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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MOOSE RACING Piston Kit - 97.00 mm - Can-Am MP9014
MOOSE RACING
$125.95A worn or damaged piston directly undermines engine efficiency, responsiveness, and longevity. The MOOSE RACING Piston Kit delivers OEM-quality reliability with forged construction designed to handle...09106478- SKU:
- 09106478
- Availability:
- Ships Same Business Day
- Weight:
- 1.26 LBS
$125.95Qty in Cart: 0Quantity:Price:$125.95Subtotal: -
MOOSE RACING Piston Kit - 72.96 mm - Xtrainer 300 MSE24569B
MOOSE RACING
$218.95A piston kit is the heart of your engine's combustion cycle—when it fails or wears, your power output and reliability suffer. The MOOSE Racing 72.96 mm Piston Kit delivers OEM-quality construction...09106545- SKU:
- 09106545
- Availability:
- Ships Same Business Day
- Weight:
- 0.85 LBS
$218.95Qty in Cart: 0Quantity:Price:$218.95Subtotal: -
On Sale
ATHENA Complete Gasket Kit - Honda P400210900323
ATHENA
MSRP: $205.95Now: $176.00Was: $205.95A complete gasket kit is essential for any engine rebuild—it ensures proper sealing across all critical surfaces and prevents compression loss, oil leakage, and coolant bypass that can compromise...09347376- SKU:
- 09347376
- Availability:
- Ships Same Business Day
- Weight:
- 0.62 LBS
MSRP: $205.95Now: $176.00Was: $205.95 -
On Sale
ATHENA Top End Gasket Kit - Suzuki P400510600099
ATHENA
MSRP: $72.95Now: $66.00Was: $72.95Engine gaskets are critical sealing components that degrade with heat cycles and wear, directly impacting compression integrity and power output. The ATHENA Top End Gasket Kit gives you the...09347508- SKU:
- 09347508
- Availability:
- Ships Same Business Day
- Weight:
- 0.21 LBS
MSRP: $72.95Now: $66.00Was: $72.95Qty in Cart: 0Quantity:Price:MSRP: $72.95Now: $66.00Was: $72.95Subtotal: -
Cylinder Works Big Bore Gasket Kit 80mm Bore Yamaha YZ250F 2019 CW21013G01
CYLINDER WORKS
$101.95A worn or damaged top-end gasket kit compromises combustion chamber sealing, leading to compression loss and reduced power output. The Cylinder Works Big Bore Gasket Kit ensures a precision fit for...09347521- SKU:
- 09347521
- Availability:
- Ships Same Business Day
- Weight:
- 0.05 LBS
$101.95Qty in Cart: 0Quantity:Price:$101.95Subtotal: -
On Sale
Wossner Piston Kit 72.96mm Beta 300 RR 2022-2026 8324DB
WOSSNER
MSRP: $192.00Now: $182.40Was: $192.00OEM pistons wear out, but a quality replacement kit restores lost compression and throttle response while preventing catastrophic engine failure. The Wossner 72.96mm piston kit for your Beta 300 RR...09106630- SKU:
- 09106630
- Availability:
- Ships Same Business Day
- Weight:
- 0.87 LBS
MSRP: $192.00Now: $182.40Was: $192.00 -
On Sale
Wossner Connecting Rod Kit Yamaha YZ65 2018-2025 P2071
WOSSNER
MSRP: $112.00Now: $106.40Was: $112.00A connecting rod is mission-critical for any high-revving engine—it's the link between combustion force and crankshaft rotation, and failure means catastrophic engine damage. The Wossner P2071 is...09230683- SKU:
- 09230683
- Availability:
- Ships Same Business Day
- Weight:
- 0.25 LBS
MSRP: $112.00Now: $106.40Was: $112.00Qty in Cart: 0Quantity:Price:MSRP: $112.00Now: $106.40Was: $112.00Subtotal: -
On Sale
PROX Connecting Rod Kit - Kawasaki 03.4351
PROX
MSRP: $232.95Now: $195.00Was: $232.95A connecting rod failure at high RPM doesn't just end your day—it ends your engine. The PROX Connecting Rod Kit for Kawasaki engines is engineered to OEM specifications with double-forged...09230698- SKU:
- 09230698
- Availability:
- Ships Same Business Day
- Weight:
- 1.15 LBS
MSRP: $232.95Now: $195.00Was: $232.95 -
On Sale
PROX Connecting Rod Kit - Gas Gas | Husqvarna | KTM 03.6337
PROX
MSRP: $232.95Now: $195.00Was: $232.95A connecting rod is the critical link between your piston and crankshaft—when it fails, your engine fails. The PROX 03.6337 kit uses double-forged construction with optimized grain flow to deliver...09230700- SKU:
- 09230700
- Availability:
- Ships Same Business Day
- Weight:
- 1.20 LBS
MSRP: $232.95Now: $195.00Was: $232.95 -
On Sale
PROX Connecting Rod Kit - Gas Gas | Husqvarna | KTM 03.6343
PROX
MSRP: $232.95Now: $195.00Was: $232.95A connecting rod kit is critical to engine longevity and reliability—especially under high-load riding conditions where OEM components face constant stress. The PROX 03.6343 delivers OEM-equivalent...09230701- SKU:
- 09230701
- Availability:
- Ships Same Business Day
- Weight:
- 0.65 LBS
MSRP: $232.95Now: $195.00Was: $232.95 -
On Sale
PROX Top End Gasket Set - Kawasaki 35.4351
