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
-
COMETIC Trans Gasket - FXD C9151
COMETIC
$75.55Transmission gasket failure compromises your driveline's integrity and leads to costly fluid leaks and contamination. The COMETIC Trans Gasket C9151 delivers application-specific engineering with...09341211- SKU:
- 09341211
- Availability:
- Ships Same Business Day
- Weight:
- 0.37 LBS
- UNITS:
- KIT
- PRODUCT NAME:
- GASKET KIT
- RIDING STYLE:
- STREET
- TYPE:
- TRANSMISSION
$75.55 -
COMETIC Head Gasket - .051" - MLS Standard C9157
COMETIC
$61.90A head gasket failure can sideline your engine and drain your wallet—this COMETIC MLS gasket eliminates that risk with proven multi-layer steel construction that handles high boost pressures, varying...09341213- SKU:
- 09341213
- Availability:
- Ships Same Business Day
- Weight:
- 0.32 LBS
- BORE SIZE:
- 3,750'
- MATERIAL:
- LAYERED STEEL
- BORE SIZE IMPERIAL:
- 3.750'
- RIDING STYLE:
- STREET
- THICKNESS IMPERIAL:
- 0,051'
- TYPE:
- CYLINDER HEAD
- PRODUCT NAME:
- GASKET
- THICKNESS METRIC:
- 1.29 MM
- UNITS:
- PAIR
- MATERIAL:
- VITON
- THICKNESS:
- 1,29 MM (0,051')
$61.90 -
COMETIC Trans Bearing Gasket - Twin Cam C9187
COMETIC
$20.60Transmission bearing gaskets are critical sealing components that prevent fluid leakage and maintain pressure integrity in your drivetrain. A failed or degraded gasket compromises transmission...09341232- SKU:
- 09341232
- Availability:
- Ships Same Business Day
- Weight:
- 0.20 LBS
- RIDING STYLE:
- STREET
- THICKNESS IMPERIAL:
- 0,032'
- THICKNESS METRIC:
- 0.81 MM
- TYPE:
- BEARING HOUSING
- MATERIAL:
- AFM (ALUMINUM FOAM MATERIAL)
- PRODUCT NAME:
- GASKET
- THICKNESS:
- 0,81 MM (0,032')
- UNITS:
- 10 PACK
$20.60Qty in Cart: 0Quantity:Price:$20.60Subtotal: -
COMETIC Complete Gasket Kit - FLT/FXR - 5 Speed C9750F
COMETIC
$356.95A complete gasket failure can sideline your bike and drain your wallet. COMETIC's FLT/FXR kit eliminates guesswork by providing factory-engineered gaskets for every critical seal—head, base, valve...09340729- SKU:
- 09340729
- Availability:
- Ships Same Business Day
- Weight:
- 1.95 LBS
- BORE SIZE IMPERIAL:
- 3.500'
- UNITS:
- KIT
- MATERIAL:
- STEEL
- MATERIAL:
- VITON
- TYPE:
- COMPLETE
- BORE SIZE:
- 3,500'
- MATERIAL:
- AFM (ALUMINUM FOAM MATERIAL)
- PRODUCT NAME:
- GASKET KIT
- RIDING STYLE:
- STREET
- THICKNESS IMPERIAL:
- 0,040'
- THICKNESS METRIC:
- 1.02 MM
$356.95 -
COMETIC Complete Gasket Kit - ST/FXD C9777F
COMETIC
$287.65A complete gasket failure can sideline your engine and cost you races or valuable track time. The COMETIC Complete Gasket Kit C9777F eliminates guesswork by providing every critical gasket you...09340731- SKU:
- 09340731
- Availability:
- Ships Same Business Day
- Weight:
- 1.80 LBS
- MATERIAL:
- VITON
- RIDING STYLE:
- STREET
- MATERIAL:
- AFM (ALUMINUM FOAM MATERIAL)
- PRODUCT NAME:
