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
-
BOYESEN Ignition Cover - Gold - CR250 SC-02M
BOYESEN
$87.95Look like a professional with the Factory Ignition Cover, Seals properly, guarding inside of engine from dirt and water and outlasts stock covers, Boyesen Factory Covers are cast from the highest grade of aluminum and are strong yet lightweight,...09400210- SKU:
- 09400210
- Availability:
- Ships Same Business Day
- Weight:
- 0.60 LBS
- COLOR/FINISH:
- MAGNESIUM
- COLOR/FINISH:
- POWDER-COATED
- MATERIAL:
- ALUMINUM
- PRODUCT NAME:
- COVER
- MODEL:
- FACTORY RACING
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- IGNITION
- UNITS:
- EACH
$87.95Qty in Cart: 0Quantity:Price:$87.95Subtotal: -
BOYESEN Ignition Gasket Cover - KTM SCG-40A
BOYESEN
$5.95Look like a professional with the Factory Ignition Cover, Seals properly, guarding inside of engine from dirt and water and outlasts stock covers, Boyesen Factory Covers are cast from the highest grade of aluminum and are strong yet lightweight,...09343123- SKU:
- 09343123
- Availability:
- Ships Same Business Day
- Weight:
- 0.05 LBS
- TYPE:
- IGNITION COVER
- PRODUCT NAME:
- GASKET
- RIDING STYLE:
- OFF-ROAD
- MATERIAL:
- NITRILE RUBBER
- MODEL:
- FACTORY RACING
- UNITS:
- EACH
$5.95Qty in Cart: 0Quantity:Price:$5.95Subtotal: -
BOYESEN Impeller/Waterpump Cover - Orange WPK-44AO
BOYESEN
$199.95An aluminum investment-cast water pump cover and impeller combo; specifically designed to enhance the performance of your engines cooling system, This high-flow, hydrodynamic water pump kit has been tested and designed to flow more coolant, By increasing...09320156- SKU:
- 09320156
- Availability:
- Ships Same Business Day
- Weight:
- 0.35 LBS
- BASE FINISH:
- POWDER-COATED
- COLOR/FINISH:
- POWDER-COATED
- TYPE:
- WATER PUMP
- COLOR/FINISH:
- ORANGE
- MODEL:
- SUPERCOOLER
- PRODUCT NAME:
- COVER AND IMPELLER KIT
- UNITS:
- KIT
- MATERIAL:
- ALUMINUM
- BASE COLOR:
- ORANGE
- RIDING STYLE:
- OFF-ROAD
$199.95Qty in Cart: 0Quantity:Price:$199.95Subtotal: -
On Sale
HOT RODS Seal Output Shaft OSK0039
HOT RODS
MSRP: $35.95Now: $32.36Was: $35.95A quick solution to repairing a leaking countershaft seal in one complete kit, Includes Hot Rods countershaft seal, countershaft bushing, O-rings, and sprocket nut washer (where applicable), Kits do not include water pump bearing or transmission bearings.09350561- SKU:
- 09350561
- Availability:
- Ships Same Business Day
- Weight:
- 0.15 LBS
- PRODUCT NAME:
- SEAL
- APPLICATION:
- COUNTERSHAFT
- APPLICATION:
- TRANSMISSION
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
MSRP: $35.95Now: $32.36Was: $35.95Qty in Cart: 0Quantity:Price:MSRP: $35.95Now: $32.36Was: $35.95Subtotal: -
On Sale
HOT RODS Seal Output Shaft OSK0048
HOT RODS
MSRP: $13.95Now: $12.56Was: $13.95A quick solution to repairing a leaking countershaft seal in one complete kit, Includes Hot Rods countershaft seal, countershaft bushing, O-rings, and sprocket nut washer (where applicable), Kits do not include water pump bearing or transmission bearings.09350563- SKU:
- 09350563
- Availability:
- Ships Same Business Day
- Weight:
- 0.10 LBS
- PRODUCT NAME:
- SEAL
- APPLICATION:
- COUNTERSHAFT
- APPLICATION:
- TRANSMISSION
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
MSRP: $13.95Now: $12.56Was: $13.95 -
On Sale
HOT RODS Seal Output Shaft OSK0051
HOT RODS
MSRP: $26.95Now: $24.26Was: $26.95A quick solution to repairing a leaking countershaft seal in one complete kit, Includes Hot Rods countershaft seal, countershaft bushing, O-rings, and sprocket nut washer (where applicable), Kits do not include water pump bearing or transmission bearings.09350566- SKU:
- 09350566
- Availability:
- Ships Same Business Day
- Weight:
- 0.10 LBS
- APPLICATION:
- COUNTERSHAFT
- APPLICATION:
- TRANSMISSION
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- PRODUCT NAME:
- SEAL
MSRP: $26.95Now: $24.26Was: $26.95Qty in Cart: 0Quantity:Price:MSRP: $26.95Now: $24.26Was: $26.95Subtotal: -
On Sale
HOT RODS Seal Output Shaft OSK0053
HOT RODS
MSRP: $35.95Now: $32.36Was: $35.95A quick solution to repairing a leaking countershaft seal in one complete kit, Includes Hot Rods countershaft seal, countershaft bushing, O-rings, and sprocket nut washer (where applicable), Kits do not include water pump bearing or transmission bearings.09350568- SKU:
- 09350568
- Availability:
- Ships Same Business Day
- Weight:
- 0.15 LBS
- APPLICATION:
- COUNTERSHAFT
- PRODUCT NAME:
- SEAL
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- APPLICATION:
- TRANSMISSION
MSRP: $35.95Now: $32.36Was: $35.95 -
On Sale
HOT RODS Seal Output Shaft OSK0002
HOT RODS
MSRP: $37.95Now: $34.16Was: $37.95A quick solution to repairing a leaking countershaft seal in one complete kit, Includes Hot Rods countershaft seal, countershaft bushing, O-rings, and sprocket nut washer (where applicable), Kits do not include water pump bearing or transmission bearings.09350569- SKU:
- 09350569
- Availability:
- Ships Same Business Day
- Weight:
- 0.15 LBS
- APPLICATION:
- COUNTERSHAFT
- APPLICATION:
- TRANSMISSION
- RIDING STYLE:
- OFF-ROAD
- PRODUCT NAME:
- SEAL
- UNITS:
- KIT
MSRP: $37.95Now: $34.16Was: $37.95Qty in Cart: 0Quantity:Price:MSRP: $37.95Now: $34.16Was: $37.95Subtotal: -
On Sale
HOT RODS Seal Output Shaft OSK0004
HOT RODS
MSRP: $31.95Now: $28.76Was: $31.95A quick solution to repairing a leaking countershaft seal in one complete kit, Includes Hot Rods countershaft seal, countershaft bushing, O-rings, and sprocket nut washer (where applicable), Kits do not include water pump bearing or transmission bearings.09350571- SKU:
- 09350571
- Availability:
- Ships Same Business Day
- Weight:
- 0.15 LBS
- APPLICATION:
- COUNTERSHAFT
- APPLICATION:
- TRANSMISSION
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- PRODUCT NAME:
- SEAL
MSRP: $31.95Now: $28.76Was: $31.95 -
On Sale
HOT RODS Seal Output Shaft OSK0006
HOT RODS
MSRP: $13.95Now: $12.56Was: $13.95A quick solution to repairing a leaking countershaft seal in one complete kit, Includes Hot Rods countershaft seal, countershaft bushing, O-rings, and sprocket nut washer (where applicable), Kits do not include water pump bearing or transmission bearings.09350572- SKU:
- 09350572
- Availability:
- Ships Same Business Day
- Weight:
- 0.10 LBS
- UNITS:
- KIT
- RIDING STYLE:
- OFF-ROAD
- APPLICATION:
- COUNTERSHAFT
- APPLICATION:
- TRANSMISSION
- PRODUCT NAME:
- SEAL
MSRP: $13.95Now: $12.56Was: $13.95 -
On Sale
HOT RODS Connecting Rod 8725
HOT RODS
MSRP: $151.95Now: $136.76Was: $151.95Heavy-duty OE replacement connecting rods, Certified 8620 AISI steel provides superior strength, Crankpins are manufactured from hot-rolled ASTM 4115 and case hardened to 58-62Rc, Feature the latest in caged needle roller bearing designs for high rpm...09230516- SKU:
- 09230516
- Availability:
- Ships Same Business Day
- Weight:
- 0.50 LBS
- MATERIAL:
- 8620 STEEL
- PRODUCT NAME:
- CONNECTING ROD KIT
- RIDING STYLE:
- OFF-ROAD
- ENGINE TYPE:
- 2-CYCLE
- FEATURES:
- INCLUDES THRUST WASHERS
- UNITS:
- KIT
MSRP: $151.95Now: $136.76Was: $151.95 -
On Sale
HOT RODS Crank Bearings K072
HOT RODS
MSRP: $89.95Now: $80.96Was: $89.95Precision, high-quality main bearing and seal kits complement installation of Hot Rods crankshaft assemblies09240247- SKU:
- 09240247
- Availability:
- Ships Same Business Day
- Weight:
- 1.51 LBS
- APPLICATION:
- MAIN CRANKSHAFT
- PRODUCT NAME:
- BEARING
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- TYPE:
- BALL
MSRP: $89.95Now: $80.96Was: $89.95Qty in Cart: 0Quantity:Price:MSRP: $89.95Now: $80.96Was: $89.95Subtotal: -
On Sale
HOT RODS Crankshaft Kit CBK0001
HOT RODS
MSRP: $305.95Now: $275.36Was: $305.95Assembly sold complete with Hot Rods connecting rod, Factory assembled and true to OEM specifications, Hot Rods cranks will meet or surpass the OEM in performance, Ready for installation, Crankshaft is completely rebuildable with genuine Hot Rods...09210260- SKU:
- 09210260
- Availability:
- Ships Same Business Day
- Weight:
- 7.10 LBS
- TYPE:
- OEM
- PRODUCT NAME:
- CRANKSHAFT KIT
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
MSRP: $305.95Now: $275.36Was: $305.95 -
On Sale
HOT RODS Crankshaft Kit CBK0004
HOT RODS
MSRP: $741.95Now: $667.76Was: $741.95Assembly sold complete with Hot Rods connecting rod, Factory assembled and true to OEM specifications, Hot Rods cranks will meet or surpass the OEM in performance, Ready for installation, Crankshaft is completely rebuildable with genuine Hot Rods...09210263- SKU:
- 09210263
- Availability:
- Ships Same Business Day
- Weight:
- 9.47 LBS
- TYPE:
- OEM
- RIDING STYLE:
- OFF-ROAD
- PRODUCT NAME:
- CRANKSHAFT KIT
- UNITS:
- KIT
MSRP: $741.95Now: $667.76Was: $741.95Qty in Cart: 0Quantity:Price:MSRP: $741.95Now: $667.76Was: $741.95Subtotal: -
On Sale
HOT RODS Crankshaft Kit CBK0006
HOT RODS
MSRP: $795.95Now: $716.36Was: $795.95Assembly sold complete with Hot Rods connecting rod, Factory assembled and true to OEM specifications, Hot Rods cranks will meet or surpass the OEM in performance, Ready for installation, Crankshaft is completely rebuildable with genuine Hot Rods...09210265- SKU:
- 09210265
- Availability:
- Ships Same Business Day
- Weight:
- 12.35 LBS
- PRODUCT NAME:
- CRANKSHAFT KIT
- TYPE:
- OEM
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
MSRP: $795.95Now: $716.36Was: $795.95 -
On Sale
COMETIC Exhaust Gasket - Honda C7126EX
COMETIC
MSRP: $11.95Now: $11.00Was: $11.95Gasket material and construction will vary by application to ensure longevity with leak free performance under all conditions, 4-stroke applications utilize a double-sided Viton® rubber-coated stainless steel gasket providing precise, high-temperature...09344236- SKU:
- 09344236
- Availability:
- Ships Same Business Day
- Weight:
- 0.02 LBS
- BORE SIZE METRIC:
- 51.00 MM
- RIDING STYLE:
- OFF-ROAD
- PRODUCT NAME:
- GASKET
- MODEL:
- HI-PERFORMANCE
- TYPE:
- EXHAUST
- UNITS:
- SET
MSRP: $11.95Now: $11.00Was: $11.95 -
On Sale
COMETIC Bottom End Gasket Set - Honda C7191BE
COMETIC
MSRP: $82.95Now: $78.00Was: $82.95Bottom end gasket kits include correct oil seals, O-rings, drain plug washers and water pump cover gaskets as needed, Materials will vary depending on what is correct and engineered for specified application, Purchase a top and a bottom end gasket kit...09344252- SKU:
- 09344252
- Availability:
- Ships Same Business Day
- Weight:
- 0.15 LBS
- BORE SIZE METRIC:
- 68.50 MM
- PRODUCT NAME:
- GASKET KIT
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- BOTTOM END
- BORE SIZE METRIC:
- 66.50 MM
- MODEL:
- HI-PERFORMANCE
- UNITS:
- KIT
MSRP: $82.95Now: $78.00Was: $82.95Qty in Cart: 0Quantity:Price:MSRP: $82.95Now: $78.00Was: $82.95Subtotal: -
On Sale
COMETIC Stator Gasket - Suzuki EC1019032AFM
COMETIC
MSRP: $13.95Now: $13.00Was: $13.95Stator cover gaskets are made from an AFM Material which is a chemically blown, compounded nitrile synthetic rubber bonded to an aluminum core, Save service time as AFM will not stick to the engine case making replacement quick and easy, no more...09344363- SKU:
- 09344363
- Availability:
- Ships Same Business Day
- Weight:
- 0.05 LBS
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- STATOR COVER
- MODEL:
- HI-PERFORMANCE
- MATERIAL:
- AFM (ALUMINUM FOAM MATERIAL)
- PRODUCT NAME:
- GASKET
- UNITS:
- EACH
MSRP: $13.95Now: $13.00Was: $13.95 -
On Sale
Hot Cams Stage 2 Intake Camshaft for Suzuki RM-Z 450 2008-2014 2268-2IN
HOT CAMS
MSRP: $263.95Now: $169.00Was: $263.95Elevate your engine's performance with the HOT CAMS 2268-2IN camshaft, expertly engineered for high-performance racing applications. Designed for seamless installation with stock valve springs, this camshaft optimizes both torque and horsepower, ensuring...09250868- SKU:
- 09250868
- Availability:
- Ships Same Business Day
- Weight:
- 0.55 LBS
- INTAKE LIFT METRIC:
- 9.90 MM
- INTAKE DURATION IMPERIAL:
- 246.5°
- UNITS:
- EACH
- PRODUCT NAME:
- CAMSHAFT
- APPLICATION:
- INTAKE
- RIDING STYLE:
- OFF-ROAD
MSRP: $263.95Now: $169.00Was: $263.95Qty in Cart: 0Quantity:Price:MSRP: $263.95Now: $169.00Was: $263.95Subtotal: -
Hot Cams Stage 1 Intake Camshaft for 2014-2015 Yamaha YZ450F 4278-1IN
HOT CAMS
$289.95Elevate your racing performance with the HOT CAMS Camshaft 4278-1IN, engineered for enthusiasts seeking both reliability and power. This camshaft is designed to seamlessly integrate with stock valve springs, making it an ideal choice for those looking to...09250882- SKU:
- 09250882
- Availability:
- Ships Same Business Day
- Weight:
- 0.96 LBS
- APPLICATION:
- INTAKE
- RIDING STYLE:
- OFF-ROAD
- INTAKE DURATION IMPERIAL:
- 251.8°
- UNITS:
- EACH
- PRODUCT NAME:
- CAMSHAFT
- INTAKE LIFT METRIC:
- 9.73 MM
$289.95Qty in Cart: 0Quantity:Price:$289.95Subtotal:
