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
-
On Sale
COMETIC Cam Cover Gasket - XL C9311F5
COMETIC
Now: $48.15Was: $53.50A failing cam cover gasket can silently sabotage your engine—leaking oil onto hot components, creating fire hazards, and compromising internal cleanliness. The COMETIC Cam Cover Gasket XL C9311F5...20111501- SKU:
- 20111501
- Availability:
- Ships Same Business Day
- Weight:
- 0.25 LBS
- UNITS:
- 5 PACK
- RIDING STYLE:
- STREET
- THICKNESS METRIC:
- 1.52 MM
- THICKNESS:
- 1,52 MM (0,060')
- THICKNESS IMPERIAL:
- 0.060'
- MATERIAL:
- AFM (ALUMINUM FOAM MATERIAL)
- PRODUCT NAME:
- GASKET
- TYPE:
- CAM COVER
Now: $48.15Was: $53.50 -
On Sale
COMETIC Cam Cover Gasket - XL C9313F5
COMETIC
Now: $43.38Was: $48.20A failing cam cover gasket compromises engine sealing and invites oil leakage into critical ignition components—exactly what you don't need during a race or long-distance drive. COMETIC's cam cover...20111502- SKU:
- 20111502
- Availability:
- Ships Same Business Day
- Weight:
- 0.25 LBS
- MATERIAL:
- AFM (ALUMINUM FOAM MATERIAL)
- PRODUCT NAME:
- GASKET
- THICKNESS IMPERIAL:
- 0.060'
- TYPE:
- CAM COVER
- RIDING STYLE:
- STREET
- THICKNESS:
- 1,52 MM (0,060')
- THICKNESS METRIC:
- 1.52 MM
- UNITS:
- 5 PACK
Now: $43.38Was: $48.20Qty in Cart: 0Quantity:Price:Now: $43.38Was: $48.20Subtotal: -
On Sale
COMETIC Pushrod O-Ring - M8 C9586-M8
COMETIC
MSRP: $15.70Now: $14.13Was: $15.70Pushrod seal degradation leads to oil leakage and compression loss—two problems that compromise engine reliability and performance. The COMETIC M8 Pushrod O-Ring delivers consistent sealing integrity...09351030- SKU:
- 09351030
- Availability:
- Ships Same Business Day
- Weight:
- 0.05 LBS
- APPLICATION:
- PUSHROD TUBE
- MATERIAL:
- VITON
- RIDING STYLE:
- STREET
- PRODUCT NAME:
- SEAL
- UNITS:
- KIT
MSRP: $15.70Now: $14.13Was: $15.70Qty in Cart: 0Quantity:Price:MSRP: $15.70Now: $14.13Was: $15.70Subtotal: -
On Sale
COMETIC Oil Pump Seal C10305
COMETIC
MSRP: $10.95Now: $9.86Was: $10.95An oil pump seal failure can lead to catastrophic oil leakage, dropping pressure and starving critical engine bearings of lubrication during high-performance runs. The COMETIC Oil Pump Seal C10305...09351181- SKU:
- 09351181
- Availability:
- Ships Same Business Day
- Weight:
- 0.02 LBS
- PRODUCT NAME:
- SEAL
- UNITS:
- EACH
- RIDING STYLE:
- STREET
- MATERIAL:
- VITON
- TYPE:
- OIL PUMP
MSRP: $10.95Now: $9.86Was: $10.95 -
On Sale
COMETIC Valve Stem Seal C10202
COMETIC
Now: $14.22Was: $15.80Valve stem seals are critical to engine longevity—they prevent oil from seeping into the combustion chamber, which causes excessive smoke, oil consumption, and carbon buildup. The COMETIC C10202 uses...09350991- SKU:
- 09350991
- Availability:
- Ships Same Business Day
- Weight:
- 0.10 LBS
- PRODUCT NAME:
- SEAL
- APPLICATION:
- VALVE COVER
- RIDING STYLE:
- STREET
- UNITS:
- KIT
Now: $14.22Was: $15.80 -
On Sale
COMETIC Intake Seal C10203
COMETIC
