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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- Qty in Cart
- Quantity
- Price
- Subtotal
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On Sale
Pro Circuit Stainless Steel Power Valve for Kawasaki KX85 2002-2013 PVK01085
PRO CIRCUIT
MSRP: $229.95Now: $206.96Was: $229.95If you're running a KX85 and want measurable gains in low-end acceleration without sacrificing top-end power, a quality power valve upgrade is one of the highest-ROI modifications available. The Pro...09310477- SKU:
- 09310477
- Availability:
- Ships Same Business Day
- Weight:
- 0.45 LBS
- MATERIAL:
- STAINLESS STEEL
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- EACH
- PRODUCT NAME:
- POWER VALVE
MSRP: $229.95Now: $206.96Was: $229.95Qty in Cart: 0Quantity:Price:MSRP: $229.95Now: $206.96Was: $229.95Subtotal: -
HOT RODS Bottom End Kit - OE Crankshaft Replacement - Polaris HR00119
HOT RODS
$1,671.55A bottom-end rebuild demands precision components that won't compromise engine reliability or performance. This HOT RODS kit eliminates the guesswork by bundling OE-spec crankshaft replacement parts...09210898- SKU:
- 09210898
- Availability:
- Ships Same Business Day
- Weight:
- 24.35 LBS
$1,671.55 -
MOOSE OFFROAD Oil Filter - Kawasaki/Suzuki DT-09-41
MOOSE OFFROAD
$11.95Keep your Kawasaki or Suzuki engine running clean with a filter engineered to handle the demands of serious riding. This MOOSE OFFROAD oil filter delivers reliable protection through every ride,...07120223- SKU:
- 07120223
- Availability:
- Ships Same Business Day
- Weight:
- 0.12 LBS
$11.95Qty in Cart: 0Quantity:Price:$11.95Subtotal: -
MOOSE OFFROAD Motor Gasket Kit with Oil Seal - Honda 811261MSE
MOOSE OFFROAD
$110.53A failing gasket or oil seal will compromise engine integrity and lead to costly leaks, performance loss, and potential catastrophic failure. This MOOSE OFFROAD Motor Gasket Kit delivers...M811261- SKU:
- M811261
- Availability:
- Ships Same Business Day
- Weight:
- 0.30 LBS
$110.53 -
MOOSE OFFROAD Oil Seal Set - Suzuki 822309MSE
MOOSE OFFROAD
$23.29A complete engine and transmission rebuild demands precision sealing—any leak compromises performance and longevity. This MOOSE OFFROAD Oil Seal Set eliminates guesswork by consolidating all...09351185- SKU:
- 09351185
- Availability:
- Ships Same Business Day
- Weight:
- 0.02 LBS
$23.29Qty in Cart: 0Quantity:Price:$23.29Subtotal: -
MOOSE OFFROAD Top End Gasket Set 8100033MSE
MOOSE OFFROAD
$52.94A top-end gasket failure doesn't just leak—it compromises combustion integrity and puts your engine rebuild at risk. This complete MOOSE OFFROAD gasket set eliminates the guesswork of sourcing...09346890- SKU:
- 09346890
- Availability:
- Ships Same Business Day
- Weight:
- 0.07 LBS
$52.94 -
MOOSE OFFROAD Top End Gasket Set - Honda 8100029MSE
MOOSE OFFROAD
$27.22A complete top-end rebuild demands precision gaskets and seals that won't fail under heat and compression cycles. This MOOSE OFFROAD gasket set gives you everything needed for a thorough engine and...09346914- SKU:
- 09346914
- Availability:
- Ships Same Business Day
- Weight:
- 0.17 LBS
$27.22Qty in Cart: 0Quantity:Price:$27.22Subtotal: -
MOOSE OFFROAD Gasket Set with Seals - Suzuki 8110045MSE
MOOSE OFFROAD
$77.00A complete engine and transmission rebuild demands precision sealing at every junction—any compromise risks oil leakage, pressure loss, and catastrophic failure. This MOOSE OFFROAD gasket set...09346975- SKU:
- 09346975
- Availability:
- Ships Same Business Day
- Weight:
- 0.21 LBS
$77.00Qty in Cart: 0Quantity:Price:$77.00Subtotal: -
MOOSE OFFROAD Ignition Cover Gasket - Suzuki 816817MSE
MOOSE OFFROAD
$13.39A failing ignition cover gasket leads to oil seepage, potential engine contamination, and premature wear on internal components. Whether you're replacing a clutch or addressing a persistent leak,...09346976- SKU:
- 09346976
- Availability:
- Ships Same Business Day
- Weight:
- 0.02 LBS
$13.39 -
PROX Top End Gasket Set - Kawasaki 35.4429
PROX
$59.95A top-end rebuild demands gaskets that seal reliably under extreme combustion pressures and temperature fluctuations—anything less risks oil leaks, compression loss, and catastrophic engine failure...09347140- SKU:
- 09347140
- Availability:
- Ships Same Business Day
- Weight:
- 0.16 LBS
$59.95Qty in Cart: 0Quantity:Price:$59.95Subtotal: -
PROX Top End Gasket Set - Sherco 35.7334
PROX
$54.95A top-end rebuild demands gasket integrity—any leak or failure compromises combustion efficiency and reliability. The PROX 35.7334 gasket set delivers precision-engineered sealing surfaces that...09347152- SKU:
- 09347152
- Availability:
- Ships Same Business Day
- Weight:
- 0.16 LBS
$54.95Qty in Cart: 0Quantity:Price:$54.95Subtotal: -
PROX Gasket Kit - Complete - Yamaha 34.2221
PROX
$74.95A complete gasket kit is essential for any top-end rebuild or full engine overhaul—it ensures proper sealing across all critical engine surfaces and prevents oil leaks, compression loss, and...09345547- SKU:
- 09345547
- Availability:
- Ships Same Business Day
- Weight:
- 0.10 LBS
$74.95Qty in Cart: 0Quantity:Price:$74.95Subtotal: -
VERTEX Piston Kit - 76.95 mm - Kawasaki KX250F 24165A
VERTEX
$124.95Your KX250F's engine demands a piston that can handle the heat of competitive riding while maintaining the reliability you need for consistent performance. The VERTEX 76.95 mm Piston Kit delivers...09104669- SKU:
- 09104669
- Availability:
- Ships Same Business Day
- Weight:
- 0.45 LBS
$124.95Qty in Cart: 0Quantity:Price:$124.95Subtotal: -
On Sale
Wiseco Wrist Pin for Honda CRF125F 2014-2021 S538
WISECO
MSRP: $22.99Now: $20.00Was: $22.99The wrist pin is a critical load-bearing component that directly transfers combustion forces from the piston to the connecting rod. A failing or worn wrist pin compromises engine reliability, reduces...S538- SKU:
- S538
- Availability:
- Ships Same Business Day
- Weight:
- 0.04 LBS
MSRP: $22.99Now: $20.00Was: $22.99Qty in Cart: 0Quantity:Price:MSRP: $22.99Now: $20.00Was: $22.99Subtotal: -
On Sale
Wiseco Piston Kit 95.00 mm Yamaha YZ450F 2006-2009 4694M09500
WISECO
MSRP: $269.95Now: $229.00Was: $269.95If you're rebuilding your YZ450F or pushing higher RPMs on the track, a worn or damaged piston directly kills power and reliability. This Wiseco forged piston kit restores compression, improves...09102919- SKU:
- 09102919
- Availability:
- Ships Same Business Day
- Weight:
- 0.70 LBS
MSRP: $269.95Now: $229.00Was: $269.95Qty in Cart: 0Quantity:Price:MSRP: $269.95Now: $229.00Was: $269.95Subtotal: -
On Sale
Wiseco Engine Rebuild Kit 66.40mm Bore Yamaha YZ250 2003-2020 PWR134-100
WISECO
MSRP: $710.95Now: $557.00Was: $710.95A worn or damaged YZ250 engine demands a complete rebuild to restore competitive performance and reliability. This Wiseco kit eliminates the guesswork by bundling OEM-specification components in one...09031519- SKU:
- 09031519
- Availability:
- Ships Same Business Day
- Weight:
- 13.30 LBS
MSRP: $710.95Now: $557.00Was: $710.95 -
WORKS CONNECTION Radiator Drain Plug - Black - Honda/Kawasaki 24-632
WORKS CONNECTION
$23.95Stock plastic radiator drain plugs fail when you need them most—corroded, stripped, or cracked mid-season. The WORKS CONNECTION billet aluminum drain plug eliminates this weak point with a...09500984- SKU:
- 09500984
- Availability:
- Ships Same Business Day
- Weight:
- 0.11 LBS
$23.95Qty in Cart: 0Quantity:Price:$23.95Subtotal: -
WORKS CONNECTION Radiator Drain Plug - Green - Honda/Kawasaki 24-633
WORKS CONNECTION
$23.95Stock plastic radiator drain plugs fail when you need them most—corroding, cracking, or stripping threads under thermal stress. The WORKS CONNECTION billet aluminum drain plug eliminates this weak...09500985- SKU:
- 09500985
- Availability:
- Ships Same Business Day
- Weight:
- 0.11 LBS
$23.95Qty in Cart: 0Quantity:Price:$23.95Subtotal: -
On Sale
Wossner 90.00mm Piston Ring Set for 4-Stroke Engines 900XSY-3
WOSSNER
MSRP: $38.95Now: $37.00Was: $38.95Piston rings are the critical seal between your piston and cylinder wall—without proper sealing, you lose compression, power, and efficiency. This Wossner ring set restores that seal to OEM...09120683- SKU:
- 09120683
- Availability:
- Ships Same Business Day
- Weight:
- 0.05 LBS
MSRP: $38.95Now: $37.00Was: $38.95Qty in Cart: 0Quantity:Price:MSRP: $38.95Now: $37.00Was: $38.95Subtotal: -
KIBBLEWHITE Valve - Intake - Tensilite 40-41612T
KIBBLEWHITE
$92.51If you're serious about maximizing valve life and performance on your engine build, OEM intake valves simply won't cut it. Kibblewhite's Black Diamond intake valves are purpose-built from premium...09263389- SKU:
- 09263389
- Availability:
- Ships Same Business Day
- Weight:
- 0.21 LBS
$92.51Qty in Cart: 0Quantity:Price:$92.51Subtotal:
