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
-
MOOSE OFFROAD Gasket Set - Gas Gas/Husqvarna/KTM 8110044MSE
MOOSE OFFROAD
$166.03A complete engine rebuild demands precision gaskets and seals that won't compromise your engine's integrity under extreme conditions. This MOOSE OFFROAD Gasket Set eliminates the guesswork of sourcing individual components—everything you need for a full...09346918- SKU:
- 09346918
- Availability:
- Ships Same Business Day
- Weight:
- 0.35 LBS
$166.03 -
MOOSE OFFROAD Head Cover Gasket - Yamaha 819200MSE
MOOSE OFFROAD
$51.54A leaking valve cover gasket compromises engine efficiency and risks oil contamination of critical engine components. MOOSE OFFROAD Head Cover Gaskets deliver OEM-equivalent sealing performance at a fraction of the cost, using high-tech molded rubber...09346943- SKU:
- 09346943
- Availability:
- Ships Same Business Day
- Weight:
- 0.09 LBS
$51.54 -
MOOSE OFFROAD Motor Gasket Kit with Oil Seal - Honda 811285MSE
MOOSE OFFROAD
$179.68Engine rebuilds demand precision sealing to prevent oil leaks, compression loss, and catastrophic failure—this comprehensive gasket kit delivers OEM-quality components without the OEM price tag. Whether you're freshening a high-mileage Honda or building...09342209- SKU:
- 09342209
- Availability:
- Ships Same Business Day
- Weight:
- 0.53 LBS
$179.68 -
MOOSE OFFROAD Complete Motor Gasket Kit - Honda 808268MSE
MOOSE OFFROAD
$164.97Engine gasket failure compromises reliability and performance—whether you're rebuilding after a teardown or refreshing an aging powerplant. This complete motor gasket kit eliminates the guesswork of sourcing individual gaskets and seals, giving you every...09341885- SKU:
- 09341885
- Availability:
- Ships Same Business Day
- Weight:
- 0.25 LBS
$164.97Qty in Cart: 0Quantity:Price:$164.97Subtotal: -
MOOSE OFFROAD Valve Seal Kit M60-60490
MOOSE OFFROAD
$15.95OEM valve seals wear out and leak, causing blow-by, oil consumption, and performance loss. The MOOSE OFFROAD Valve Seal Kit M60-60490 replaces your factory seals with precision-engineered components that deliver superior sealing performance and...09262826- SKU:
- 09262826
- Availability:
- Ships Same Business Day
- Weight:
- 0.15 LBS
$15.95 -
On Sale
PROX Gasket Kit - Complete - Suzuki 34.3316
PROX
MSRP: $120.95Now: $98.00Was: $120.95A complete engine rebuild demands precision sealing—and compromising on gasket quality invites oil leaks, compression loss, and catastrophic failure. The PROX Gasket Kit 34.3316 consolidates every seal you need for Suzuki top-end and full-engine...09345576- SKU:
- 09345576
- Availability:
- Ships Same Business Day
- Weight:
- 0.15 LBS
MSRP: $120.95Now: $98.00Was: $120.95Qty in Cart: 0Quantity:Price:MSRP: $120.95Now: $98.00Was: $120.95Subtotal: -
On Sale
PROX Top End Gasket Set - Kawasaki KX 450 F 35.4419
PROX
MSRP: $93.95Now: $76.00Was: $93.95A top-end rebuild demands precision gaskets that won't fail under combustion pressures and extreme heat cycles. The PROX Top End Gasket Set eliminates the risk of compression leaks and coolant seepage that compromise engine performance and reliability...09345771- SKU:
- 09345771
- Availability:
- Ships Same Business Day
- Weight:
- 0.30 LBS
MSRP: $93.95Now: $76.00Was: $93.95 -
On Sale
PROX Top End Gasket Set - Honda 35.1348
PROX
MSRP: $84.95Now: $72.00Was: $84.95A failing top-end gasket set will compromise cylinder head sealing, leading to coolant leaks, oil seepage, and lost compression—all of which degrade engine performance and reliability. The PROX 35.1348 provides everything you need for a complete Honda...09347108- SKU:
- 09347108
- Availability:
- Ships Same Business Day
- Weight:
- 0.25 LBS
MSRP: $84.95Now: $72.00Was: $84.95 -
On Sale
PROX Top End Gasket Set - Honda 35.1419
PROX
MSRP: $84.95Now: $72.00Was: $84.95A top-end rebuild demands gaskets that won't fail under combustion pressures and thermal cycling. The PROX 35.1419 delivers precision-engineered sealing surfaces using premium materials, ensuring your Honda engine maintains compression and prevents...09347111- SKU:
- 09347111
- Availability:
- Ships Same Business Day
- Weight:
- 0.20 LBS
MSRP: $84.95Now: $72.00Was: $84.95Qty in Cart: 0Quantity:Price:MSRP: $84.95Now: $72.00Was: $84.95Subtotal: -
On Sale
PROX Top End Gasket Set - Honda XR650L 35.1623
PROX
MSRP: $67.95Now: $55.00Was: $67.95A top-end rebuild demands precision and reliability—compromise here and you're risking blow-by, compression loss, and catastrophic engine failure. The PROX Top End Gasket Set for the Honda XR650L gives you OEM-equivalent sealing with the durability to...09347118- SKU:
- 09347118
- Availability:
- Ships Same Business Day
- Weight:
- 0.35 LBS
MSRP: $67.95Now: $55.00Was: $67.95 -
On Sale
PROX Top End Gasket Set - Husqvarna/Gas Gas/KTM 35.6216
PROX