Now: $12.15Was: $13.50A proper intake seal is critical to maintaining consistent air flow and preventing vacuum leaks that compromise engine efficiency and performance tuning. The COMETIC Intake Seal C10203 delivers...09350992- SKU:
- 09350992
- Availability:
- Ships Same Business Day
- Weight:
- 0.11 LBS
- PRODUCT NAME:
- SEAL
- UNITS:
- 4 PACK
- APPLICATION:
- INTAKE MANIFOLD
- RIDING STYLE:
- STREET
Now: $12.15Was: $13.50 -
On Sale
COMETIC Throttle Body Seal C10204
COMETIC
Now: $36.99Was: $41.10A leaking throttle body seal compromises fuel atomization and engine response, leading to inconsistent air-fuel ratios and performance loss. The COMETIC C10204 delivers a precision seal that...09350993- SKU:
- 09350993
- Availability:
- Ships Same Business Day
- Weight:
- 0.16 LBS
- RIDING STYLE:
- STREET
- PRODUCT NAME:
- SEAL
- APPLICATION:
- THROTTLE BODY
- UNITS:
- KIT
Now: $36.99Was: $41.10 -
On Sale
COMETIC Neutral Indicator Washer C9497
COMETIC
Now: $6.03Was: $6.70The COMETIC Neutral Indicator Washer C9497 is an essential component for maintaining precise ignition timing and engine synchronization in high-performance applications. This OEM-quality washer...09350204- SKU:
- 09350204
- Availability:
- Ships Same Business Day
- Weight:
- 0.10 LBS
- APPLICATION:
- NEUTRAL GEAR SWITCH
- UNITS:
- 10 PACK
- MATERIAL:
- NYLON
- APPLICATION:
- TRANSMISSION
- THICKNESS:
- 0,063'
- THICKNESS IMPERIAL:
- 0.063'
- PRODUCT NAME:
- WASHER
- RIDING STYLE:
- STREET
Now: $6.03Was: $6.70 -
On Sale
COMETIC Camshaft Rubber Seal C9519
COMETIC
Now: $4.77Was: $5.30A failing camshaft seal can silently drain your engine's oil and compromise performance when you can't afford the downtime. The COMETIC C9519 is engineered to maintain a consistent, leak-free seal...09350206- SKU:
- 09350206
- Availability:
- Ships Same Business Day
- Weight:
- 0.16 LBS
- MATERIAL:
- RUBBER
- UNITS:
- 10 PACK
- PRODUCT NAME:
- SEAL
- APPLICATION:
- CAMSHAFT
- RIDING STYLE:
- STREET
- MATERIAL:
- VITON
Now: $4.77Was: $5.30 -
On Sale
COMETIC Main Shaft Seal - 5 Pack C9523
COMETIC
Now: $15.21Was: $16.90Main shaft seals are critical components that prevent fluid leakage and contamination in your transmission or differential housing. A compromised seal leads to fluid loss, bearing damage, and...09350208- SKU:
- 09350208
- Availability:
- Ships Same Business Day
- Weight:
- 0.34 LBS
- MATERIAL:
- VITON
- PRODUCT NAME:
- SEAL
- RIDING STYLE:
- STREET
- APPLICATION:
- MAIN CRANKSHAFT
- UNITS:
- 5 PACK
Now: $15.21Was: $16.90 -
On Sale
COMETIC Lower Rocker Cover Rubber Gasket C9280
COMETIC
Now: $18.09Was: $20.10A leaking rocker cover gasket compromises engine sealing and invites oil contamination into your combustion chamber—a fast path to performance loss and engine damage. The COMETIC Lower Rocker Cover...09350224- SKU:
- 09350224
- Availability:
- Ships Same Business Day
- Weight:
- 0.16 LBS
- PRODUCT NAME:
- GASKET
- MATERIAL:
- VITON
- UNITS:
- 5 PACK
- MOUNTING POSITION:
- LOWER
- MOUNTING POSITION:
- OUTER
- RIDING STYLE:
- STREET
- TYPE:
- ROCKER BOX
Now: $18.09Was: $20.10 -
On Sale