- GASKET KIT
- BORE SIZE:
- STANDARD
- BORE SIZE IMPERIAL:
- STANDARD
- MATERIAL:
- STEEL
- TYPE:
- COMPLETE
- UNITS:
- KIT
$287.65Qty in Cart: 0Quantity:Price:$287.65Subtotal: -
COMETIC Motor Gasket Kit - XL C9952
COMETIC
$202.60A complete gasket kit is non-negotiable for any serious engine rebuild or performance upgrade. COMETIC's XL C9952 kit delivers OEM-quality sealing across your entire engine using purpose-built...09340736- SKU:
- 09340736
- Availability:
- Ships Same Business Day
- Weight:
- 1.85 LBS
- PRODUCT NAME:
- GASKET KIT
- THICKNESS IMPERIAL:
- 0,040'
- THICKNESS METRIC:
- 1.02 MM
- RIDING STYLE:
- STREET
- BORE SIZE IMPERIAL:
- 3.500'
- MATERIAL:
- STEEL
- MATERIAL:
- VITON
- TYPE:
- COMPLETE
- UNITS:
- KIT
- BORE SIZE:
- 3,500'
- MATERIAL:
- AFM (ALUMINUM FOAM MATERIAL)
$202.60 -
COMETIC Valve Stem Seal - Viton C9836
COMETIC
$36.80Valve stem seals are critical to preventing oil leakage into your combustion chamber—a problem that causes rough idle, increased emissions, and accelerated wear on your valvetrain. The COMETIC Viton...09340738- SKU:
- 09340738
- Availability:
- Ships Same Business Day
- Weight:
- 0.11 LBS
- UNITS:
- 25 PACK
- PRODUCT NAME:
- SEAL
- RIDING STYLE:
- STREET
- MATERIAL:
- VITON
- TYPE:
- VALVE STEM
$36.80 -
COMETIC Top End Gasket - 3-3/4" - Big Twin C9771
COMETIC
$142.75Top-end gasket failure can sideline your engine when you need it most. The COMETIC C9771 uses Extreme Sealing Technology (EST) to eliminate hot spots that typically cause premature gasket breakdown,...09340756- SKU:
- 09340756
- Availability:
- Ships Same Business Day
- Weight:
- 0.78 LBS
- BORE SIZE IMPERIAL:
- 3.750'
- RIDING STYLE:
- STREET
- TYPE:
- TOP END
- BORE SIZE:
- 3,750'
- ENGINE TYPE:
- 4-STROKE
- MATERIAL:
- RUBBER
- MATERIAL:
- STAINLESS STEEL
- PRODUCT NAME:
- GASKET KIT
- UNITS:
- KIT
$142.75Qty in Cart: 0Quantity:Price:$142.75Subtotal: -
COMETIC Top End Gasket - 1200 XL C9971
COMETIC
$142.75A failing top-end gasket kit doesn't just leak—it compromises combustion efficiency and invites catastrophic engine damage. The COMETIC C9971 uses Extreme Sealing Technology with embossed stainless...09340761- SKU:
- 09340761
- Availability:
- Ships Same Business Day
- Weight:
- 0.90 LBS
- ENGINE TYPE:
- 4-STROKE
- MATERIAL:
- RUBBER
- UNITS:
- KIT
- BORE SIZE:
- 3,500'
- BORE SIZE IMPERIAL:
- 3.500'
- PRODUCT NAME:
- GASKET KIT
- DISPLACEMENT:
- 1200 CC
- RIDING STYLE:
- STREET
- THICKNESS METRIC:
- 0.76 MM
- MATERIAL:
- STAINLESS STEEL
- THICKNESS IMPERIAL:
- 0,030'
- TYPE:
- TOP END
$142.75Qty in Cart: 0Quantity:Price:$142.75Subtotal: -
COMETIC Top End Gasket - .030" C9844
COMETIC
$150.10A top-end rebuild demands precision gaskets that won't fail under heat and pressure—Cometic's EST technology delivers exactly that. This .030" kit eliminates hot spots by dispersing combustion heat...09340762- SKU:
- 09340762
- Availability:
- Ships Same Business Day
- Weight:
- 0.78 LBS
- MATERIAL:
- RUBBER
- UNITS:
- KIT
- BORE SIZE:
- 3,875'
- MATERIAL:
- STAINLESS STEEL
- THICKNESS IMPERIAL:
- 0,030'
- THICKNESS METRIC:
- 0.76 MM
- TYPE:
- TOP END
- RIDING STYLE:
- STREET
- BORE SIZE IMPERIAL:
- 3.875'
- DISPLACEMENT:
- 95'
- ENGINE TYPE:
- 4-STROKE
- PRODUCT NAME:
- GASKET KIT
$150.10 -
COMETIC Top End Gasket - 3-3/4" C9770
COMETIC
$144.85A top-end rebuild demands precision gaskets that won't fail under combustion pressures and extreme temperatures. COMETIC's EST (Extreme Sealing Technology) gaskets use embossed stainless steel...09340765- SKU:
- 09340765
- Availability:
- Ships Same Business Day
- Weight:
- 0.85 LBS
- ENGINE TYPE:
- 4-STROKE
- MATERIAL:
- STAINLESS STEEL
- PRODUCT NAME:
- GASKET KIT
- MATERIAL:
- RUBBER
- UNITS:
- KIT
- BORE SIZE IMPERIAL:
- 3.750'
- TYPE:
- TOP END
- BORE SIZE:
- 3,750'
- RIDING STYLE:
- STREET
$144.85Qty in Cart: 0Quantity:Price:$144.85Subtotal: -
COMETIC Top End Gasket - 3-5/8" C9918
COMETIC
$135.40A failed top end gasket doesn't just leak—it compromises combustion efficiency and can lead to catastrophic engine damage if left unchecked. The COMETIC C9918 EST gasket kit eliminates the guesswork...09340766- SKU:
- 09340766
- Availability:
- Ships Same Business Day
- Weight:
- 0.78 LBS
- BORE SIZE:
- 3,625'
- ENGINE TYPE:
- 4-STROKE
- MATERIAL:
- STEEL
- PRODUCT NAME:
- GASKET KIT
- BORE SIZE IMPERIAL:
- 3.625'
- MATERIAL:
- FOAM
- RIDING STYLE:
- STREET
- MATERIAL:
- ALUMINUM
- MATERIAL:
- VITON
- TYPE:
- TOP END
- UNITS:
- KIT
$135.40 -
COMETIC Top End Gasket - 883 XL C9759
COMETIC
$142.75A failed top-end gasket doesn't just leak—it compromises combustion efficiency and can lead to catastrophic engine damage. The COMETIC C9759 uses Extreme Sealing Technology (EST) to eliminate hot...09340769- SKU:
- 09340769
- Availability:
- Ships Same Business Day
- Weight:
- 0.82 LBS
- BORE SIZE IMPERIAL:
- 3.000'
- RIDING STYLE:
- STREET
- DISPLACEMENT:
- 883 CC
- MATERIAL:
- STAINLESS STEEL
- THICKNESS IMPERIAL:
- 0,040'
- TYPE:
- TOP END
- MATERIAL:
- RUBBER
- UNITS:
- KIT
- BORE SIZE:
- 3,000'
- ENGINE TYPE:
- 4-STROKE
- PRODUCT NAME:
- GASKET KIT
- THICKNESS METRIC:
- 1.02 MM
$142.75Qty in Cart: 0Quantity:Price:$142.75Subtotal: -
COMETIC O-Ring C10208
COMETIC
$9.00Proper sealing is non-negotiable in high-performance applications, and the COMETIC O-Ring C10208 delivers the precision fit your engine demands. Whether you're rebuilding a race engine or maintaining...09350997- SKU:
- 09350997
- Availability:
- Ships Same Business Day
- Weight:
- 0.06 LBS
- APPLICATION:
- CRANKCASE
- PRODUCT NAME:
- O-RING
- RIDING STYLE:
- STREET
- UNITS:
- 10 PACK
$9.00 -
COMETIC Head Gasket - .043" C9239
COMETIC
$56.65A head gasket failure can mean catastrophic engine damage—and the COMETIC C9239 is engineered to prevent that. This multi-layer steel gasket distributes clamping load evenly across the sealing...09350397- SKU:
- 09350397
- Availability:
- Ships Same Business Day
- Weight:
- 0.10 LBS
- MATERIAL:
- CFM
- PRODUCT NAME:
- GASKET
- THICKNESS IMPERIAL:
- 0.043'
- UNITS:
- PAIR
- RIDING STYLE:
- STREET
- THICKNESS:
- 0,043'
- TYPE:
- CYLINDER HEAD
$56.65 -
COMETIC Starter O-Ring - Big Twin C9433F1
COMETIC
$4.95A failing starter O-ring can leave you stranded, and OEM replacements often degrade under heat and fuel exposure. The COMETIC Starter O-Ring for Big Twin engines eliminates this weak point with a...09350850- SKU:
- 09350850
- Availability:
- Ships Same Business Day
- Weight:
- 0.10 LBS
- APPLICATION:
- STARTER HOUSING
- UNITS:
- EACH
- MATERIAL:
- BUNA RUBBER
- PRODUCT NAME:
- O-RING
- RIDING STYLE:
- STREET
$4.95Qty in Cart: 0Quantity:Price:$4.95Subtotal: -
COMETIC Line Sleeve Oil Seal C9365
COMETIC
$7.20Oil seals are critical barriers that prevent fluid loss and contamination in high-performance engines—a single failure can compromise your entire drivetrain. The COMETIC Line Sleeve Oil Seal C9365 is...09350828- SKU:
- 09350828
- Availability:
- Ships Same Business Day
- Weight:
- 0.10 LBS
- MATERIAL:
- VITON
- RIDING STYLE:
- STREET
- APPLICATION:
- OIL LINE
- PRODUCT NAME:
- SEAL
- UNITS:
- 10 PACK
$7.20 -
COMETIC Clutch Gear Seal C9368-1
COMETIC
$5.95Clutch gear seals are a critical point of failure in high-performance engines—improper sealing leads to fluid weepage, contamination, and premature clutch wear. The COMETIC C9368-1 is engineered to...09350831- SKU:
- 09350831
- Availability:
- Ships Same Business Day
- Weight:
- 0.15 LBS
- PRODUCT NAME:
- SEAL
- UNITS:
- EACH
- RIDING STYLE:
- STREET
- TYPE:
- OIL
- APPLICATION:
- CLUTCH GEAR
- MATERIAL:
- VITON
$5.95Qty in Cart: 0Quantity:Price:$5.95Subtotal: -
COMETIC Clutch Hub Seal C9371-1
COMETIC
$6.95Clutch hub seals are critical to maintaining hydraulic integrity in your clutch system—a failure here means fluid loss, air intrusion, and immediate loss of clutch actuation. The COMETIC C9371-1...09350834- SKU:
- 09350834
- Availability:
- Ships Same Business Day
- Weight:
- 0.10 LBS
- APPLICATION:
- CLUTCH HUB
- PRODUCT NAME:
- SEAL
- UNITS:
- EACH
- INSIDE DIAMETER METRIC:
- 33 MM
- RIDING STYLE:
- STREET
- MATERIAL:
- VITON
- OUTSIDE DIAMETER METRIC:
- 47 MM
- THICKNESS METRIC:
- 7 MM
$6.95 -
COMETIC Engine Crankcase Seal C9682
COMETIC
$49.20Engine crankcase seals are critical to preventing oil seepage that compromises performance and creates maintenance headaches. The COMETIC C9682 delivers reliable, long-term sealing without...09350374- SKU:
- 09350374
- Availability:
- Ships Same Business Day
- Weight:
- 0.75 LBS
- RIDING STYLE:
- STREET
- APPLICATION:
- CRANKCASE
- MATERIAL:
- VITON
- UNITS:
- 10 PACK
- PRODUCT NAME:
- SEAL
$49.20
