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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- Price
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REKLUSE Clutch Cover - Gas Gas/Husqvarna/KTM RMS-0413065
REKLUSE
$229.00Stock clutch covers fail under the rigors of aggressive riding—impacts with rocks, logs, and boot contact compromise both protection and oil containment. The REKLUSE Clutch Cover replaces this...09402216- SKU:
- 09402216
- Availability:
- Ships Same Business Day
- Weight:
- 0.83 LBS
$229.00 -
MOOSE RACING Intake Valve M40-41650
MOOSE RACING
$196.95Stock intake valves are often the limiting factor in engine breathing efficiency—premature wear and suboptimal flow characteristics directly impact power output and reliability. The MOOSE RACING...09263371- SKU:
- 09263371
- Availability:
- Ships Same Business Day
- Weight:
- 0.46 LBS
$196.95 -
MOOSE RACING Valve Seal Kit M30-34020
MOOSE RACING
$15.95Worn or degraded valve seals cause oil consumption, compression loss, and poor combustion efficiency—problems that compound quickly under racing or high-load conditions. The MOOSE RACING M30-34020...09263375- SKU:
- 09263375
- Availability:
- Ships Same Business Day
- Weight:
- 0.06 LBS
$15.95 -
MOOSE RACING Valve Seal Kit M40-41680
MOOSE RACING
$15.95Engine valve seals naturally degrade under heat and combustion pressures, leading to oil leakage, blue smoke, and reduced compression. The MOOSE RACING Valve Seal Kit M40-41680 replaces worn seals...09263376- SKU:
- 09263376
- Availability:
- Ships Same Business Day
- Weight:
- 0.06 LBS
$15.95 -
On Sale
Wossner Crankshaft Assembly for KTM SX125 2016-2022 Husqvarna TC125 2016-2022 GasGas MC125 2021-2022 CS2070
WOSSNER
MSRP: $342.00Now: $324.90Was: $342.00A worn or damaged crankshaft assembly compromises power transfer, throttle response, and engine longevity—particularly critical in 2-stroke competition machines where precision clearances determine...09210879- SKU:
- 09210879
- Availability:
- Ships Same Business Day
- Weight:
- 6.25 LBS
MSRP: $342.00Now: $324.90Was: $342.00 -
On Sale
WOSSNER Crankshaft Assembly - Husaberg | Husqvarna | KTM CS2012
WOSSNER
MSRP: $342.00Now: $324.90Was: $342.00A worn or damaged crankshaft assembly compromises engine reliability and performance—especially critical in high-demand riding conditions where precision matters. The WOSSNER CS2012 delivers...09210880- SKU:
- 09210880
- Availability:
- Ships Same Business Day
- Weight:
- 6.95 LBS
MSRP: $342.00Now: $324.90Was: $342.00 -
On Sale
Wossner Crankshaft Assembly for Honda CRF250R 2010-2017 CS4001
WOSSNER
MSRP: $404.00Now: $383.80Was: $404.00The crankshaft is the heart of your engine—when it wears or fails, your CRF250R's performance suffers immediately. This Wossner assembly restores full power delivery and reliability with OEM-quality...09210881- SKU:
- 09210881
- Availability:
- Ships Same Business Day
- Weight:
- 8.49 LBS
MSRP: $404.00Now: $383.80Was: $404.00 -
On Sale
Wossner Crankshaft Assembly Kawasaki KX85 2006-2021 KX100 2006-2021 CS2005
WOSSNER
MSRP: $282.00Now: $267.90Was: $282.00A worn or damaged crankshaft assembly directly compromises your KX85 or KX100's reliability and power delivery. This Wossner complete assembly restores your engine to OEM-spec performance with...09210907- SKU:
- 09210907
- Availability:
- Ships Same Business Day
- Weight:
- 4.14 LBS
MSRP: $282.00Now: $267.90Was: $282.00 -
On Sale
Wossner Crankshaft Assembly Honda CR125R 1990-2007 CS2009
WOSSNER
MSRP: $342.00Now: $324.90Was: $342.00The crankshaft is the heart of your engine—when it fails or wears, your CR125R loses power, reliability, and precision. This Wossner assembly restores full performance with a CNC-precision...09210909- SKU:
- 09210909
- Availability:
- Ships Same Business Day
- Weight:
- 6.06 LBS
MSRP: $342.00Now: $324.90Was: $342.00 -
On Sale
Wossner Crankshaft Assembly Yamaha YZ250 2003-2024 CS2028
WOSSNER
MSRP: $482.95Now: $458.80Was: $482.95A worn or damaged crankshaft directly compromises your YZ250's power delivery, throttle response, and engine reliability. The Wossner CS2028 restores full performance potential with...09210912- SKU:
- 09210912
- Availability:
- Ships Same Business Day
- Weight:
- 9.00 LBS
MSRP: $482.95Now: $458.80Was: $482.95 -
On Sale
Wossner Crankshaft Assembly Gas Gas MC 65 2021-2022 CS2055
WOSSNER
MSRP: $282.00Now: $267.90Was: $282.00A worn or damaged crankshaft directly compromises engine efficiency, throttle response, and overall reliability—especially in high-demand 2-stroke applications. The Wossner CS2055 restores your Gas...09210913- SKU:
- 09210913
- Availability:
- Ships Same Business Day
- Weight:
- 3.97 LBS
MSRP: $282.00Now: $267.90Was: $282.00 -
On Sale
Wossner Crankshaft Assembly Yamaha YZ65 2018-2025 CS2071
WOSSNER
MSRP: $262.00Now: $248.90Was: $262.00A worn or damaged crankshaft directly compromises engine reliability and performance—especially critical on a high-revving YZ65 where precise reciprocating motion is essential. The Wossner CS2071...09210916- SKU:
- 09210916
- Availability:
- Ships Same Business Day
- Weight:
- 3.61 LBS
MSRP: $262.00Now: $248.90Was: $262.00 -
On Sale
Wossner Crankshaft Assembly Yamaha YZ250F 2014-2021 CS4072
WOSSNER
MSRP: $404.00Now: $383.80Was: $404.00The CS4072 crankshaft assembly is a precision-engineered replacement that restores your YZ250F's bottom-end reliability and maintains factory performance specifications. Whether you're rebuilding...09210921- SKU:
- 09210921
- Availability:
- Ships Same Business Day
- Weight:
- 7.00 LBS
MSRP: $404.00Now: $383.80Was: $404.00 -
On Sale
VINTCO Top End Piston Kit KTH01-00
VINTCO
MSRP: $183.95Now: $171.07Was: $183.95A worn top end compromises both power output and engine reliability—this kit gives you everything needed for a complete rebuild in one box. Whether you're restoring a tired engine or upgrading after...09106407- SKU:
- 09106407
- Availability:
- Ships Same Business Day
- Weight:
- 1.01 LBS
MSRP: $183.95Now: $171.07Was: $183.95 -
On Sale
VINTCO Top End Piston Kit KTH01-1.0
VINTCO
MSRP: $198.85Now: $184.93Was: $198.85A complete top-end rebuild requires precision-engineered components that work in concert—and this kit delivers all the critical parts in one package. Whether you're restoring lost compression,...09106409- SKU:
- 09106409
- Availability:
- Ships Same Business Day
- Weight:
- 1.06 LBS
MSRP: $198.85Now: $184.93Was: $198.85 -
On Sale
VINTCO Top End Piston Kit KTH01-1.5
VINTCO
MSRP: $198.85Now: $184.93Was: $198.85A top-end rebuild demands precision components and complete gasket coverage—this kit eliminates sourcing parts piecemeal and ensures your engine seals properly at every critical junction. Whether...09106410- SKU:
- 09106410
- Availability:
- Ships Same Business Day
- Weight:
- 1.01 LBS
MSRP: $198.85Now: $184.93Was: $198.85 -
On Sale
VINTCO Top End Piston Kit KTH02-00
VINTCO
MSRP: $188.85Now: $175.63Was: $188.85A complete top-end rebuild requires precision components that work in harmony—and this kit delivers all the critical parts in one box. Whether you're refreshing a worn engine or building a...09106411- SKU:
- 09106411
- Availability:
- Ships Same Business Day
- Weight:
- 0.92 LBS
MSRP: $188.85Now: $175.63Was: $188.85 -
On Sale
VINTCO Top End Piston Kit KTH02-0.5
VINTCO
MSRP: $188.85Now: $175.63Was: $188.85A worn or damaged top end is a reliability killer—and rebuilding with OEM-equivalent components ensures your engine performs at its peak without compromise. The VINTCO KTH02-0.5 gives you everything...09106412- SKU:
- 09106412
- Availability:
- Ships Same Business Day
- Weight:
- 1.01 LBS
MSRP: $188.85Now: $175.63Was: $188.85 -
On Sale
VINTCO Top End Piston Kit KTH02-1.0
VINTCO
MSRP: $188.85Now: $175.63Was: $188.85A top-end rebuild demands precision components that restore compression, sealing, and reliability. The VINTCO KTH02-1.0 delivers a complete piston assembly with matched rings, bearings, and...09106413- SKU:
- 09106413
- Availability:
- Ships Same Business Day
- Weight:
- 1.01 LBS
MSRP: $188.85Now: $175.63Was: $188.85 -
On Sale
VINTCO Top End Piston Kit KTH03-0.5
VINTCO
MSRP: $195.85Now: $182.14Was: $195.85A worn or damaged top end doesn't just cost you performance—it costs you reliability on the track or trail. The VINTCO Top End Piston Kit KTH03-0.5 gives you a complete solution with OEM-quality...09106416- SKU:
- 09106416
- Availability:
- Ships Same Business Day
- Weight:
- 1.01 LBS
MSRP: $195.85Now: $182.14Was: $195.85