COMETIC Head Gasket - Big Twin C10120
COMETIC
MSRP: $61.90Now: $55.71Was: $61.90A head gasket is only as reliable as its ability to maintain a consistent seal under extreme combustion pressures and temperature cycling—and the COMETIC C10120 is engineered to deliver exactly that...09344739- SKU:
- 09344739
- Availability:
- Ships Same Business Day
- Weight:
- 0.20 LBS
- RIDING STYLE:
- STREET
- THICKNESS IMPERIAL:
- 0,040'
- THICKNESS METRIC:
- 1.02 MM
- BORE SIZE:
- 3,875'
- MATERIAL:
- LAYERED STEEL
- BORE SIZE IMPERIAL:
- 3.875'
- TYPE:
- CYLINDER HEAD
- PRODUCT NAME:
- GASKET
- THICKNESS:
- 1,02 MM (0,040')
- UNITS:
- PAIR
MSRP: $61.90Now: $55.71Was: $61.90 -
On Sale
COMETIC Complete Gasket Kit - Big Twin C10121
COMETIC
MSRP: $169.00Now: $152.10Was: $169.00A complete gasket kit is the foundation of engine reliability—especially in Big Twin applications where sustained performance demands perfect sealing. The COMETIC C10121 eliminates the guesswork of...09344740- SKU:
- 09344740
- Availability:
- Ships Same Business Day
- Weight:
- 1.15 LBS
- BORE SIZE:
- 4,125'
- BORE SIZE IMPERIAL:
- 4.125'
- UNITS:
- KIT
- MATERIAL:
- AFM (ALUMINUM FOAM MATERIAL)
- PRODUCT NAME:
- GASKET KIT
- RIDING STYLE:
- STREET
- MATERIAL:
- STEEL
- TYPE:
- MOTOR
- THICKNESS IMPERIAL:
- 0,040'
- THICKNESS METRIC:
- 1.02 MM
MSRP: $169.00Now: $152.10Was: $169.00Qty in Cart: 0Quantity:Price:MSRP: $169.00Now: $152.10Was: $169.00Subtotal: -
On Sale
COMETIC Complete Gasket Kit - Big Twin C10121-036
COMETIC
MSRP: $169.00Now: $152.10Was: $169.00A complete gasket failure can sideline your Big Twin engine indefinitely, costing you race time and credibility. The COMETIC Complete Gasket Kit delivers OEM-equivalent sealing across all critical...09344741- SKU:
- 09344741
- Availability:
- Ships Same Business Day
- Weight:
- 1.10 LBS
- BORE SIZE:
- 4,125'
- TYPE:
- MOTOR
- UNITS:
- KIT
- MATERIAL:
- STEEL
- THICKNESS IMPERIAL:
- 0,036'
- BORE SIZE IMPERIAL:
- 4.125'
- MATERIAL:
- AFM (ALUMINUM FOAM MATERIAL)
- PRODUCT NAME:
- GASKET KIT
- THICKNESS METRIC:
- 0.91 MM
- RIDING STYLE:
- STREET
MSRP: $169.00Now: $152.10Was: $169.00Qty in Cart: 0Quantity:Price:MSRP: $169.00Now: $152.10Was: $169.00Subtotal: -
On Sale
COMETIC Head Gasket C10037
COMETIC
MSRP: $61.90Now: $55.71Was: $61.90A head gasket failure can sideline your engine and drain your wallet—the COMETIC C10037 prevents catastrophic leaks by maintaining a consistent seal across harsh operating conditions and high...09344650- SKU:
- 09344650
- Availability:
- Ships Same Business Day
- Weight:
- 0.30 LBS
- PRODUCT NAME:
- GASKET
- RIDING STYLE:
- STREET
- BORE SIZE:
- 3,8125'
- THICKNESS:
- 1,02 MM (0,040')
- THICKNESS IMPERIAL:
- 0,040'
- TYPE:
- CYLINDER HEAD
- BORE SIZE IMPERIAL:
- 3.8125'
- THICKNESS METRIC:
- 1.02 MM
- UNITS:
- PAIR
- MATERIAL:
- LAYERED STEEL
MSRP: $61.90Now: $55.71Was: $61.90 -
On Sale
COMETIC Cylinder Base Gasket C10038
COMETIC
MSRP: $33.55Now: $30.20Was: $33.55A quality cylinder base gasket is critical to maintaining compression integrity and preventing oil seepage in your Sportster engine. The COMETIC C10038 is engineered to withstand the thermal cycles...09344651- SKU:
- 09344651
- Availability:
- Ships Same Business Day
- Weight:
- 0.05 LBS
- BORE SIZE IMPERIAL:
- 3.8125'
- THICKNESS IMPERIAL:
- 0,020'
- RIDING STYLE:
- STREET
- THICKNESS:
- 0,51 MM (0,020')
- MATERIAL:
- VITON
- THICKNESS METRIC:
- 0.51 MM
- PRODUCT NAME:
- GASKET
- TYPE:
- CYLINDER BASE
- UNITS:
- PAIR
MSRP: $33.55Now: $30.20Was: $33.55Qty in Cart: 0Quantity:Price:MSRP: $33.55Now: $30.20Was: $33.55Subtotal: -
On Sale
COMETIC Top End Gasket - XL1200 C9219
COMETIC
MSRP: $142.75Now: $128.48Was: $142.75Top-end gasket failure can sideline your bike at the worst possible moment—and replacing individual gaskets piecemeal wastes time and money. The COMETIC EST gasket kit eliminates guesswork by...09341664- SKU:
- 09341664
- Availability:
- Ships Same Business Day
- Weight:
- 0.95 LBS
- DISPLACEMENT:
- 1200 CC
- MATERIAL:
- RUBBER
- TYPE:
- TOP END
- UNITS:
- KIT
- MATERIAL:
- STAINLESS STEEL
- THICKNESS IMPERIAL:
- 0,040'
- THICKNESS METRIC:
- 1.02 MM
- BORE SIZE:
- 3,8125'
- BORE SIZE IMPERIAL:
- 3.8125'
- ENGINE TYPE:
- 4-STROKE
- PRODUCT NAME:
- GASKET KIT
- RIDING STYLE:
- STREET
MSRP: $142.75Now: $128.48Was: $142.75Qty in Cart: 0Quantity:Price:MSRP: $142.75Now: $128.48Was: $142.75Subtotal: -
On Sale
COMETIC Breather Gasket - Twin Cam C9579
COMETIC
Now: $7.38Was: $8.20A failing breather gasket compromises crankcase ventilation and invites oil leakage around your cover—both problems that degrade engine performance and create messy maintenance headaches. The COMETIC...09341332- SKU:
- 09341332
- Availability:
- Ships Same Business Day
- Weight:
- 0.07 LBS
- RIDING STYLE:
- STREET
- THICKNESS:
- 0,79 MM (0,031')
- THICKNESS METRIC:
- 0.79 MM
- MATERIAL:
- FIBER
- PRODUCT NAME:
- GASKET
- UNITS:
- 10 PACK
- THICKNESS IMPERIAL:
- 0,031'
- TYPE:
- BREATHER
Now: $7.38Was: $8.20 -
On Sale
COMETIC Breather Filter - Twin Cam C9679
COMETIC
Now: $10.80Was: $12.00A clean breather system is critical to maintaining engine longevity and preventing crankcase pressure buildup that can compromise seals and gaskets. The COMETIC Breather Filter C9679 is a direct...09341333- SKU:
- 09341333
- Availability:
- Ships Same Business Day
- Weight:
- 0.05 LBS
- MATERIAL:
- FOAM
- TYPE:
- BREATHER
- RIDING STYLE:
- STREET
- PRODUCT NAME:
- GASKET
- UNITS:
- 10 PACK
Now: $10.80Was: $12.00 -
On Sale
COMETIC Breather Baffle Gasket C9580
COMETIC
Now: $7.38Was: $8.20A worn or damaged breather baffle gasket compromises crankcase ventilation efficiency, allowing pressure buildup and potential oil leakage that can damage seals and contaminate your engine bay. The...09341334- SKU:
- 09341334
- Availability:
- Ships Same Business Day
- Weight:
- 0.08 LBS
- RIDING STYLE:
- STREET
- THICKNESS METRIC:
- 0.79 MM
- MATERIAL:
- FIBER
- PRODUCT NAME:
- GASKET
- THICKNESS:
- 0,79 MM (0,031')
- UNITS:
- 10 PACK
- THICKNESS IMPERIAL:
- 0,031'
- TYPE:
- BREATHER
Now: $7.38Was: $8.20
