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
-
Wiseco Piston Kit for Honda CR250R 2005-2007 66.40mm PK1381
WISECO
$309.95The Wiseco PK1381 is engineered for CR250R riders who need a proven top-end rebuild that restores or exceeds factory performance. If you're experiencing power loss, worn compression, or simply demand race-proven components, this complete piston kit...09030550- SKU:
- 09030550
- Availability:
- Ships Same Business Day
- Weight:
- 1.44 LBS
- COOLING SYSTEM:
- LIQUID COOLED
- DISPLACEMENT:
- 249 CC
- BORE - OVERSIZE:
- STANDARD
- BORE - OVERSIZE METRIC:
- STANDARD
- BORE SIZE METRIC:
- 66.40 MM
- MODEL:
- RACER'S CHOICE
- PISTON MATERIAL:
- ALUMINUM
- PISTON MATERIAL:
- FORGED
- UNITS:
- EACH
- PRODUCT NAME:
- REBUILD KIT
- STROKE LENGTH METRIC:
- 72.00 MM
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- TOP END
$309.95 -
Wiseco Honda CRF450R 2002-2008 Piston Kit PK1233
WISECO
$390.95When you're rebuilding a CRF450R top end, you need a piston kit that matches the precision your engine demands. The Wiseco PK1233 delivers the bore accuracy and compression ratio necessary for consistent power gains and extended durability, whether...09030552- SKU:
- 09030552
- Availability:
- Ships Same Business Day
- Weight:
- 1.55 LBS
- BORE SIZE METRIC:
- 96.00 MM
- MODEL:
- FORGED SERIES
- BORE - OVERSIZE:
- STANDARD
- BORE - OVERSIZE METRIC:
- STANDARD
- DISPLACEMENT:
- 449 CC
- PISTON DIAMETER METRIC:
- 95.94 MM
- SKIRT COATING:
- ARMORGLIDE®
- UNITS:
- KIT
- COMPRESSION RATIO IMPERIAL:
- 12.5:1
- PRODUCT NAME:
- REBUILD KIT
- STROKE LENGTH METRIC:
- 62.10 MM
- ENGINE TYPE:
- 4-STROKE
- PISTON MATERIAL:
- 2618 ALUMINUM ALLOY
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- TOP END
$390.95Qty in Cart: 0Quantity:Price:$390.95Subtotal: -
Wiseco Piston Kit 77mm 13.1:1 for 2004-2005 Kawasaki KX250F PK1237
WISECO
$308.95A complete top-end rebuild demands precision components that can handle sustained high RPMs and aggressive tuning. The Wiseco PK1237 delivers race-proven engineering in a bolt-together package, letting you maximize combustion efficiency without guesswork...09030555- SKU:
- 09030555
- Availability:
- Ships Same Business Day
- Weight:
- 1.10 LBS
- BORE - OVERSIZE METRIC:
- STANDARD
- PISTON MATERIAL:
- 2618 ALUMINUM ALLOY
- PRODUCT NAME:
- REBUILD KIT
- BORE - OVERSIZE:
- STANDARD
- BORE SIZE METRIC:
- 77.00 MM
- DISPLACEMENT:
- 250 CC
- ENGINE TYPE:
- 4-STROKE
- MODEL:
- FORGED SERIES
- SKIRT COATING:
- NON-COATED
- STROKE LENGTH METRIC:
- 53.60 MM
- COMPRESSION RATIO IMPERIAL:
- 13.1:1
- PISTON DIAMETER METRIC:
- 76.96 MM
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- TOP END
- UNITS:
- KIT
$308.95Qty in Cart: 0Quantity:Price:$308.95Subtotal: -
Wiseco Yamaha WR250F 2005-2013 Piston Kit PK1384
WISECO
$344.95When your WR250F's top end shows wear, you lose compression, reliability, and the crisp power delivery that keeps you competitive. The Wiseco PK1384 restores full performance with OEM-quality pistons and a complete gasket set, eliminating guesswork...09030558- SKU:
- 09030558
- Availability:
- Ships Same Business Day
- Weight:
- 1.15 LBS
- ENGINE TYPE:
- 4-STROKE
- PISTON MATERIAL:
- 2618 ALUMINUM ALLOY
- TYPE:
- TOP END
