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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VERTEX Piston Kit VTKTC22983A
VERTEX
$302.95A quality piston kit is the foundation of reliable high-RPM performance, and the VERTEX Piston Kit VTKTC22983A delivers the durability and precision demanded by serious builders. The T-5 heat treatment cycle ensures superior hardness and resistance to...09103724- SKU:
- 09103724
- Availability:
- Ships Same Business Day
- Weight:
- 2.05 LBS
$302.95 -
Wiseco Wrist Pin 1985-1986 Honda ATC350X S529
WISECO
$23.99The Wiseco S529 wrist pin is engineered to handle the extreme demands of high-RPM operation in your 1985-1986 Honda ATC350X. This precision-machined component maintains structural integrity under sustained load and elevated combustion temperatures,...S529- SKU:
- S529
- Availability:
- Ships Same Business Day
- Weight:
- 0.12 LBS
- APPLICATION:
- PISTON
- LENGTH:
- 61,3 MM
- LENGTH METRIC:
- 61.3 MM
- MATERIAL:
- ALUMINUM
- PRODUCT NAME:
- WRIST PIN
- OUTSIDE DIAMETER:
- 21,00 MM
- RIDING STYLE:
- ATV
- UNITS:
- EACH
- MATERIAL:
- SILICONE
- OUTSIDE DIAMETER METRIC:
- 21.00 MM
- RIDING STYLE:
- OFF-ROAD
$23.99 -
Wiseco Piston Kit 86mm Bore Yamaha DT400 1975-1978 MX400 1975 232M08600
WISECO
$232.95The Wiseco Piston Kit delivers the reliability and performance precision you need for a complete top-end rebuild on your classic Yamaha DT400 or MX400. This +1.00mm oversized piston compensates for wear and restores compression, giving you crisp throttle...232M08600- SKU:
- 232M08600
- Availability:
- Ships Same Business Day
- Weight:
- 1.15 LBS
- ENGINE TYPE:
- 2-STROKE
- PISTON DIAMETER METRIC:
- 85.92 MM
- PRODUCT NAME:
- PISTON KIT
- STROKE LENGTH METRIC:
- 70.00 MM
- BORE - OVERSIZE METRIC:
- +1.00 MM
- DISPLACEMENT:
- 397 CC
- MODEL:
- FORGED SERIES
- RIDING STYLE:
- ADVENTURE TOURING / DUAL-SPORT
- SKIRT COATING:
- NON-COATED
- UNITS:
- KIT
- BORE - OVERSIZE:
- +1,00 MM
- PISTON MATERIAL:
- 4032 ALUMINUM ALLOY
- RIDING STYLE:
- OFF-ROAD
- BORE SIZE METRIC:
- 86.00 MM
$232.95Qty in Cart: 0Quantity:Price:$232.95Subtotal: -
Wiseco Piston Kit Honda TRX400EX 1999-2008 4606M08700
WISECO
$219.95If you're running a Honda TRX400EX, cylinder wear and stock piston limitations will eventually throttle your engine's potential. The Wiseco Piston Kit 4606M08700 restores combustion efficiency and adds measurable power while maintaining the reliability...09102910- SKU:
- 09102910
- Availability:
- Ships Same Business Day
- Weight:
- 1.15 LBS
- BORE - OVERSIZE METRIC:
- +2.00 MM
- STROKE LENGTH METRIC:
- 70.00 MM
- BORE SIZE METRIC:
- 87.00 MM
- COMPRESSION RATIO IMPERIAL:
- 10.0:1
- DISPLACEMENT:
- 397 CC
- RIDING STYLE:
- OFF-ROAD
- BORE - OVERSIZE:
- +2,00 MM
- ENGINE TYPE:
- 4-STROKE
- PISTON MATERIAL:
- ALUMINUM ALLOY
- PISTON MATERIAL:
- FORGED
- PRODUCT NAME:
- PISTON
- UNITS:
- EACH
$219.95Qty in Cart: 0Quantity:Price:$219.95Subtotal: -
Wiseco Piston Kit 88mm 11:1 Compression for Honda XR400R 1996-2004 4628M08800
WISECO
$244.95Factory pistons wear out—especially in high-demand riding conditions. This Wiseco piston kit restores lost compression and power while delivering the durability needed for both trail abuse and competition. At 88mm with an 11:1 compression ratio, you're...09102915- SKU:
- 09102915
- Availability:
- Ships Same Business Day
- Weight:
- 1.10 LBS
- BORE - OVERSIZE:
- +3,00 MM
- COMPRESSION RATIO IMPERIAL:
- 11.0:1
- ENGINE TYPE:
- 4-STROKE
- PISTON MATERIAL:
- ALUMINUM ALLOY
- PRODUCT NAME:
- PISTON
- RIDING STYLE:
- ATV
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- EACH
- STROKE LENGTH METRIC:
- 70.00 MM
- BORE SIZE METRIC:
- 88.00 MM
- DISPLACEMENT:
- 397 CC
- PISTON MATERIAL:
- FORGED
- BORE - OVERSIZE METRIC:
- +3.00 MM
$244.95Qty in Cart: 0Quantity:Price:$244.95Subtotal: -
Wiseco Piston Kit Yamaha XT350 1985-2000 86mm 9:1 Compression 4674M08600
WISECO
$199.95If you're running a Yamaha XT350 or TT350, a worn or damaged piston directly impacts combustion efficiency, throttle response, and overall reliability. The Wiseco 4674M08600 replaces your factory piston with a precision-engineered component that restores...09102916- SKU:
- 09102916
- Availability:
- Ships Same Business Day
- Weight:
- 0.97 LBS
- BORE - OVERSIZE:
- STANDARD
- BORE - OVERSIZE METRIC:
- STANDARD
- DISPLACEMENT:
- 346 CC
- ENGINE TYPE:
- 4-STROKE
- RIDING STYLE:
- OFF-ROAD
- STROKE LENGTH METRIC:
- 59.60 MM
- BORE SIZE METRIC:
- 86.00 MM
- PISTON MATERIAL:
- ALUMINUM ALLOY
- PISTON MATERIAL:
- FORGED
- PRODUCT NAME:
- PISTON
- UNITS:
- EACH
- COMPRESSION RATIO IMPERIAL:
- 9.0:1
$199.95Qty in Cart: 0Quantity:Price:$199.95Subtotal: -
Wiseco Piston Kit Yamaha XT350 1985-2000 87.50mm 9:1 4674M08750
WISECO
$184.95When your XT350 starts showing signs of wear—loss of compression, reduced throttle response, or visible piston scoring—a quality piston kit is essential to restore engine integrity and performance. The Wiseco 4674M08750 is engineered specifically for...09102917- SKU:
- 09102917
- Availability:
- Ships Same Business Day
- Weight:
- 1.01 LBS
- ENGINE TYPE:
- 4-STROKE
- PISTON MATERIAL:
- ALUMINUM ALLOY
- PISTON MATERIAL:
- FORGED
- PRODUCT NAME:
- PISTON
- UNITS:
- EACH
- BORE - OVERSIZE:
- +1,00 MM
- BORE SIZE METRIC:
- 87.00 MM
- DISPLACEMENT:
- 346 CC
- STROKE LENGTH METRIC:
- 59.60 MM
- BORE - OVERSIZE METRIC:
- +1.00 MM
- COMPRESSION RATIO IMPERIAL:
- 9.0:1
- RIDING STYLE:
- ADVENTURE TOURING / DUAL-SPORT
$184.95 -
Wiseco Piston Kit 88.00mm Oversize Yamaha YZ490 1984-1990 546M08800
WISECO
$243.95If you're running a YZ490 and want to unlock real gains in compression ratio and top-end power, a quality oversize piston is non-negotiable. The Wiseco +1.00mm kit gives you the forged strength to handle aggressive tuning and racing demands while...546M08800- SKU:
- 546M08800
- Availability:
- Ships Same Business Day
- Weight:
- 1.40 LBS
- BORE - OVERSIZE METRIC:
- +1.00 MM
- RIDING STYLE:
- OFF-ROAD
- PISTON MATERIAL:
- ALUMINUM ALLOY
- UNITS:
- EACH
- DISPLACEMENT:
- 487 CC
- STROKE LENGTH:
- 82,00 MM
- BORE - OVERSIZE:
- +1,00 MM
- BORE SIZE METRIC:
- 88.00 MM
- PISTON MATERIAL:
- FORGED
- PRODUCT NAME:
- PISTON
- STROKE LENGTH METRIC:
- 82.00 MM
$243.95 -
Wiseco Piston 88.5mm Oversize Yamaha WR500Z 1992-1993 546M08850
WISECO
$244.95If you're pushing your Yamaha WR500Z or YZ490 to its limits, stock pistons won't cut it. The Wiseco +1.50mm oversize piston delivers the durability and power you need for serious trail and racing applications, with forged construction that handles...546M08850- SKU:
- 546M08850
- Availability:
- Ships Same Business Day
- Weight:
- 1.25 LBS
- BORE - OVERSIZE METRIC:
- +1.50 MM
- PISTON MATERIAL:
- FORGED
- STROKE LENGTH METRIC:
- 82.00 MM
- BORE SIZE METRIC:
- 88.50 MM
- DISPLACEMENT:
- 487 CC
- STROKE LENGTH:
- 82,00 MM
- PISTON MATERIAL:
- ALUMINUM ALLOY
- PRODUCT NAME:
- PISTON
- BORE - OVERSIZE:
- +1,50 MM
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- EACH
$244.95Qty in Cart: 0Quantity:Price:$244.95Subtotal: -
Wiseco Piston 89mm +2mm Oversize for Yamaha YZ490 1984-1990 546M08900
WISECO
$244.95If you're running a Yamaha YZ490 or WR500 at the edge of its limits, factory pistons won't cut it. This Wiseco forged piston is built to withstand the punishment of competitive racing and aggressive trail riding while delivering measurable gains in...546M08900- SKU:
- 546M08900
- Availability:
- Ships Same Business Day
- Weight:
- 1.25 LBS
- BORE - OVERSIZE METRIC:
- +2.00 MM
- DISPLACEMENT:
- 487 CC
- PISTON MATERIAL:
- ALUMINUM ALLOY
- STROKE LENGTH:
- 82,00 MM
- UNITS:
- EACH
- BORE - OVERSIZE:
- +2,00 MM
- PISTON MATERIAL:
- FORGED
- PRODUCT NAME:
- PISTON
- RIDING STYLE:
- OFF-ROAD
- BORE SIZE METRIC:
- 89.00 MM
- STROKE LENGTH METRIC:
- 82.00 MM
$244.95Qty in Cart: 0Quantity:Price:$244.95Subtotal: -
Wiseco Cam Chain for Yamaha YFM660F Grizzly 2002-2008 and YXR660F Rhino 2004-2007 CC020
WISECO
$89.95Your Yamaha Grizzly or Rhino's cam chain is critical to maintaining precise valve timing and engine reliability—especially if you're pushing performance or logging serious trail miles. A worn or compromised cam chain leads to timing slippage, reduced...09250647- SKU:
- 09250647
- Availability:
- Ships Same Business Day
- Weight:
- 0.46 LBS
- TYPE:
- CAM
- CHAIN SIZE:
- 92RH2010
- NUMBER OF LINKS:
- 126
- UNITS:
- EACH
- PRODUCT NAME:
- CHAIN
- RIDING STYLE:
- UTV
- RIDING STYLE:
- ATV
$89.95Qty in Cart: 0Quantity:Price:$89.95Subtotal: -
Wiseco CRF450R 2009-2016 Connecting Rod Kit WPR1409
WISECO
$435.95Stock connecting rods are often the first component to fail under sustained high RPM racing loads. The Wiseco WPR1409 replaces that weak link with billet aluminum construction that handles extreme combustion pressures while reducing rotating mass for...09230594- SKU:
- 09230594
- Availability:
- Ships Same Business Day
- Weight:
- 1.76 LBS
- PRODUCT NAME:
- CONNECTING ROD KIT
- TYPE:
- RACER ELITE
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
$435.95Qty in Cart: 0Quantity:Price:$435.95Subtotal: -
Wiseco YZ250 2002-2025 Ring Set 2614CS
WISECO
$25.95The Wiseco 2614CS ring set is engineered to restore proper cylinder sealing and compression in your YZ250, directly translating to stronger power delivery and improved fuel efficiency across the RPM range. Whether you're rebuilding after a top-end...09120106- SKU:
- 09120106
- Availability:
- Ships Same Business Day
- Weight:
- 0.03 LBS
- BORE SIZE METRIC:
- 66.40 MM
- PISTON MATERIAL:
- ALUMINUM
- DISPLACEMENT:
- 249 CC
- PRODUCT NAME:
- PISTON RING
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- SET
$25.95 -
Wiseco 39mm Piston Ring Set for Honda CRF50F 2004-2013 3900XZ
WISECO
$46.95When your Honda CRF50F's piston rings wear, compression drops and power bleeds away—along with fuel efficiency and engine longevity. The Wiseco 3900XZ ring set restores proper cylinder sealing with precision-engineered rings that maintain consistent...09120107- SKU:
- 09120107
- Availability:
- Ships Same Business Day
- Weight:
- 0.05 LBS
- UNITS:
- SET
- DISPLACEMENT:
- 49,50 CC
- RIDING STYLE:
- STREET
- BORE SIZE METRIC:
- 39.00 MM
- PISTON MATERIAL:
- ALUMINUM
- PRODUCT NAME:
- PISTON RING
- RIDING STYLE:
- OFF-ROAD
$46.95 -
Wiseco 48.50mm Piston Ring Set for Honda CRF70F 2004-2012 XR70R 1997-2003 XR80 1979-1984 Polaris Outlaw 90 2007-2014 1909XE
WISECO
$44.95Worn or damaged piston rings compromise compression, increase blow-by, and rob your engine of power and efficiency. The Wiseco 1909XE Ring Set restores proper sealing and combustion integrity, making it essential for any engine rebuild or performance...09120115- SKU:
- 09120115
- Availability:
- Ships Same Business Day
- Weight:
- 0.05 LBS
- BORE SIZE METRIC:
- 48.50 MM
- DISPLACEMENT:
- 79,7 CC
- PRODUCT NAME:
- PISTON RING
- RIDING STYLE:
- OFF-ROAD
- PISTON MATERIAL:
- ALUMINUM
- UNITS:
- SET
$44.95Qty in Cart: 0Quantity:Price:$44.95Subtotal: -
Wiseco Valve Kit 2004-2006 Kawasaki KX250F and Suzuki RM-Z250 SVKB4335
WISECO
$365.95Stock valve springs wear down under aggressive riding, causing valve float and losing power when you need it most. The Wiseco SVKB4335 replaces your worn intake and exhaust valves with premium steel units and precision-engineered springs rated for...09263075- SKU:
- 09263075
- Availability:
- Ships Same Business Day
- Weight:
- 0.55 LBS
- APPLICATION:
- INTAKE
- MATERIAL:
- STEEL
- PRODUCT NAME:
- VALVE KIT
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- APPLICATION:
- EXHAUST
$365.95 -
Wiseco Steel Valve Kit for 2009-2010 Kawasaki KX250F SVKB4338
WISECO
$365.95Stock valve springs and steel valves on your 2009-2010 KX250F can't reliably handle the demands of consistent racing or high-RPM riding. This Wiseco Steel Valve Kit replaces those components with precision-engineered intake and exhaust valves paired with...09263077- SKU:
- 09263077
- Availability:
- Ships Same Business Day
- Weight:
- 0.95 LBS
- APPLICATION:
- EXHAUST
- APPLICATION:
- INTAKE
- MATERIAL:
- STEEL
- PRODUCT NAME:
- VALVE KIT
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
$365.95 -
Wiseco Valve Kit KX250F 2011-2016 SVKB4341
WISECO
$365.95Stock valve springs lose tension over time, compromising ignition timing and throttle response on your KX250F. The Wiseco Valve Kit SVKB4341 replaces worn intake and exhaust valves with precision-matched components engineered to handle sustained RPMs and...09263078- SKU:
- 09263078
- Availability:
- Ships Same Business Day
- Weight:
- 0.95 LBS
- APPLICATION:
- EXHAUST
- PRODUCT NAME:
- VALVE KIT
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- APPLICATION:
- INTAKE
- MATERIAL:
- STEEL
$365.95 -
Wiseco Steel Valve Set Kawasaki KX450F 2006-2008 SVKB4406
WISECO
$391.95Your KX450F's valve train demands precision components that can withstand the rigors of competitive riding and high-RPM operation. This Wiseco steel valve set delivers OEM-quality construction with performance-grade materials, ensuring consistent...09263079- SKU:
- 09263079
- Availability:
- Ships Same Business Day
- Weight:
- 0.35 LBS
- APPLICATION:
- EXHAUST
- UNITS:
- KIT
- MATERIAL:
- STEEL
- PRODUCT NAME:
- VALVE KIT
- RIDING STYLE:
- OFF-ROAD
- APPLICATION:
- INTAKE
- RIDING STYLE:
- ATV
$391.95 -
Wiseco Valve Kit KX450F 2009-2018 SVKB4409
WISECO
$391.95Valve train wear is one of the fastest ways to lose compression and throttle response on your KX450F. The Wiseco Valve Kit SVKB4409 replaces worn intake and exhaust valves with precision-engineered components that restore your engine's sealing integrity...09263080- SKU:
- 09263080
- Availability:
- Ships Same Business Day
- Weight:
- 1.15 LBS
- APPLICATION:
- EXHAUST
- MATERIAL:
- STEEL
- PRODUCT NAME:
- VALVE KIT
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- APPLICATION:
- INTAKE
$391.95