PROX
MSRP: $78.95Now: $64.00Was: $78.95A top-end rebuild demands precision gasket sealing—any leak or failure undermines your entire cylinder head work and costs you performance. The PROX Top End Gasket Set delivers OEM-grade sealing...09347769- SKU:
- 09347769
- Availability:
- Ships Same Business Day
- Weight:
- 0.19 LBS
MSRP: $78.95Now: $64.00Was: $78.95 -
On Sale
PROX Top End Gasket Set - Gas Gas/Husqvarna/KTM 35.6343
PROX
MSRP: $93.95Now: $76.00Was: $93.95Top-end gasket failures compromise cylinder sealing and allow combustion blow-by, robbing your engine of power and reliability. Whether you're rebuilding after a season of hard riding or performing...09347772- SKU:
- 09347772
- Availability:
- Ships Same Business Day
- Weight:
- 0.20 LBS
MSRP: $93.95Now: $76.00Was: $93.95 -
On Sale
PROX Top End Gasket Set - Gas Gas/Husqvarna/KTM 35.6439
PROX
MSRP: $99.95Now: $81.00Was: $99.95A top-end rebuild demands gasket integrity—any leak compromises compression and performance. The PROX Top End Gasket Set delivers OEM-equivalent sealing across all critical combustion chamber...09347777- SKU:
- 09347777
- Availability:
- Ships Same Business Day
- Weight:
- 0.24 LBS
MSRP: $99.95Now: $81.00Was: $99.95 -
On Sale
PROX Piston Kit - 77.96 mm - Kawasaki KX250/KX250X 01.4351.A
PROX
MSRP: $188.95Now: $158.00Was: $188.95A worn or damaged piston directly compromises your KX250/KX250X's compression, throttle response, and overall reliability. The PROX 77.96 mm Piston Kit restores factory performance specifications...09106786- SKU:
- 09106786
- Availability:
- Ships Same Business Day
- Weight:
- 0.40 LBS
MSRP: $188.95Now: $158.00Was: $188.95 -
On Sale
PROX Piston Kit - 71.94 mm - Beta 01.7398.A
PROX
MSRP: $221.95Now: $170.00Was: $221.95When your piston fails, engine performance tanks—and so does your race day. The PROX Piston Kit delivers OEM-equivalent reliability with CNC precision, ensuring consistent compression, proper ring...09106807- SKU:
- 09106807
- Availability:
- Ships Same Business Day
- Weight:
- 0.01 LBS
MSRP: $221.95Now: $170.00Was: $221.95Qty in Cart: 0Quantity:Price:MSRP: $221.95Now: $170.00Was: $221.95Subtotal: -
On Sale
ATHENA Piston Kit with Gaskets - 71.93 mm - KTM P4C0720083002A
ATHENA
MSRP: $220.95Now: $199.00Was: $220.95When you're pushing your KTM 2-stroke off-road machine to its limits, piston failure isn't an option. The ATHENA Piston Kit delivers OE-level reliability with superior durability through high-silicon...09031774- SKU:
- 09031774
- Availability:
- Ships Same Business Day
- Weight:
- 1.57 LBS
MSRP: $220.95Now: $199.00Was: $220.95Qty in Cart: 0Quantity:Price:MSRP: $220.95Now: $199.00Was: $220.95Subtotal: -
On Sale
ATHENA Piston Kit with Gaskets - 71.94 mm - KTM P4C0720083002B
ATHENA
MSRP: $231.95Now: $199.00Was: $231.95If you're running a 2-stroke KTM off-road machine, piston wear directly impacts your power delivery and engine reliability. The ATHENA Piston Kit restores—or exceeds—OE performance with...09031775- SKU:
- 09031775
- Availability:
- Ships Same Business Day
- Weight:
- 1.54 LBS
MSRP: $231.95Now: $199.00Was: $231.95 -
On Sale
ATHENA Piston Kit with Gaskets - 66.35 mm - KTM P4C0664083001B
ATHENA
MSRP: $187.95Now: $161.00Was: $187.95When you're pushing your KTM 2-stroke to its limits, piston reliability directly impacts your performance and race consistency. The ATHENA Piston Kit delivers OE-equivalent durability while reducing...09031779- SKU:
- 09031779
- Availability:
- Ships Same Business Day
- Weight:
- 1.39 LBS
MSRP: $187.95Now: $161.00Was: $187.95Qty in Cart: 0Quantity:Price:MSRP: $187.95Now: $161.00Was: $187.95Subtotal: -
On Sale
ATHENA Piston Kit with Gaskets - 66.35 mm - KTM P4C0664045001B
ATHENA
MSRP: $178.95Now: $161.00Was: $178.95If you're running a 2-stroke off-road bike, piston wear directly impacts throttle response, compression, and overall reliability. The ATHENA Piston Kit delivers OE-level durability with measurably...09031781- SKU:
- 09031781
- Availability:
- Ships Same Business Day
- Weight:
- 1.42 LBS
MSRP: $178.95Now: $161.00Was: $178.95Qty in Cart: 0Quantity:Price:MSRP: $178.95Now: $161.00Was: $178.95Subtotal: -
On Sale
ATHENA Piston Kit with Gaskets - 44.45 mm - Kawasaki P4C0445008001A
ATHENA
MSRP: $121.95Now: $104.00Was: $121.95Your 2-stroke off-road engine demands precision components that can handle extreme combustion pressures and rapid thermal cycling. The ATHENA Piston Kit delivers OE-equivalent reliability with...09031782- SKU:
- 09031782
- Availability:
- Ships Same Business Day
- Weight:
- 0.80 LBS
MSRP: $121.95Now: $104.00Was: $121.95