- PISTON DIAMETER METRIC:
- 76.95 MM
- PRODUCT NAME:
- REBUILD KIT
- BORE - OVERSIZE:
- STANDARD
- BORE - OVERSIZE METRIC:
- STANDARD
- COMPRESSION RATIO IMPERIAL:
- 13.5:1
- RIDING STYLE:
- OFF-ROAD
- SKIRT COATING:
- ARMORGLIDE®
- UNITS:
- KIT
- BORE SIZE METRIC:
- 77.00 MM
- DISPLACEMENT:
- 250 CC
- MODEL:
- FORGED SERIES
- RIDING STYLE:
- STREET
- STROKE LENGTH METRIC:
- 53.60 MM
$344.95Qty in Cart: 0Quantity:Price:$344.95Subtotal: -
Wiseco YZ250F 2005-2007 WR250F 2005-2013 Piston Kit with Gaskets PK1401
WISECO
$299.95When your YZ250F or WR250F starts showing signs of wear—loss of compression, rough idle, or declining power—a top-end rebuild is often the most cost-effective way to restore full performance. The Wiseco PK1401 gives you OEM-quality components with proven...09030559- SKU:
- 09030559
- Availability:
- Ships Same Business Day
- Weight:
- 1.25 LBS
- BORE - OVERSIZE:
- STANDARD
- ENGINE TYPE:
- 4-STROKE
- PISTON MATERIAL:
- 2618 ALUMINUM ALLOY
- PRODUCT NAME:
- REBUILD KIT
- BORE - OVERSIZE METRIC:
- STANDARD
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- COMPRESSION RATIO IMPERIAL:
- 12.5:1
- PISTON DIAMETER METRIC:
- 76.95 MM
- TYPE:
- TOP END
- BORE SIZE METRIC:
- 77.00 MM
- DISPLACEMENT:
- 250 CC
- MODEL:
- FORGED SERIES
- SKIRT COATING:
- NON-COATED
- STROKE LENGTH METRIC:
- 53.60 MM
$299.95Qty in Cart: 0Quantity:Price:$299.95Subtotal: -
Wiseco Piston Kit Standard 39mm 11:1 Compression Honda Z50R 1982-1987 4828M03900
WISECO
$119.95If you're running a Honda Z50R and want to maximize power output without sacrificing reliability, the Wiseco 4828M03900 piston kit delivers the compression ratio and material quality needed for consistent performance gains. The 11:1 compression ratio...09100738- SKU:
- 09100738
- Availability:
- Ships Same Business Day
- Weight:
- 0.20 LBS
- PISTON MATERIAL:
- FORGED
- RIDING STYLE:
- STREET
- STROKE LENGTH METRIC:
- 41.40 MM
- COMPRESSION RATIO IMPERIAL:
- 11.0:1
- BORE - OVERSIZE:
- STANDARD
- BORE - OVERSIZE METRIC:
- STANDARD
- PRODUCT NAME:
- PISTON
- BORE SIZE METRIC:
- 39.00 MM
- DISPLACEMENT:
- 49,50 CC
- ENGINE TYPE:
- 4-STROKE
- PISTON MATERIAL:
- ALUMINUM ALLOY
- UNITS:
- EACH
$119.95Qty in Cart: 0Quantity:Price:$119.95Subtotal: -
Wiseco Piston Kit Sea-Doo 650 1993-1994 WK1118
WISECO
$392.70If you're running a Sea-Doo 650 and want to restore lost compression or build additional power, piston replacement is non-negotiable. The Wiseco WK1118 delivers the precision fit and material quality that separates reliable performance from catastrophic...WK1118- SKU:
- WK1118
- Availability:
- Ships Same Business Day
- Weight:
- 2.63 LBS
- BORE SIZE METRIC:
- 79.00 MM
- MODEL:
- FORGED SERIES
- PRODUCT NAME:
- REBUILD KIT
- BORE - OVERSIZE:
- +1,00 MM
- PISTON DIAMETER METRIC:
- 73.90 MM
- PISTON MATERIAL:
- 4032 ALUMINUM ALLOY
- RIDING STYLE:
- WATERCRAFT
- BORE - OVERSIZE METRIC:
- +1.00 MM
- DISPLACEMENT:
- 666 CC
- UNITS:
- KIT
- ENGINE TYPE:
- 2-STROKE
- SKIRT COATING:
- NON-COATED
- TYPE:
- TOP END
$392.70 -
Wiseco Piston Kit Sea Doo XP Limited 1998-1999 951 040 WK1213
WISECO
