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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On Sale
PROX Piston Kit - 94.96 mm - Beta 430RR 01.7415.A
PROX
MSRP: $216.95Now: $183.00Was: $216.95A worn or damaged piston directly compromises engine compression, throttle response, and overall reliability—especially critical in high-performance 430RR applications where precision tolerances are non-negotiable. This PROX Piston Kit delivers...09106811- SKU:
- 09106811
- Availability:
- Ships Same Business Day
- Weight:
- 0.50 LBS
MSRP: $216.95Now: $183.00Was: $216.95 -
On Sale
PROX Piston Kit - 99.96 mm - Beta 480RR 01.7425.A
PROX
MSRP: $221.95Now: $183.00Was: $221.95A worn or damaged piston directly impacts engine compression, throttle response, and reliability—especially critical in high-revving two-stroke applications like the Beta 480RR. This PROX piston kit delivers OEM-quality precision with a complete...09106812- SKU:
- 09106812
- Availability:
- Ships Same Business Day
- Weight:
- 0.85 LBS
MSRP: $221.95Now: $183.00Was: $221.95 -
On Sale
PROX Piston Kit - 99.95 mm - Beta 498RR/520RR 01.7512.A
PROX
MSRP: $221.95Now: $183.00Was: $221.95The piston is the heart of your engine's combustion cycle, and worn or damaged pistons will kill performance and reliability. This PROX kit gives you OEM-quality components precision-engineered for your Beta 498RR/520RR, ensuring proper ring sealing,...09106813- SKU:
- 09106813
- Availability:
- Ships Same Business Day
- Weight:
- 0.95 LBS
MSRP: $221.95Now: $183.00Was: $221.95 -
On Sale
PROX Crankshaft Bearing/Seal Kit - Gas Gas/Husqvarna/KTM 23.CBS63017
PROX
MSRP: $169.95Now: $136.00Was: $169.95A worn crankshaft bearing or degraded seal compromises engine reliability and can lead to catastrophic internal damage. This OEM-specification kit delivers complete bearing and seal replacement, restoring your engine's structural integrity and oil...09240707- SKU:
- 09240707
- Availability:
- Ships Same Business Day
- Weight:
- 1.03 LBS
MSRP: $169.95Now: $136.00Was: $169.95 -
On Sale
ATHENA Piston Kit with Gaskets - 71.93 mm - KTM P4C0720045002A
ATHENA
MSRP: $220.95Now: $199.00Was: $220.95Keep your 2-stroke off-road machine running at peak performance with a piston kit engineered for reliability and durability. The ATHENA Piston Kit delivers the same dependability as OE components while offering superior resistance to wear and detonation,...09031776- SKU:
- 09031776
- Availability:
- Ships Same Business Day
- Weight:
- 1.50 LBS
MSRP: $220.95Now: $199.00Was: $220.95 -
On Sale
ATHENA Piston Kit with Gaskets - 71.94 mm - KTM P4C0720045002B
ATHENA
MSRP: $220.95Now: $199.00Was: $220.952-stroke off-road engines demand precision components that survive extreme combustion pressures and repeated thermal cycling. The ATHENA Piston Kit delivers OE-equivalent reliability while improving ring sealing and reducing friction—critical upgrades...09031777- SKU:
- 09031777
- Availability:
- Ships Same Business Day
- Weight:
- 1.49 LBS
MSRP: $220.95Now: $199.00Was: $220.95 -
On Sale
ATHENA Piston Kit with Gaskets - 66.35 mm - Yamaha P4F0664267019B
ATHENA
MSRP: $209.95Now: $189.00Was: $209.95When your 2-stroke off-road engine demands reliability under extreme conditions, OE pistons often fall short on durability and performance. The ATHENA Piston Kit delivers the same factory-level dependability with superior material composition and...09031785- SKU:
- 09031785
- Availability:
- Ships Same Business Day
- Weight:
- 1.30 LBS
MSRP: $209.95Now: $189.00Was: $209.95 -
On Sale
ATHENA Piston Kit with Gaskets - 53.95 mm - Yamaha P4C0540118014A
ATHENA
MSRP: $145.95Now: $131.00Was: $145.95Maintaining proper piston and gasket sealing is critical to preserving compression, fuel efficiency, and power output in 2-stroke off-road engines. This ATHENA kit delivers OE-equivalent reliability with the added durability benefit of high-silicon...09031786- SKU:
- 09031786
- Availability:
- Ships Same Business Day
- Weight:
- 1.00 LBS
MSRP: $145.95Now: $131.00Was: $145.95 -
BOLT Cylinder and Head Nut Universal Kit - 2 Stroke 2STK-HDNUT
BOLT
$14.99Securing your two-stroke top end requires hardware that won't fail under combustion pressure and high RPM loads. This universal kit eliminates the frustration of sourcing individual fasteners by delivering everything you need for cylinder and head...09501032- SKU:
- 09501032
- Availability:
- Ships Same Business Day
- Weight:
- 0.30 LBS
$14.99 -
Hinson Racing Clutch Cover for 2023-2024 KTM 250 SX-F CA480-2301
HINSON RACING
$179.99The stock clutch cover on your 2023-2024 KTM 250 SX-F CA will struggle under sustained racing conditions, leading to heat buildup and potential clutch degradation. The Hinson Racing Clutch Cover CA480-2301 solves this with aerospace-grade T-6 aluminum...09402112- SKU:
- 09402112
- Availability:
- Ships Same Business Day
- Weight:
- 0.75 LBS
$179.99 -
Hinson Racing Clutch Cover for 2020 KTM 250 SX-F CA420-2301
HINSON RACING
$169.99Stock clutch covers fail under sustained track heat and aggressive riding conditions. The Hinson Racing Clutch Cover replaces weak OEM components with billet T-6 aluminum construction, delivering superior heat dissipation and reliability when it matters...09402113- SKU:
- 09402113
- Availability:
- Ships Same Business Day
- Weight:
- 0.62 LBS
$169.99 -
On Sale
PROX Cam Chain - 92RH2015 - 104 Links - Gas Gas | Honda | Husqvarna | KTM | Sherco 31.1335
PROX
MSRP: $99.95Now: $68.00Was: $99.95A compromised cam chain directly impacts engine timing precision and reliability—especially critical in high-demand racing and off-road applications. The PROX 92RH2015 is engineered to OEM specifications with Borg Warner's Japanese manufacturing...09250355- SKU:
- 09250355
- Availability:
- Ships Same Business Day
- Weight:
- 0.46 LBS
MSRP: $99.95Now: $68.00Was: $99.95 -
On Sale
PROX Cam Chain - 82RH2015 - 102 Links - Honda 31.1384
PROX
MSRP: $82.95Now: $68.00Was: $82.95A worn or damaged cam chain compromises valve timing precision and can lead to catastrophic engine damage if it breaks. The PROX 82RH2015 is engineered to OEM specifications and manufactured by Borg Warner in Japan, delivering the durability and...09250356- SKU:
- 09250356
- Availability:
- Ships Same Business Day
- Weight:
- 0.50 LBS
MSRP: $82.95Now: $68.00Was: $82.95 -
On Sale
PROX Cam Chain - 82RH2010 - 112 Links - Honda 31.1496
PROX
MSRP: $99.95Now: $64.00Was: $99.95A worn or failing cam chain compromises valve timing precision, leading to reduced power output, increased emissions, and potential engine damage. The PROX 82RH2010 is engineered to OEM specifications and manufactured by Borg Warner in Japan, delivering...09250362- SKU:
- 09250362
- Availability:
- Ships Same Business Day
- Weight:
- 0.37 LBS
MSRP: $99.95Now: $64.00Was: $99.95 -
On Sale
PROX Cam Chain - 92RH2010 - 114 Links - Gas Gas | Kawasaki | Suzuki | Yamaha 31.2402
PROX
MSRP: $77.95Now: $64.00Was: $77.95A worn or damaged cam chain compromises valve timing precision and can lead to catastrophic engine failure. The PROX 92RH2010 is engineered to OEM specifications with advanced metallurgy and pin construction, delivering the reliability your engine...09250373- SKU:
- 09250373
- Availability:
- Ships Same Business Day
- Weight:
- 0.39 LBS
MSRP: $77.95Now: $64.00Was: $77.95 -
VERTEX Engine Rebuild Kit - Husqvarna | KTM WR00073
VERTEX
$1,225.95A complete engine rebuild requires precision components working in perfect harmony—and sourcing quality parts individually creates delays and compatibility risks. The VERTEX Engine Rebuild Kit consolidates nearly every component you need into one tested,...09031806- SKU:
- 09031806
- Availability:
- Ships Same Business Day
- Weight:
- 14.52 LBS
$1,225.95 -
VERTEX Engine Rebuild Kit - KTM WR00069
VERTEX
$1,225.95A complete engine rebuild demands precision and reliability—cutting corners on component quality will compromise performance and longevity. The VERTEX Engine Rebuild Kit for KTM consolidates nearly every critical internal component into one carefully...09031804- SKU:
- 09031804
- Availability:
- Ships Same Business Day
- Weight:
- 14.52 LBS
$1,225.95 -
BOLT Oil Change Hardware Kit - Gas Gas/Husqvarna/KTM OILCHG-EUR
BOLT
$7.99Proper oil change sealing is critical to maintaining pressure integrity and preventing leaks that compromise engine performance and longevity. This hardware kit ensures you have genuine, OEM-quality components for a complete seal every service interval,...07120672- SKU:
- 07120672
- Availability:
- Ships Same Business Day
- Weight:
- 0.03 LBS
$7.99 -
MOOSE RACING Clutch Cover - Sherco D70-5440MB
MOOSE RACING
$169.95Your Sherco's clutch cover takes constant abuse from heat cycles and impact—OEM aluminum simply isn't engineered to handle sustained high-performance demands. This MOOSE Racing cover replaces it with aircraft-grade billet aluminum that's measurably...09402187- SKU:
- 09402187
- Availability:
- Ships Same Business Day
- Weight:
- 0.76 LBS
$169.95 -
MOOSE RACING Clutch Cover - Yamaha D70-4427MB
MOOSE RACING
$220.95Your clutch cover endures extreme heat and mechanical stress on every ride—stock aluminum simply won't cut it if you're pushing performance. MOOSE Racing's aircraft-grade aluminum cover handles the demands of high-RPM riding with superior strength and...09402188- SKU:
- 09402188
- Availability:
- Ships Same Business Day
- Weight:
- 0.71 LBS
$220.95
