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 specifications. The Wiseco Engine Rebuild Kit delivers...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 parts you need to restore your four-stroke to factory...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 everything needed for a full top and bottom-end...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 Rebuild Kit PWR140-102 provides everything needed for a...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 components—crankshaft, rod, bearings, and seals—all tuned for the...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 critical components—pistons, rings, bearings, seals, and...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 one package, eliminating the guesswork of sourcing...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 reliability. The Wiseco PWR213-100 kit eliminates guesswork by...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 precision-engineered intake and exhaust valves designed to...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 valve solution engineered to OEM specifications,...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 springs that restore or exceed factory performance...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 and springs engineered to handle the demands of high-RPM...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 engineered to handle aggressive riding conditions while...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 upgrading from worn factory components, this complete kit...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
$365.95 -
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 high-RPM performance, while the precision-calibrated...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 premium steel construction and precision-calibrated...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 OEM-quality intake and exhaust valves engineered to withstand...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 OEM-spec valves and springs engineered to handle the...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 kit with precision-calibrated springs engineered to...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 resists wear far longer than OEM components while...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
