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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MOOSE OFFROAD Gasket Set with Oil Seal - Honda 8110036MSE
MOOSE OFFROAD
$178.50A complete engine and transmission rebuild demands precision sealing at every junction—and this comprehensive gasket set eliminates the guesswork by including every gasket, O-ring, and valve seal you...09346917- SKU:
- 09346917
- Availability:
- Ships Same Business Day
- Weight:
- 0.39 LBS
$178.50Qty in Cart: 0Quantity:Price:$178.50Subtotal: -
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...09346918- SKU:
- 09346918
- Availability:
- Ships Same Business Day
- Weight:
- 0.35 LBS
$166.03Qty in Cart: 0Quantity:Price:$166.03Subtotal: -
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...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...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...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...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...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...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...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...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...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...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...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 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...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...09345589- SKU:
- 09345589
- Availability:
- Ships Same Business Day
- Weight:
- 0.10 LBS
MSRP: $46.95Now: $38.00Was: $46.95Qty in Cart: 0Quantity:Price:MSRP: $46.95Now: $38.00Was: $46.95Subtotal: -
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...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...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...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...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...09102627- SKU:
- 09102627
- Availability:
- Ships Same Business Day
- Weight:
- 0.97 LBS
$331.95
