Harley Engine
Harley Bike Engine Parts at JJ Motorsports
Rebuild and boost your Harley's engine with premium parts from JJ Motorsports. Our inventory features complete gasket sets, piston kits, oil filters, pushrod tubes, and coolers designed for maximum strength, leak-free sealing, and high-performance in extreme conditions. Compatible with Big Twins, Softail, Touring, and more, these components support top-end overhauls, oil management, and durability for street rides or custom builds.
Shop trusted brands like Drag Specialties for magnetic filters and Wiseco for forged pistons. Explore related categories such as Harley air and fuel for carb tuning or Harley drivetrain for transmission upgrades.
Top Harley Engine Products
- DRAG SPECIALTIES Magnetic Ring Oil Filter - Chrome - 3-1/4" 140003HP-BX18 – Captures metal particles with pressure relief.
- WISECO Piston Kit .010 .883 XL K1656 – Forged aluminum with rings, pins, and circlips for rebuilds.
- DRAG SPECIALTIES Pushrod Tube Kit Big Twin 75711 – Includes tubes, clips, cups, and springs for complete engine.
- ULTRACOOL Below Regulator Mount Oil Cooler Stainless Steel RF-2CSS – Fits S&S 111/124/143 engines with machined adapter.
- PAUGHCO Ribbed Teardrop Air Cleaner 701-200 – Chrome-plated aluminum with mini filter.
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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COMETIC Sprocket Shaft Seal C9366-1
COMETIC
$6.00Sprocket shaft seals are critical to preventing fluid leakage and contamination in high-performance engines where precision and reliability are non-negotiable. The COMETIC C9366-1 delivers the durability required for sustained racing applications without...09350829- SKU:
- 09350829
- Availability:
- Ships Same Business Day
- Weight:
- 0.10 LBS
- APPLICATION:
- SPROCKET SHAFT
- PRODUCT NAME:
- SEAL
- UNITS:
- EACH
- MATERIAL:
- VITON
- RIDING STYLE:
- STREET
- TYPE:
- OIL
$6.00 -
COMETIC Valve Stem Seal C9424-1
COMETIC
$5.00Valve stem seals are critical components that prevent oil from leaking past the valve guides and into the combustion chamber—a problem that leads to blue smoke, increased oil consumption, and accelerated wear on catalytic converters. The COMETIC C9424-1...09350835- SKU:
- 09350835
- Availability:
- Ships Same Business Day
- Weight:
- 0.11 LBS
- PRODUCT NAME:
- SEAL
- UNITS:
- EACH
- MATERIAL:
- VITON
- OUTSIDE DIAMETER IMPERIAL:
- 0.625'
- TYPE:
- VALVE STEM
- RIDING STYLE:
- STREET
$5.00 -
On Sale
COMETIC Oil Pump Inner Small O-Ring C9449
COMETIC
Now: $7.00Was: $7.40A failing oil pump seal compromises lubrication pressure across your entire engine, risking catastrophic bearing wear and sudden failure. The COMETIC Oil Pump Inner Small O-Ring (C9449) is engineered from premium fuel-resistant elastomer that maintains...09350159- SKU:
- 09350159
- Availability:
- Ships Same Business Day
- Weight:
- 0.11 LBS
- MATERIAL:
- VITON
- PRODUCT NAME:
- O-RING
- APPLICATION:
- OIL PUMP
- RIDING STYLE:
- STREET
- UNITS:
- 10 PACK
Now: $7.00Was: $7.40 -
On Sale
COMETIC Derby Cover O-Ring - Big Twin C9662
COMETIC
Now: $14.00Was: $15.40The COMETIC Derby Cover O-Ring is engineered to prevent oil leakage and maintain proper crankcase sealing on your Big Twin—critical for consistent engine performance and longevity. Built from premium fuel-resistant elastomers, this O-ring resists the...09350160- SKU:
- 09350160