$459.57If you're running a 1998-1999 Sea-Doo XP Limited 951, piston quality directly impacts how much power you can reliably extract from your engine. The Wiseco WK1213 delivers CNC-machined Pro-Lite pistons built from aerospace-grade forged aluminum—the same...WK1213- SKU:
- WK1213
- Availability:
- Ships Same Business Day
- Weight:
- 3.25 LBS
- SKIRT COATING:
- NON-COATED
- TYPE:
- TOP END
- UNITS:
- KIT
- BORE - OVERSIZE METRIC:
- +1.00 MM
- DISPLACEMENT:
- 971 CC
- ENGINE TYPE:
- 2-STROKE
- MODEL:
- FORGED SERIES
- BORE - OVERSIZE:
- +1,00 MM
- BORE SIZE METRIC:
- 89.00 MM
- PISTON MATERIAL:
- 4032 ALUMINUM ALLOY
- RIDING STYLE:
- WATERCRAFT
- PISTON DIAMETER METRIC:
- 88.90 MM
- PRODUCT NAME:
- REBUILD KIT
$459.57 -
Wiseco Piston Kit Yamaha GP1200 1997-1999 WK1313
WISECO
$594.95If you're running a Yamaha GP1200, piston wear directly impacts throttle response, fuel efficiency, and engine longevity. The Wiseco WK1313 restores—or exceeds—OEM performance with a complete overhaul kit that includes rings and gaskets, eliminating...WK1313- SKU:
- WK1313
- Availability:
- Ships Same Business Day
- Weight:
- 4.70 LBS
- BORE SIZE METRIC:
- 84.50 MM
- MODEL:
- FORGED SERIES
- RIDING STYLE:
- WATERCRAFT
- BORE - OVERSIZE:
- +0,50 MM
- PISTON DIAMETER METRIC:
- 84.37 MM
- SKIRT COATING:
- NON-COATED
- UNITS:
- KIT
- BORE - OVERSIZE METRIC:
- +0.50 MM
- PRODUCT NAME:
- REBUILD KIT
- TYPE:
- TOP END
- DISPLACEMENT:
- 1142 CC
- ENGINE TYPE:
- 2-STROKE
- PISTON MATERIAL:
- 4032 ALUMINUM ALLOY
$594.95 -
On Sale
Wiseco Piston Kit Yamaha GP 1200 WaveRunner 1997-1999 1 mm WK1314
WISECO
MSRP: $581.67Now: $372.00Was: $581.67Factory pistons won't survive sustained high-RPM operation in a 2-stroke watercraft—thermal stress and detonation will cause catastrophic failure. The Wiseco WK1314 kit is engineered specifically for the Yamaha GP 1200 with forged aluminum construction...WK1314- SKU:
- WK1314
- Availability:
- Ships Same Business Day
- Weight:
- 4.70 LBS
- BORE SIZE METRIC:
- 85.00 MM
- DISPLACEMENT:
- 1156 CC
- MODEL:
- FORGED SERIES
- PRODUCT NAME:
- REBUILD KIT
- BORE - OVERSIZE:
- +1,00 MM
- PISTON MATERIAL:
- 4032 ALUMINUM ALLOY
- RIDING STYLE:
- WATERCRAFT
- BORE - OVERSIZE METRIC:
- +1.00 MM
- ENGINE TYPE:
- 2-STROKE
- UNITS:
- KIT
- PISTON DIAMETER METRIC:
- 84.87 MM
- SKIRT COATING:
- NON-COATED
- TYPE:
- TOP END
MSRP: $581.67Now: $372.00Was: $581.67 -
Wiseco Piston Kit Honda CRF150F 2006-2017 57.5mm 10:1 Compression 40132M05750
WISECO
$154.95If you're running a Honda CRF150F and want measurable gains in power and throttle response, a high-compression piston upgrade is one of the most direct paths to performance. The Wiseco 40132M05750 delivers the kind of engineering precision that separates...09103946- SKU:
- 09103946
- Availability:
- Ships Same Business Day
- Weight:
- 0.40 LBS
- COMPRESSION RATIO IMPERIAL:
- 10.0:1
- BORE SIZE METRIC:
- 57.50 MM
- BORE - OVERSIZE METRIC:
- STANDARD
- ENGINE TYPE:
- 4-STROKE
- PISTON MATERIAL:
- ALUMINUM ALLOY
- PISTON MATERIAL:
- FORGED
- PRODUCT NAME:
- PISTON
- STROKE LENGTH METRIC:
- 57.50 MM
- UNITS:
- EACH
- BORE - OVERSIZE:
- STANDARD
- RIDING STYLE:
- OFF-ROAD
$154.95Qty in Cart: 0Quantity:Price:$154.95Subtotal: -
Wiseco Piston Kit Kawasaki KX100 1995-2021 RE907M05450
WISECO
$154.95The Wiseco RE907M05450 Racer Elite Piston Kit delivers the precision engineering your KX100 demands when you're pushing hard on the track. With a 54.50 mm bore and advanced alloy construction, this kit handles the thermal stress and detonation that come...09105094- SKU:
- 09105094
- Availability:
- Ships Same Business Day
- Weight:
- 0.45 LBS
- BORE SIZE METRIC:
- 54.50 MM
- UNITS:
- KIT
- BORE - OVERSIZE:
- +2,00 MM
- BORE - OVERSIZE METRIC:
- +2.00 MM
- ENGINE TYPE:
- 2-STROKE
- PRODUCT NAME:
- PISTON KIT
- SKIRT COATING:
- ARMORFIT™
- PISTON MATERIAL:
- 2000 SERIES ALLOY
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- RACER ELITE
- PISTON MATERIAL:
- FORGED
$154.95Qty in Cart: 0Quantity:Price:$154.95Subtotal: -
Wiseco Piston Kit Kawasaki KX125 2001-2005 58.00mm RE927M05800
WISECO
$204.95If you're running a KX125 in competitive environments, piston durability and ring sealing directly impact your lap times and engine reliability. This Wiseco Racer Elite kit delivers the precision bore diameter and advanced coatings necessary to maintain...09105096- SKU:
- 09105096
- Availability:
- Ships Same Business Day
- Weight:
- 0.50 LBS
- BORE - OVERSIZE:
- +4,00 MM
- ENGINE TYPE:
- 2-STROKE
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- RACER ELITE
- UNITS:
- KIT
- PISTON MATERIAL:
- FORGED
- PISTON MATERIAL:
- 2000 SERIES ALLOY
- BORE - OVERSIZE METRIC:
- +4.00 MM
- BORE SIZE METRIC:
- 58.00 MM
- PRODUCT NAME:
- PISTON KIT
- SKIRT COATING:
- ARMORFIT™
$204.95Qty in Cart: 0Quantity:Price:$204.95Subtotal: -
Wiseco Piston Kit for 1997-1999 Suzuki RM125 PK1137
WISECO
$212.95If you're running a 1997-1999 Suzuki RM125 and want measurable gains in acceleration and throttle response, a quality piston kit is one of the highest-ROI upgrades you can make. The Wiseco PK1137 Pro-Lite delivers the precision engineering and durability...09030290- SKU:
- 09030290
- Availability:
- Ships Same Business Day
- Weight:
- 0.80 LBS
- MODEL:
- PRO-LITE
- RIDING STYLE:
- OFF-ROAD
- SKIRT COATING:
- NON-COATED
- STROKE LENGTH METRIC:
- 54.00 MM
- UNITS:
- KIT
- BORE SIZE METRIC:
- 54.00 MM
- ENGINE TYPE:
- 2-STROKE
- PRODUCT NAME:
- REBUILD KIT
- TYPE:
- TOP END
- DISPLACEMENT:
- 123 CC
- PISTON DIAMETER METRIC:
- 53.96 MM
- BORE - OVERSIZE:
- STANDARD
- BORE - OVERSIZE METRIC:
- STANDARD
- PISTON MATERIAL:
- 4032 ALUMINUM ALLOY
$212.95Qty in Cart: 0Quantity:Price:$212.95Subtotal: -
Wiseco Valve Kit YZ250F 2001-2013 SVKB2402
WISECO
$445.95Worn or degraded valves compromise combustion efficiency and can lead to costly engine damage. The Wiseco Valve Kit SVKB2402 restores your YZ250F's intake and exhaust flow with precision-engineered components that handle the demands of high-RPM racing...09263065- SKU:
- 09263065
- Availability:
- Ships Same Business Day
- Weight:
- 1.00 LBS
- MATERIAL:
- STEEL
- PRODUCT NAME:
- VALVE KIT
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- APPLICATION:
- EXHAUST
- APPLICATION:
- INTAKE
$445.95Qty in Cart: 0Quantity:Price:$445.95Subtotal: -
Wiseco 54mm Racer Elite Piston Kit for 1995-2003 Honda CR125R RE908M05400
WISECO
$221.95If you're running a CR125R that's seeing serious track time, piston wear is inevitable—and a worn piston kills compression, throttle response, and overall power delivery. The Wiseco RE908M05400 Racer Elite kit gives you OEM-spec fitment with race-proven...09105078- SKU:
- 09105078
- Availability:
- Ships Same Business Day
- Weight:
- 0.50 LBS
- PRODUCT NAME:
- PISTON KIT
- SKIRT COATING:
- ARMORFIT™
- BORE - OVERSIZE:
- STANDARD
- BORE - OVERSIZE METRIC:
- STANDARD
- PISTON MATERIAL:
- FORGED
- BORE SIZE METRIC:
- 54.00 MM
- PISTON MATERIAL:
- 2000 SERIES ALLOY
- ENGINE TYPE:
- 2-STROKE
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- RACER ELITE
- UNITS:
- KIT
$221.95 -
Wiseco Valve Kit for Suzuki RM-Z250 2007-2020 SVKB3338
WISECO
$365.95Stock valve assemblies on your RM-Z250 wear down quickly under aggressive riding, causing loss of compression and compromised engine response. The Wiseco SVKB3338 Valve Kit delivers a complete solution with matched steel valves and precision springs that...09263070- SKU:
- 09263070
- Availability:
- Ships Same Business Day
- Weight:
- 0.95 LBS
- PRODUCT NAME:
- VALVE KIT
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- APPLICATION:
- EXHAUST
- MATERIAL:
- STEEL
- APPLICATION:
- INTAKE
$365.95 -
Wiseco Piston Standard Kawasaki KX 250 1992-2001 617M06640
WISECO
$221.95If you're running a KX250 hard enough to wear out the original piston, you need a replacement that matches your commitment to performance. The Wiseco 617M06640 delivers the precision bore diameter and lightweight construction required to maintain...617M06640- SKU:
- 617M06640
- Availability:
- Ships Same Business Day
- Weight:
- 0.80 LBS
- DISPLACEMENT:
- 249 CC
- STROKE LENGTH:
- 70,00 MM
- BORE SIZE METRIC:
- 66.40 MM
- PISTON MATERIAL:
- ALUMINUM ALLOY
- PISTON MATERIAL:
- FORGED
- PRODUCT NAME:
- PISTON
- BORE - OVERSIZE:
- STANDARD
- BORE - OVERSIZE METRIC:
- STANDARD
- RIDING STYLE:
- OFF-ROAD
- STROKE LENGTH METRIC:
- 70.00 MM
- UNITS:
- EACH
$221.95 -
Wiseco Top End Bearing for Kawasaki KX250 1978-2007 B1022
WISECO
$25.95The Wiseco B1022 top end bearing is engineered to withstand the extreme RPM demands of high-performance KX250 engines, delivering the reliability needed when you're pushing your bike to its limits. A failed top end bearing means catastrophic engine...B1022X- SKU:
- B1022X
- Availability:
- Ships Same Business Day
- Weight:
- 0.13 LBS
- LENGTH METRIC:
- 23.5 MM
- MATERIAL:
- ALUMINUM
- OUTSIDE DIAMETER METRIC:
- 22 MM
- RIDING STYLE:
- ADVENTURE TOURING / DUAL-SPORT
- RIDING STYLE:
- STREET
- TYPE:
- TOP END
- APPLICATION:
- PISTON
- INSIDE DIAMETER METRIC:
- 18 MM
- MATERIAL:
- SILICONE
- PRODUCT NAME:
- BEARING
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- EACH
- RIDING STYLE:
- WATERCRAFT
$25.95 -
WORKS CONNECTION Engine Timing Plug - Blue - Kawasaki 24-543
WORKS CONNECTION
$46.95Engine timing plugs might seem like a minor detail, but they're one of the first things visible when you open the clutch cover—and they set the tone for your entire build's attention to detail. WORKS CONNECTION's precision-machined timing plugs replace...09500196- SKU:
- 09500196
- Availability:
- Ships Same Business Day
- Weight:
- 0.11 LBS
- PRODUCT NAME:
- PLUG
- RIDING STYLE:
- STREET
- TYPE:
- ENGINE
- UNITS:
- SET
- COLOR/FINISH:
- ANODIZED
- COLOR/FINISH:
- BLUE
- MATERIAL:
- 6061 T-6 ALUMINUM
- RIDING STYLE:
- OFF-ROAD
$46.95