MSRP: $72.95Now: $59.00Was: $72.95A top-end rebuild demands precision—worn gaskets compromise compression, invite oil seepage, and undermine engine reliability. The PROX Top End Gasket Set delivers the complete seal integrity your Husqvarna, Gas Gas, or KTM needs to perform consistently...09347147- SKU:
- 09347147
- Availability:
- Ships Same Business Day
- Weight:
- 0.11 LBS
MSRP: $72.95Now: $59.00Was: $72.95 -
On Sale
PROX Top End Gasket Set - Husqvarna/Gas Gas/KTM 35.6319
PROX
MSRP: $89.95Now: $76.00Was: $89.95A leaking or compromised top-end gasket set will compromise combustion efficiency, increase blow-by, and force you back into the shop. This PROX gasket set delivers the precision fit and material durability needed for a complete, reliable top-end rebuild...09347151- SKU:
- 09347151
- Availability:
- Ships Same Business Day
- Weight:
- 0.46 LBS
MSRP: $89.95Now: $76.00Was: $89.95Qty in Cart: 0Quantity:Price:MSRP: $89.95Now: $76.00Was: $89.95Subtotal: -
On Sale
PROX Piston Kit - 71.94 mm - Gas Gas | Husqvarna | KTM 01.6388.A
PROX
MSRP: $189.95Now: $161.00Was: $189.95A piston kit is one of the most critical components in your engine's combustion chamber—it directly impacts power delivery, reliability, and longevity. The PROX 71.94 mm Piston Kit is engineered to OEM specifications using high-silicon-content aluminum...09106266- SKU:
- 09106266
- Availability:
- Ships Same Business Day
- Weight:
- 0.85 LBS
MSRP: $189.95Now: $161.00Was: $189.95Qty in Cart: 0Quantity:Price:MSRP: $189.95Now: $161.00Was: $189.95Subtotal: -
On Sale
PROX Gasket Kit - Complete - Suzuki/Kawasaki 34.4021
PROX
MSRP: $59.95Now: $51.00Was: $59.95A complete engine rebuild demands precision sealing at every junction—this PROX Gasket Kit delivers all the OEM-quality gaskets and seals you need to restore compression, eliminate leaks, and ensure consistent performance on your Suzuki or Kawasaki...09345587- SKU:
- 09345587
- Availability:
- Ships Same Business Day
- Weight:
- 0.15 LBS
MSRP: $59.95Now: $51.00Was: $59.95Qty in Cart: 0Quantity:Price:MSRP: $59.95Now: $51.00Was: $59.95Subtotal: -
On Sale
PROX Gasket Kit - Complete - Suzuki/Kawasaki 34.4100
PROX
MSRP: $46.95Now: $38.00Was: $46.95A complete engine rebuild demands precision—gaskets that seal consistently under load, valve stem seals that hold pressure, and every component engineered to specification. This PROX kit delivers exactly that, eliminating the risk of mismatched...09345589- SKU:
- 09345589
- Availability:
- Ships Same Business Day
- Weight:
- 0.10 LBS
MSRP: $46.95Now: $38.00Was: $46.95 -
On Sale
PROX Top End Gasket Set - Honda CRF450R 35.1429
PROX
MSRP: $104.95Now: $89.00Was: $104.95A top-end rebuild demands precision—and gasket failure isn't an option when you're pushing your CRF450R to the limit. The PROX Top End Gasket Set delivers OEM-grade sealing with materials engineered to withstand sustained high RPM performance and thermal...09345683- SKU:
- 09345683
- Availability:
- Ships Same Business Day
- Weight:
- 0.10 LBS
MSRP: $104.95Now: $89.00Was: $104.95Qty in Cart: 0Quantity:Price:MSRP: $104.95Now: $89.00Was: $104.95Subtotal: -
SHINDY Needle Bearing - 16 mm x 21 mm x 23 mm - Yamaha 10-301
SHINDY
$11.95Piston pin needle bearings are critical to engine reliability, especially in high-RPM applications where precision tolerances demand perfection. This SHINDY bearing delivers the exact dimensions and manufacturing standards your Yamaha engine requires,...NB1455- SKU:
- NB1455
- Availability:
- Ships Same Business Day
- Weight:
- 0.02 LBS
$11.95 -
Twin Air Oil Filter Arctic Cat Kawasaki Suzuki 2000-2025 140007
TWIN AIR
$11.95Clean oil is non-negotiable for engine longevity and performance. The Twin Air Oil Filter 140007 delivers reliable contaminant removal to keep your Arctic Cat, Kawasaki, or Suzuki running at peak efficiency across demanding conditions. With a...140007- SKU:
- 140007
- Availability:
- Ships Same Business Day
- Weight:
- 0.10 LBS
$11.95 -
VERTEX Top End Piston Kit - 66.35 mm - Yamaha YZ250/X VTK22584B-2
VERTEX
$235.95A worn top end compromises power delivery and throttle response on your YZ250/X. This VERTEX piston kit restores OEM performance with precision-cast components engineered for durability and reliable break-in, getting you back to riding with confidence...09103134- SKU:
- 09103134
- Availability:
- Ships Same Business Day
- Weight:
- 1.26 LBS
$235.95 -
VERTEX Piston Kit - 99.95 mm - KTM 23417B
VERTEX
$331.95A quality piston kit is the foundation of reliable engine performance, especially in high-demand racing and off-road applications. The VERTEX 99.95 mm piston kit delivers the durability and power gains your KTM engine needs, combining precision forging...09102627- SKU:
- 09102627
- Availability:
- Ships Same Business Day
- Weight:
- 0.97 LBS
$331.95