- Availability:
- Ships Same Business Day
- Weight:
- 0.10 LBS
- APPLICATION:
- DERBY COVER
- RIDING STYLE:
- STREET
- PRODUCT NAME:
- O-RING
- UNITS:
- 5 PACK
- MATERIAL:
- NITRILE RUBBER
Now: $14.00Was: $15.40 -
On Sale
COMETIC Umbrella Seal C9481
COMETIC
Now: $8.00Was: $8.40Umbrella seals are critical for preventing oil seepage and maintaining pressure integrity in high-performance engines, especially under sustained boost and elevated operating temperatures. The COMETIC C9481 is engineered with fuel-resistant elastomers...09350167- SKU:
- 09350167
- Availability:
- Ships Same Business Day
- Weight:
- 0.10 LBS
- PRODUCT NAME:
- SEAL
- UNITS:
- 10 PACK
- RIDING STYLE:
- STREET
- MATERIAL:
- VITON
- APPLICATION:
- UMBRELLA VALVE
Now: $8.00Was: $8.40 -
On Sale
COMETIC O-Ring C9459
COMETIC
Now: $3.00Was: $3.20Cometic O-Ring seals are engineered to withstand extreme pressures and temperature fluctuations in high-performance applications where standard gaskets fail. Whether you're building a forced induction engine or restoring a precision machine, this U.S...09350170- SKU:
- 09350170
- Availability:
- Ships Same Business Day
- Weight:
- 0.11 LBS
- APPLICATION:
- DIPSTICK COVER
- RIDING STYLE:
- STREET
- PRODUCT NAME:
- O-RING
- UNITS:
- 25 PACK
- APPLICATION:
- PUSHROD COVER
- MATERIAL:
- NITRILE RUBBER
Now: $3.00Was: $3.20 -
On Sale
COMETIC Carb/Manifold Sealing Ring C9088
COMETIC
MSRP: $10.95Now: $10.00Was: $10.95Carburetor and manifold sealing rings are critical interfaces in your fuel system—a leak or deterioration here compromises air-fuel ratios and can cause fuel seepage into your engine bay. The COMETIC C9088 is engineered to eliminate these failure points...09350173- SKU:
- 09350173
- Availability:
- Ships Same Business Day
- Weight:
- 0.10 LBS
- MATERIAL:
- FIBER
- APPLICATION:
- INTAKE MANIFOLD TO CARBURETOR
- RIDING STYLE:
- STREET
- PRODUCT NAME:
- SEAL
- THICKNESS IMPERIAL:
- 0.031'
- UNITS:
- EACH
MSRP: $10.95Now: $10.00Was: $10.95 -
On Sale
COMETIC Starter Shaft Seal C9379
COMETIC
Now: $14.00Was: $14.80A leaking starter shaft seal compromises engine oil integrity and increases the risk of costly internal damage. The COMETIC C9379 Starter Shaft Seal delivers OEM-quality sealing performance with precise tolerances engineered to prevent oil weeping at the...09350181- SKU:
- 09350181
- Availability:
- Ships Same Business Day
- Weight:
- 0.11 LBS
- PRODUCT NAME:
- SEAL
- APPLICATION:
- STARTER SHAFT
- UNITS:
- 5 PACK
- MATERIAL:
- VITON
- RIDING STYLE:
- STREET
Now: $14.00Was: $14.80 -
On Sale
COMETIC Starter Shaft Seal C9509
COMETIC
Now: $16.00Was: $16.90A failing starter shaft seal compromises engine reliability and creates potential oil leakage at a critical junction. The COMETIC C9509 delivers precision sealing that prevents costly internal damage and maintains optimal engine protection during...09350182- SKU:
- 09350182
- Availability:
- Ships Same Business Day
- Weight:
- 0.25 LBS
- APPLICATION:
- STARTER SHAFT
- UNITS:
- 5 PACK
- PRODUCT NAME:
- SEAL
- MATERIAL:
- DUAL LIP VITON
- RIDING STYLE:
- STREET
Now: $16.00Was: $16.90 -
On Sale
COMETIC Drain Plug Washer C9498
COMETIC
Now: $6.00Was: $6.70A worn or degraded drain plug washer is an often-overlooked source of slow oil leaks that compound maintenance headaches over time. The COMETIC C9498 eliminates this vulnerability with a premium, fuel-resistant compound engineered to maintain a reliable...09350185- SKU:
- 09350185
- Availability:
- Ships Same Business Day
- Weight:
- 0.10 LBS
- MATERIAL:
- NYLON
- RIDING STYLE:
- STREET
- THICKNESS:
- 0,063'
- THICKNESS IMPERIAL:
- 0.063'
- UNITS:
- 10 PACK
- APPLICATION:
- DRAIN PLUG
- PRODUCT NAME:
- WASHER
Now: $6.00Was: $6.70 -
On Sale
COMETIC Counter Shaft O-Ring C9529
COMETIC
Now: $6.00Was: $6.40Counter shaft seals are critical to maintaining proper engine pressurization and preventing fuel leakage in high-performance applications. The COMETIC C9529 O-Ring is engineered from premium, fuel-resistant elastomers that resist the thermal cycling and...09350187- SKU:
- 09350187
- Availability:
- Ships Same Business Day
- Weight:
- 0.11 LBS
- PRODUCT NAME:
- O-RING
- RIDING STYLE:
- STREET
- UNITS:
- 10 PACK
- APPLICATION:
- COUNTERSHAFT
- MATERIAL:
- BUNA RUBBER
Now: $6.00Was: $6.40 -
On Sale
COMETIC Mainshaft Quad Seal C9361
COMETIC
Now: $10.00Was: $10.60Mainshaft seals are critical to preventing internal transmission fluid leakage and maintaining hydraulic pressure—especially under high-performance driving conditions where vibration and heat accelerate seal degradation. The COMETIC Mainshaft Quad Seal...09350189- SKU:
- 09350189
- Availability:
- Ships Same Business Day
- Weight:
- 0.10 LBS
- APPLICATION:
- MAIN DRIVE GEAR
- MATERIAL:
- VITON
- RIDING STYLE:
- STREET
- PRODUCT NAME:
- SEAL
- UNITS:
- 10 PACK
- APPLICATION:
- TRANSMISSION
Now: $10.00Was: $10.60 -
On Sale
COMETIC Filler Plug O-Ring C9263
COMETIC
MSRP: $4.15Now: $4.00Was: $4.20A leaking filler plug can compromise your entire cooling system's integrity and lead to catastrophic engine damage. The COMETIC Filler Plug O-Ring C9263 delivers a reliable, OEM-quality seal that prevents coolant loss and maintains system pressure where...09350191- SKU:
- 09350191
- Availability:
- Ships Same Business Day
- Weight:
- 0.10 LBS
- RIDING STYLE:
- STREET
- UNITS:
- 10 PACK
- MATERIAL:
- VITON
- PRODUCT NAME:
- O-RING
- APPLICATION:
- FILLER PLUG
MSRP: $4.15Now: $4.00Was: $4.20 -
On Sale
COMETIC Head Gasket - .03" - Evo - 3.5" C9688
COMETIC
MSRP: $61.90Now: $58.00Was: $61.90A failed head gasket can mean catastrophic engine damage and costly downtime—especially on a high-compression Evo platform. The COMETIC C9688 uses multi-layer steel construction with load control embossments to distribute clamping force evenly across the...DS172086- SKU:
- DS172086
- Availability:
- Ships Same Business Day
- Weight:
- 0.19 LBS
- MATERIAL:
- LAYERED STEEL
- THICKNESS IMPERIAL:
- 0,030'
- BORE SIZE:
- 3,500'
- BORE SIZE IMPERIAL:
- 3.500'
- PRODUCT NAME:
- GASKET
- THICKNESS METRIC:
- 0.76 MM
- TYPE:
- CYLINDER HEAD
- UNITS:
- PAIR
- RIDING STYLE:
- STREET
- THICKNESS:
- 0,76 MM (0,030')
MSRP: $61.90Now: $58.00Was: $61.90 -
On Sale
COMETIC Head Gasket - .03"- Evo - 3.625" C9690
COMETIC
MSRP: $61.90Now: $58.00Was: $61.90A head gasket is your engine's critical seal—any compromise in material or design directly impacts compression, power output, and longevity. The COMETIC C9690 uses multi-layer steel construction with load control embossments to distribute clamping force...DS172088- SKU:
- DS172088
- Availability:
- Ships Same Business Day
- Weight:
- 0.94 LBS
- BORE SIZE IMPERIAL:
- 3.670'
- MATERIAL:
- LAYERED STEEL
- THICKNESS:
- 0,76 MM (0,030')
- THICKNESS IMPERIAL:
- 0,030'
- THICKNESS METRIC:
- 0.76 MM
- PRODUCT NAME:
- GASKET
- TYPE:
- CYLINDER HEAD
- RIDING STYLE:
- STREET
- UNITS:
- PAIR
- BORE SIZE:
- 3,670'
MSRP: $61.90Now: $58.00Was: $61.90 -
On Sale
COMETIC Head Gasket - .030" - 95" - Twin Cam C9721
COMETIC
MSRP: $61.90Now: $58.00Was: $61.90A properly sealed combustion chamber is non-negotiable for engine reliability and power output—especially in high-performance Twin Cam applications where heat cycling and boost pressure demand precision. The COMETIC C9721 head gasket uses multi-layer...DS172104- SKU:
- DS172104
- Availability:
- Ships Same Business Day
- Weight:
- 0.20 LBS
- BORE SIZE:
- 3,875'
- PRODUCT NAME:
- GASKET
- MATERIAL:
- LAYERED STEEL
- THICKNESS:
- 0,76 MM (0,030')
- THICKNESS IMPERIAL:
- 0,030'
- BORE SIZE IMPERIAL:
- 3.875'
- TYPE:
- CYLINDER HEAD
- RIDING STYLE:
- STREET
- THICKNESS METRIC:
- 0.76 MM
- UNITS:
- PAIR
MSRP: $61.90Now: $58.00Was: $61.90 -
On Sale
COMETIC Head Gasket - .030" - 88" - Twin Cam C9790
COMETIC
MSRP: $61.90Now: $58.00Was: $61.90A quality head gasket is fundamental to engine reliability and performance—it's the barrier between combustion pressure and coolant passages, so compromise here means potential catastrophic failure. The COMETIC C9790 uses multi-layer steel construction...DS172106- SKU:
- DS172106
- Availability:
- Ships Same Business Day
- Weight:
- 0.20 LBS
- RIDING STYLE:
- STREET
- PRODUCT NAME:
- GASKET
- TYPE:
- CYLINDER HEAD
- UNITS:
- PAIR
- BORE SIZE IMPERIAL:
- 3.750'
- MATERIAL:
- LAYERED STEEL
- THICKNESS IMPERIAL:
- 0,030'
- THICKNESS METRIC:
- 0.76 MM
- BORE SIZE:
- 3,750'
- THICKNESS:
- 0,76 MM (0,030')
MSRP: $61.90Now: $58.00Was: $61.90 -
On Sale
COMETIC Upper Tappet Block O-Ring C9443
COMETIC
Now: $8.00Was: $8.40The upper tappet block o-ring is a critical seal in your engine's valve train system—when it fails, oil leakage and compromised cylinder head pressure follow immediately. Cometic's C9443 is engineered from premium fuel-resistant elastomers that maintain...09350226- SKU:
- 09350226
- Availability:
- Ships Same Business Day
- Weight:
- 0.11 LBS
- MATERIAL:
- VITON
- APPLICATION:
- UPPER TAPPET BLOCK
- UNITS:
- 10 PACK
- RIDING STYLE:
- STREET
- PRODUCT NAME:
- O-RING
Now: $8.00Was: $8.40 -
COMETIC Tappet Pin Cover O-Ring C9296
COMETIC
$4.00A failing tappet pin cover O-ring will compromise your engine's seal integrity and lead to oil leakage that degrades performance and creates messy maintenance headaches. The COMETIC C9296 delivers the reliability you need with a precision-engineered seal...09350229- SKU:
- 09350229
- Availability:
- Ships Same Business Day
- Weight:
- 0.11 LBS
- RIDING STYLE:
- STREET
- APPLICATION:
- TAPPET COVER
- MATERIAL:
- NITRILE
- UNITS:
- 10 PACK
- PRODUCT NAME:
- O-RING
$4.00 -
On Sale
COMETIC Starter Gasket - AFM C9312F
COMETIC
Now: $6.00Was: $6.10A failing starter gasket compromises your engine's seal integrity and can lead to costly oil leaks and starter failure. The COMETIC C9312F is engineered to deliver a reliable, long-lasting seal that withstands repeated thermal cycles and engine vibration...09350238- SKU:
- 09350238
- Availability:
- Ships Same Business Day
- Weight:
- 0.10 LBS
- MATERIAL:
- AFM (ALUMINUM FOAM MATERIAL)
- PRODUCT NAME:
- GASKET
- UNITS:
- 10 PACK
- THICKNESS:
- 0,032'
- TYPE:
- MOTOR
- TYPE:
- STARTER
- THICKNESS IMPERIAL:
- 0.032'
- RIDING STYLE:
- STREET
Now: $6.00Was: $6.10
