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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Wiseco Engine Rebuild Kit Yamaha YZ450F 2003-2005 PWR139-100
WISECO
$969.95Your YZ450F's engine has finite service life—whether you've logged serious track hours or encountered catastrophic failure, a complete rebuild demands quality components engineered to exact OEM...09031526- SKU:
- 09031526
- Availability:
- Ships Same Business Day
- Weight:
- 13.80 LBS
$969.95Qty in Cart: 0Quantity:Price:$969.95Subtotal: -
Wiseco Engine Rebuild Kit for 2003-2004 Yamaha YZ250F PWR140-100
WISECO
$889.95A complete engine rebuild demands precision-engineered components that won't compromise your YZ250F's performance when it matters most. The Wiseco PWR140-100 kit delivers all the critical internal...09031527- SKU:
- 09031527
- Availability:
- Ships Same Business Day
- Weight:
- 11.25 LBS
$889.95Qty in Cart: 0Quantity:Price:$889.95Subtotal: -
Wiseco Engine Rebuild Kit for Yamaha YZ250F 2005-2007 PWR140-101
WISECO
$889.95Engine wear and fatigue are inevitable on the track and trail, but a complete rebuild doesn't have to mean sourcing parts from multiple suppliers. The Wiseco Engine Rebuild Kit for YZ250F delivers...09031528- SKU:
- 09031528
- Availability:
- Ships Same Business Day
- Weight:
- 11.35 LBS
$889.95Qty in Cart: 0Quantity:Price:$889.95Subtotal: -
Wiseco Engine Rebuild Kit Yamaha YZ250F 2008-2011 PWR140-102
WISECO
$988.95When your YZ250F's engine reaches the end of its service life, a quality rebuild kit is the difference between getting back on the track and dealing with catastrophic failure. The Wiseco Engine...09031529- SKU:
- 09031529
- Availability:
- Ships Same Business Day
- Weight:
- 11.30 LBS
$988.95Qty in Cart: 0Quantity:Price:$988.95Subtotal: -
Wiseco Engine Rebuild Kit for 2006 Kawasaki KX250F PWR144-101
WISECO
$932.95A top-end and bottom-end rebuild kit gives you a complete, factory-engineered solution when your KX250F demands more than patchwork repairs. The Wiseco PWR144-101 delivers OEM-quality...09031532- SKU:
- 09031532
- Availability:
- Ships Same Business Day
- Weight:
- 11.30 LBS
$932.95 -
Wiseco Engine Rebuild Kit for Kawasaki KX250F 2007-2008 PWR144-102
WISECO
$932.95When your KX250F's engine reaches the end of its service life, a complete rebuild restores it to factory specifications without the cost of replacement. The Wiseco PWR144-102 kit supplies all...09031533- SKU:
- 09031533
- Availability:
- Ships Same Business Day
- Weight:
- 11.25 LBS
$932.95 -
Wiseco Engine Rebuild Kit Honda CRF250R 2008-2009 PWR159-100
WISECO
$888.95A complete engine rebuild requires precision components that can withstand the demands of competitive riding and trail use. This Wiseco kit delivers all the critical internal components you need in...09031537- SKU:
- 09031537
- Availability:
- Ships Same Business Day
- Weight:
- 11.25 LBS
$888.95Qty in Cart: 0Quantity:Price:$888.95Subtotal: -
Wiseco Engine Rebuild Kit for KTM 125 SX 2016-2017 PWR213-100
WISECO
$884.95When your KTM 125 SX engine shows signs of wear—whether from track abuse or high-mileage riding—a complete rebuild with quality components is the only way to restore original performance and...09031672- SKU:
- 09031672
- Availability:
- Ships Same Business Day
- Weight:
- 8.75 LBS
- BORE SIZE METRIC:
- 54.00 MM
- PRODUCT NAME:
- REBUILD KIT
- TYPE:
- ENGINE
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
$884.95Qty in Cart: 0Quantity:Price:$884.95Subtotal: -
Wiseco Steel Valve Kit Honda CRF250R 2004-2007 SVKB1336
WISECO
$365.95If you're pushing your CRF250R beyond stock limits, the factory valve train becomes your first reliability bottleneck. This Wiseco steel valve kit replaces those compromised components with...09263058- SKU:
- 09263058
- Availability:
- Ships Same Business Day
- Weight:
- 1.00 LBS
- UNITS:
- KIT
- APPLICATION:
- EXHAUST
- APPLICATION:
- INTAKE
- MATERIAL:
- STEEL
- PRODUCT NAME:
- VALVE KIT
- RIDING STYLE:
- OFF-ROAD
$365.95 -
Wiseco Valve Kit for Honda CRF250R 2008-2009 SVKB1337
WISECO
$365.95If you're rebuilding or refreshing your CRF250R's top end, valve quality directly impacts combustion efficiency, engine longevity, and overall reliability. The Wiseco SVKB1337 delivers a complete...09263059- SKU:
- 09263059
- Availability:
- Ships Same Business Day
- Weight:
- 1.00 LBS
- APPLICATION:
- EXHAUST
- MATERIAL:
- STEEL
- PRODUCT NAME:
- VALVE KIT
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- APPLICATION:
- INTAKE
$365.95 -
Wiseco Valve Kit Honda CRF250R 2010-2015 SVKB1340
WISECO
$365.95The Honda CRF250R demands valve components that can handle the demands of competition and high-mileage riding. Wiseco's SVKB1340 valve kit delivers OEM-quality steel valves and precision-engineered...09263060- SKU:
- 09263060
- Availability:
- Ships Same Business Day
- Weight:
- 1.00 LBS
- MATERIAL:
- STEEL
- PRODUCT NAME:
- VALVE KIT
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- APPLICATION:
- EXHAUST
- APPLICATION:
- INTAKE
$365.95Qty in Cart: 0Quantity:Price:$365.95Subtotal: -
Wiseco Valve Kit Honda CRF450R 2009-2012 SVKB1409
WISECO
$365.95When you're rebuilding or refreshing your CRF450R's top end, valve quality directly impacts combustion efficiency, power delivery, and engine longevity. The Wiseco SVKB1409 delivers OEM-spec valves...09263063- SKU:
- 09263063
- Availability:
- Ships Same Business Day
- Weight:
- 1.00 LBS
- APPLICATION:
- INTAKE
- MATERIAL:
- STEEL
- PRODUCT NAME:
- VALVE KIT
- RIDING STYLE:
- OFF-ROAD
- APPLICATION:
- EXHAUST
- UNITS:
- KIT
$365.95Qty in Cart: 0Quantity:Price:$365.95Subtotal: -
Wiseco Valve Kit for Honda CRF450R 2013-2016 SVKB1410
WISECO
$344.95Factory valve springs fatigue under sustained high RPM operation, leading to valve float and loss of compression. The Wiseco SVKB1410 replaces worn internals with precision-matched components...09263064- SKU:
- 09263064
- Availability:
- Ships Same Business Day
- Weight:
- 1.15 LBS
- APPLICATION:
- INTAKE
- MATERIAL:
- STEEL
- PRODUCT NAME:
- VALVE KIT
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- APPLICATION:
- EXHAUST
$344.95Qty in Cart: 0Quantity:Price:$344.95Subtotal: -
Wiseco Valve Kit YZ250F 2014-2018 SVKB2414
WISECO
$365.95The Wiseco Valve Kit SVKB2414 delivers OEM-quality intake and exhaust valves engineered to handle the demands of high-performance riding. Whether you're rebuilding after a top-end refresh or...09263066- SKU:
- 09263066
- Availability:
- Ships Same Business Day
- Weight:
- 1.00 LBS
- APPLICATION:
- INTAKE
- MATERIAL:
- STEEL
- PRODUCT NAME:
- VALVE KIT
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- APPLICATION:
- EXHAUST
$365.95Qty in Cart: 0Quantity:Price:$365.95Subtotal: -
Wiseco Steel Valve Kit YZ450F 2003-2009 SVKB2424
WISECO
$428.95If you're running a YZ450F hard enough to need a top-end rebuild, OEM valves won't cut it. The Wiseco Steel Valve Kit SVKB2424 delivers the durability and thermal stability required for sustained...09263067- SKU:
- 09263067
- Availability:
- Ships Same Business Day
- Weight:
- 0.95 LBS
- APPLICATION:
- EXHAUST
- PRODUCT NAME:
- VALVE KIT
- UNITS:
- KIT
- MATERIAL:
- STEEL
- RIDING STYLE:
- OFF-ROAD
- APPLICATION:
- INTAKE
- RIDING STYLE:
- ATV
$428.95 -
Wiseco Valve Kit Yamaha YZ450F 2014-2015 SVKB2444
WISECO
$391.95Your YZ450F's valvetrain demands precision components that can handle aggressive riding conditions without compromising reliability. The Wiseco SVKB2444 valve kit delivers OEM-equivalent quality with...09263069- SKU:
- 09263069
- Availability:
- Ships Same Business Day
- Weight:
- 1.05 LBS
- APPLICATION:
- EXHAUST
- APPLICATION:
- INTAKE
- MATERIAL:
- STEEL
- PRODUCT NAME:
- VALVE KIT
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
$391.95 -
Wiseco Valve Kit Suzuki RM-Z450 2005-2006 SVKB3405
WISECO
$365.95If you're running an RM-Z450 and serious about maintaining peak engine performance, valve wear is inevitable—but premature failure doesn't have to be. The Wiseco Valve Kit SVKB3405 delivers...09263071- SKU:
- 09263071
- Availability:
- Ships Same Business Day
- Weight:
- 0.95 LBS
- UNITS:
- KIT
- APPLICATION:
- EXHAUST
- APPLICATION:
- INTAKE
- MATERIAL:
- STEEL
- PRODUCT NAME:
- VALVE KIT
- RIDING STYLE:
- OFF-ROAD
$365.95 -
Wiseco Valve Kit 2007 Suzuki RM-Z450 SVKB3407
WISECO
$344.95If you're rebuilding or refreshing your 2007 Suzuki RM-Z450's top end, valve quality directly impacts combustion efficiency, throttle response, and engine longevity. Wiseco's SVKB3407 kit delivers...09263073- SKU:
- 09263073
- Availability:
- Ships Same Business Day
- Weight:
- 0.90 LBS
- MATERIAL:
- STEEL
- PRODUCT NAME:
- VALVE KIT
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- APPLICATION:
- INTAKE
- APPLICATION:
- EXHAUST
$344.95Qty in Cart: 0Quantity:Price:$344.95Subtotal: -
Wiseco Valve Kit Suzuki RM-Z450 2008-2019 SVKB3408
WISECO
$365.95Your RM-Z450's valve train endures extreme loads with every combustion cycle—worn or marginal valves compromise power delivery and reliability. The Wiseco SVKB3408 delivers a complete OEM-grade valve...09263074- SKU:
- 09263074
- Availability:
- Ships Same Business Day
- Weight:
- 1.10 LBS
- APPLICATION:
- INTAKE
- MATERIAL:
- STEEL
- APPLICATION:
- EXHAUST
- PRODUCT NAME:
- VALVE KIT
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
$365.95 -
Wiseco Exhaust Valve for Yamaha YFM350 Grizzly 2007-2012 VES028
WISECO
$55.95The Wiseco VES028 exhaust valve is purpose-built to handle the extreme heat and friction demands of high-performance YFM350 Grizzly engines. With factory-grade CVD or CNI surface coatings, this valve...09262237- SKU:
- 09262237
- Availability:
- Ships Same Business Day
- Weight:
- 0.25 LBS
- APPLICATION:
- EXHAUST
- MATERIAL:
- STAINLESS STEEL
- UNITS:
- EACH
- PRODUCT NAME:
- VALVE
- RIDING STYLE:
- ATV
$55.95
