERIAL:
- T-6 ALUMINUM
- TYPE:
- CLUTCH
- PRODUCT NAME:
- COVER
- UNITS:
- EACH
$159.99 -
Rekluse Clutch Cover KTM 65 SX 2024 RMS-0413065
REKLUSE
$229.00Stock clutch covers are vulnerable to trail damage and inadequate cooling under sustained riding. The Rekluse clutch cover upgrades your KTM 65 SX with billet aluminum construction and increased oil capacity, delivering better thermal management and...09401821- SKU:
- 09401821
- Availability:
- Ships Same Business Day
- Weight:
- 0.90 LBS
- COLOR/FINISH:
- ANODIZED
- MATERIAL:
- BILLET ALUMINUM
- PRODUCT NAME:
- COVER
- TYPE:
- CLUTCH
- COLOR/FINISH:
- BLACK
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- EACH
- RIDING STYLE:
- STREET
$229.00 -
Rekluse Clutch Cover Honda CRF450R 2017-2025 RMS-409
REKLUSE
$189.00The stock CRF450R clutch cover was never designed to handle extended trail riding or high-performance use—it limits oil capacity and leaves your engine running hotter than necessary. The Rekluse billet aluminum cover increases oil volume for superior...09401824- SKU:
- 09401824
- Availability:
- Ships Same Business Day
- Weight:
- 1.05 LBS
- PRODUCT NAME:
- COVER
- UNITS:
- EACH
- COLOR/FINISH:
- ANODIZED
- COLOR/FINISH:
- BLACK
- MATERIAL:
- BILLET ALUMINUM
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- CLUTCH
$189.00 -
Rekluse Clutch Cover for Honda CRF250R 2010-2017 RMS-416
REKLUSE
$189.00The stock clutch cover on your CRF250R is vulnerable to trail debris—rocks, logs, and impacts that compromise both protection and cooling. Rekluse's billet aluminum cover increases oil capacity for better thermal management while providing substantial...09401827- SKU:
- 09401827
- Availability:
- Ships Same Business Day
- Weight:
- 1.00 LBS
- PRODUCT NAME:
- COVER
- UNITS:
- EACH
- TYPE:
- CLUTCH
- COLOR/FINISH:
- ANODIZED
- COLOR/FINISH:
- BLACK
- MATERIAL:
- BILLET ALUMINUM
- RIDING STYLE:
- OFF-ROAD
$189.00Qty in Cart: 0Quantity:Price:$189.00Subtotal: -
Rekluse Clutch Cover Kawasaki KX450F 2016-2018 RMS-444
REKLUSE
$179.00The stock clutch cover on your KX450F limits oil capacity and leaves your drivetrain vulnerable to trail impacts. The Rekluse RMS-444 replaces that weakness with a billet aluminum design that holds more oil for superior cooling and lubrication, while its...09401829- SKU:
- 09401829
- Availability:
- Ships Same Business Day
- Weight:
- 0.96 LBS
- COLOR/FINISH:
- BLACK
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- EACH
- TYPE:
- CLUTCH
- COLOR/FINISH:
- ANODIZED
- MATERIAL:
- BILLET ALUMINUM
- PRODUCT NAME:
- COVER
$179.00 -
REKLUSE Clutch Cover Kawasaki KX450 2021 RMS-445
REKLUSE
$229.00Off-road riding demands clutch protection that can handle repeated impacts without compromising lubrication or performance. The REKLUSE Clutch Cover for your KX450 delivers the durability you need with a robust billet aluminum construction and increased...09401830- SKU:
- 09401830
- Availability:
- Ships Same Business Day
- Weight:
- 0.95 LBS
- RIDING STYLE:
- STREET
- PRODUCT NAME:
- COVER
- RIDING STYLE:
- ATV
- UNITS:
- EACH
- COLOR/FINISH:
- ANODIZED
- COLOR/FINISH:
- BLACK
- MATERIAL:
- BILLET ALUMINUM
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- CLUTCH
$229.00 -
Rekluse Clutch Cover for Suzuki RM-Z450 2008-2025 RMS-464
REKLUSE
$229.00Stock clutch covers are vulnerable to trail damage and limited oil capacity—a liability when you're pushing hard on technical terrain. The Rekluse RMS-464 replaces that weakness with a billet aluminum cover engineered to absorb impacts while maintaining...09401831- SKU:
- 09401831
- Availability:
- Ships Same Business Day
- Weight:
- 1.00 LBS
- TYPE:
- CLUTCH
- COLOR/FINISH:
- BLACK
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- EACH
- COLOR/FINISH:
- ANODIZED
- MATERIAL:
- BILLET ALUMINUM
- PRODUCT NAME:
- COVER
$229.00 -
Rekluse Clutch Cover Yamaha YZ250 1999-2025 RMS-470
REKLUSE
$229.00The stock YZ250 clutch cover leaves your bike vulnerable to trail damage and thermal stress. Rekluse's billet aluminum replacement fortifies your engine case with impact-resistant protection while increasing oil capacity for better cooling during...09401833- SKU:
- 09401833
- Availability:
- Ships Same Business Day
- Weight:
- 0.95 LBS
- 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 GasGas EC 450F 2012-2015 Yamaha WR450F 2003-2015 YFZ450R 2009-2020 YZ450F 2005-2009 RMS-473
REKLUSE
$189.00The stock clutch cover on your Gas Gas or Yamaha isn't designed to handle sustained high-performance riding—especially when you're pushing hard on technical terrain. This Rekluse billet aluminum cover increases oil capacity for superior cooling and...09401835- SKU:
- 09401835
- Availability:
- Ships Same Business Day
- Weight:
- 1.05 LBS
- COLOR/FINISH:
- BLACK
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- CLUTCH
- PRODUCT NAME:
- COVER
- RIDING STYLE:
- STREET
- COLOR/FINISH:
- ANODIZED
- MATERIAL:
- BILLET ALUMINUM
- RIDING STYLE:
- ATV
- UNITS:
- EACH
$189.00Qty in Cart: 0Quantity:Price:$189.00Subtotal: -
Rekluse Clutch Cover Yamaha YZ450F 2010-2021 WR450F 2016-2021 YZ450FX 2016-2021 RMS-476
REKLUSE
$229.00If you're running a YZ450F, WR450F, or YZ450FX hard, your clutch cover needs to handle sustained heat, pressure, and trail abuse without compromising engine lubrication. The Rekluse clutch cover increases oil capacity beyond OEM specs, ensuring...09401836- SKU:
- 09401836
- Availability:
- Ships Same Business Day
- Weight:
- 0.95 LBS
- RIDING STYLE:
- STREET
- COLOR/FINISH:
- BLACK
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- EACH
- TYPE:
- CLUTCH
- COLOR/FINISH:
- ANODIZED
- MATERIAL:
- BILLET ALUMINUM
- PRODUCT NAME:
- COVER
$229.00 -
Rekluse Clutch Cover for Yamaha YZ250F 2015-2019 WR250F 2015-2019 RMS-478
REKLUSE
$229.00The stock clutch cover on your YZ/WR250F leaves your engine vulnerable to rock strikes and debris during aggressive trail and track riding. Rekluse's billet aluminum cover replaces that weakness with reinforced protection while simultaneously increasing...09401837- SKU:
- 09401837
- Availability:
- Ships Same Business Day
- Weight:
- 0.85 LBS
- TYPE:
- CLUTCH
- COLOR/FINISH:
- ANODIZED
- COLOR/FINISH:
- BLACK
- MATERIAL:
- BILLET ALUMINUM
- RIDING STYLE:
- OFF-ROAD
- PRODUCT NAME:
- COVER
- UNITS:
- EACH
$229.00Qty in Cart: 0Quantity:Price:$229.00Subtotal: -
Rekluse Clutch Cover Kawasaki KX250 2021-2024 RMS-0404140
REKLUSE
$229.00The stock KX250 clutch cover is vulnerable to impact damage and thermal stress during aggressive riding. Rekluse's billet aluminum cover replaces the OEM unit with a reinforced design that withstands rock strikes and boot catches while delivering greater...09401998- SKU:
- 09401998
- Availability:
- Ships Same Business Day
- Weight:
- 0.81 LBS
- COLOR/FINISH:
- ANODIZED
- COLOR/FINISH:
- BLACK
- MATERIAL:
- BILLET ALUMINUM
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- CLUTCH
- PRODUCT NAME:
- COVER
- UNITS:
- EACH
$229.00 -
Rekluse Clutch Cover Kawasaki KX450F 2021-2023 RMS-0404047
REKLUSE
$229.00The stock clutch cover on your KX450F is a vulnerability waiting to happen—one solid rock strike can compromise your oil seal and leave you stranded. The Rekluse Clutch Cover replaces that weak point with billet aluminum engineering that handles impacts...09401999- SKU:
- 09401999
- Availability:
- Ships Same Business Day
- Weight:
- 1.01 LBS
- COLOR/FINISH:
- BLACK
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- CLUTCH
- PRODUCT NAME:
- COVER
- COLOR/FINISH:
- ANODIZED
- MATERIAL:
- BILLET ALUMINUM
- UNITS:
- EACH
$229.00Qty in Cart: 0Quantity:Price:$229.00Subtotal: -
VERTEX Piston Kit - High Compression 24112B
VERTEX
$327.95High-compression pistons are essential for maximizing power output and fuel efficiency in performance engines, but only if they're built to withstand extreme combustion pressures without detonation or failure. The VERTEX Piston Kit 24112B combines...09104114- SKU:
- 09104114
- Availability:
- Ships Same Business Day
- Weight:
- 1.00 LBS
- DISPLACEMENT:
- 450 CC
- RIDING STYLE:
- STREET
- PISTON DIAMETER METRIC:
- 94.96 MM
- PISTON MATERIAL:
- FORGED 2618 ALUMINUM
- PRODUCT NAME:
- PISTON KIT
- COMPRESSION RATIO IMPERIAL:
- 13.6:1
- CYLINDER DIAMETER METRIC:
- 95.00 MM
- RIDING STYLE:
- OFF-ROAD
- STYLE:
- FORGED HIGH COMPRESSION
- UNITS:
- KIT
- ENGINE TYPE:
- 4-STROKE
- SKIRT COATING:
- MOLYBDENUM DISULPHITE
$327.95Qty in Cart: 0Quantity:Price:$327.95Subtotal:
