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...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...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
$159.99Qty in Cart: 0Quantity:Price:$159.99Subtotal: -
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...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...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...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...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...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...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...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...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...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...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...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...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...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...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...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...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...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...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:
