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
-
KB PERFORMANCE Piston Kit - Twin Cam 88 KB425C.010
KB PERFORMANCE
$287.95If you're building or rebuilding a Twin Cam 88 engine for serious performance, piston quality directly impacts reliability, ring seal, and longevity under boost or sustained high RPM. KB Performance's hypereutectic aluminum construction and precision...09106089- SKU:
- 09106089
- Availability:
- Ships Same Business Day
- Weight:
- 3.01 LBS
- UNITS:
- KIT
- BORE SIZE IMPERIAL:
- 3.750'
- COMPRESSION RATIO IMPERIAL:
- 8.8:1
- PISTON HEAD SHAPE:
- FLAT TOP
- PISTON MATERIAL:
- HYPEREUTECTIC ALLOY
- RIDING STYLE:
- STREET
- BORE OVERSIZE - IMPERIAL:
- +0.010'
- PRODUCT NAME:
- PISTON KIT
$287.95 -
KB PERFORMANCE Piston Kit - Twin Cam 88 KB425C.020
KB PERFORMANCE
$287.95If you're serious about Twin Cam 88 performance and longevity, piston quality directly impacts your engine's reliability and power output. KB Performance pistons are manufactured to exacting tolerances and leverage hypereutectic aluminum technology to...09106090- SKU:
- 09106090
- Availability:
- Ships Same Business Day
- Weight:
- 3.06 LBS
- COMPRESSION RATIO IMPERIAL:
- 8.8:1
- UNITS:
- KIT
- BORE SIZE IMPERIAL:
- 3.750'
- PISTON HEAD SHAPE:
- FLAT TOP
- PISTON MATERIAL:
- HYPEREUTECTIC ALLOY
- BORE OVERSIZE - IMPERIAL:
- +0.020'
- PRODUCT NAME:
- PISTON KIT
- RIDING STYLE:
- STREET
$287.95 -
KB PERFORMANCE Piston Kit - Twin Cam 88 KB425C.030
KB PERFORMANCE
$287.95If you're building a high-performance Twin Cam 88 engine, piston quality directly impacts reliability and ring seal integrity. KB Performance pistons are diamond-machined to exacting tolerances—plus or minus one gram and half a thousandth-inch across the...09106091- SKU:
- 09106091
- Availability:
- Ships Same Business Day
- Weight:
- 3.06 LBS
- COMPRESSION RATIO IMPERIAL:
- 8.8:1
- UNITS:
- KIT
- BORE SIZE IMPERIAL:
- 3.750'
- PISTON HEAD SHAPE:
- FLAT TOP
- PISTON MATERIAL:
- HYPEREUTECTIC ALLOY
- BORE OVERSIZE - IMPERIAL:
- +0.030'
- PRODUCT NAME:
- PISTON KIT
- RIDING STYLE:
- STREET
$287.95 -
KB PERFORMANCE Piston Kit - Twin Cam 88 KB426C.STD
KB PERFORMANCE
$295.95If you're building or rebuilding a Twin Cam 88 engine and demand maximum ring seal with minimal piston rock, KB Performance pistons deliver the precision tolerances and material science that separate high-revving reliability from failure. The T-5...09106092- SKU:
- 09106092
- Availability:
- Ships Same Business Day
- Weight:
- 3.21 LBS
- BORE OVERSIZE - IMPERIAL:
- STANDARD
- UNITS:
- KIT
- BORE SIZE IMPERIAL:
- 3.750'
- COMPRESSION RATIO IMPERIAL:
- 10.5:1
- PISTON MATERIAL:
- HYPEREUTECTIC ALLOY
- RIDING STYLE:
- STREET
- PRODUCT NAME:
- PISTON KIT
$295.95 -
KB PERFORMANCE Piston Kit - Twin Cam 88 KB426C.010
KB PERFORMANCE
$295.95If you're building a high-revving Twin Cam 88 engine that demands precision ring seal and minimal piston rock, KB Performance pistons are engineered to deliver exactly that. The diamond-machined construction and tight tolerances eliminate the slack found...09106094- SKU:
- 09106094
- Availability:
- Ships Same Business Day
- Weight:
- 3.26 LBS
- PISTON MATERIAL:
- HYPEREUTECTIC ALLOY
- UNITS:
- KIT
- PRODUCT NAME:
- PISTON KIT
- RIDING STYLE:
- STREET
- BORE OVERSIZE - IMPERIAL:
- +0.010'
- BORE SIZE IMPERIAL:
- 3.750'
- COMPRESSION RATIO IMPERIAL:
- 10.5:1
$295.95Qty in Cart: 0Quantity:Price:$295.95Subtotal: -
KB PERFORMANCE Piston Kit - Twin Cam 88 KB426C.020
KB PERFORMANCE
$295.95If you're building or rebuilding a Twin Cam 88 engine and demand maximum ring seal, minimal piston rock, and extended component life, KB Performance pistons are engineered to deliver. Their tight tolerances and hypereutectic aluminum construction allow...09106095- SKU:
- 09106095
- Availability:
- Ships Same Business Day
- Weight:
- 3.26 LBS
- PISTON MATERIAL:
- HYPEREUTECTIC ALLOY
- PRODUCT NAME:
- PISTON KIT
- RIDING STYLE:
- STREET
- BORE OVERSIZE - IMPERIAL:
- +0.020'
- UNITS:
- KIT
- BORE SIZE IMPERIAL:
- 3.750'
- COMPRESSION RATIO IMPERIAL:
- 10.5:1
$295.95Qty in Cart: 0Quantity:Price:$295.95Subtotal: -
KB PERFORMANCE Piston Kit - Standard - M8 KB542LCA.STD
KB PERFORMANCE
$427.95If you're pushing your M8 to the edge, factory pistons won't cut it. The KB PERFORMANCE Super Duty Series delivers the durability and precision clearances you need for sustained high-RPM operation, with engineered coatings that tighten up under load...09105724- SKU:
- 09105724
- Availability:
- Ships Same Business Day
- Weight:
- 2.96 LBS
- COMPRESSION RATIO IMPERIAL:
- 11.0:1
- STROKE LENGTH IMPERIAL:
- 4-1/2'
- UNITS:
- KIT
- DISPLACEMENT:
- 117'
- PRODUCT NAME:
- PISTON KIT
- RIDING STYLE:
- STREET
- BORE SIZE METRIC:
- 104.77 MM
- PISTON MATERIAL:
- ALUMINUM
$427.95Qty in Cart: 0Quantity:Price:$427.95Subtotal: -
KB PERFORMANCE PISTON KIT M8 117" +020 KB542LCA.020
KB PERFORMANCE
$427.95If you're pushing your M8 to the 117" displacement sweet spot, you need pistons engineered for high-RPM reliability and consistent ring sealing under boost. The KB Performance Super Duty Series delivers the precision tolerances and abradable coatings...09105726- SKU:
- 09105726
- Availability:
- Ships Same Business Day
- Weight:
- 2.91 LBS
- PRODUCT NAME:
- PISTON KIT
- RIDING STYLE:
- STREET
- STROKE LENGTH IMPERIAL:
- 4-1/2'
- BORE SIZE METRIC:
- 104.77 MM
- COMPRESSION RATIO IMPERIAL:
- 11.0:1
- DISPLACEMENT:
- 117'
- PISTON MATERIAL:
- ALUMINUM
- UNITS:
- KIT
$427.95 -
KB PERFORMANCE Piston Kit - 124" - Standard - M8 KB576LCA.STD
KB PERFORMANCE
$446.95If you're building or rebuilding a 124-cubic-inch M8 engine, piston selection is non-negotiable—the wrong choice will cost you reliability, power, and consistency. KB Performance pistons are engineered for maximum durability in high-stress applications,...09106177- SKU:
- 09106177
- Availability:
- Ships Same Business Day
- Weight:
- 3.15 LBS
- BORE SIZE IMPERIAL:
- 4.250'
- PRODUCT NAME:
- PISTON KIT
- RIDING STYLE:
- STREET
- DISPLACEMENT:
- 124'
- BORE - OVERSIZE:
- STANDARD
- BORE OVERSIZE - IMPERIAL:
- STANDARD
- UNITS:
- KIT
$446.95Qty in Cart: 0Quantity:Price:$446.95Subtotal: -
KB PERFORMANCE Piston Kit - 124" - +.005" - M8 KB576LCA.005
KB PERFORMANCE
$446.95If you're building or rebuilding a big-inch M8 engine, piston quality directly impacts reliability, ring seal, and power output. KB Performance pistons are engineered to exacting tolerances with proven materials that handle sustained high RPM and boost...09106178- SKU:
- 09106178
- Availability:
- Ships Same Business Day
- Weight:
- 3.15 LBS
- BORE OVERSIZE - IMPERIAL:
- +0.005'
- PRODUCT NAME:
- PISTON KIT
- RIDING STYLE:
- STREET
- DISPLACEMENT:
- 124'
- BORE - OVERSIZE:
- +0,005'
- UNITS:
- KIT
$446.95 -
KB PERFORMANCE Piston Kit KB258.030
KB PERFORMANCE
$233.95If you're building or rebuilding an engine that demands precision and longevity, KB Performance pistons deliver the tight tolerances and superior ring seal that separate a reliable build from a mediocre one. The 390 hypereutectic aluminum alloy...09102017- SKU:
- 09102017
- Availability:
- Ships Same Business Day
- Weight:
- 2.75 LBS
- PISTON MATERIAL:
- HYPEREUTECTIC ALLOY
- BORE OVERSIZE - IMPERIAL:
- +0.030'
- COMPRESSION RATIO IMPERIAL:
- 8.6:1
- PRODUCT NAME:
- PISTON KIT
- RIDING STYLE:
- STREET
- UNITS:
- KIT
- BORE SIZE IMPERIAL:
- 3.498'
$233.95Qty in Cart: 0Quantity:Price:$233.95Subtotal: -
KB PERFORMANCE Piston Kit KB305.040
KB PERFORMANCE
$246.95If you're serious about maximizing engine performance and longevity, piston quality is non-negotiable. The KB PERFORMANCE Piston Kit KB305.040 delivers the tight tolerances and precision engineering that separate race-grade components from off-the-shelf...09102019- SKU:
- 09102019
- Availability:
- Ships Same Business Day
- Weight:
- 2.70 LBS
- PRODUCT NAME:
- PISTON KIT
- RIDING STYLE:
- STREET
- UNITS:
- KIT
- BORE SIZE IMPERIAL:
- 3.498'
- COMPRESSION RATIO IMPERIAL:
- 9.6:1
- BORE OVERSIZE - IMPERIAL:
- +0.040'
- PISTON MATERIAL:
- HYPEREUTECTIC ALLOY
$246.95 -
KB PERFORMANCE Piston Kit - Twin Cam KB409C.STD
KB PERFORMANCE
$236.95If you're building or rebuilding a Twin Cam engine, piston quality directly impacts reliability, power delivery, and ring seal—and that's where KB Performance separates itself from the field. The KB409C.STD uses precision diamond-machining and T-5...09100915- SKU:
- 09100915
- Availability:
- Ships Same Business Day
- Weight:
- 2.60 LBS
- BORE SIZE IMPERIAL:
- 3.875'
- COMPRESSION RATIO IMPERIAL:
- 10.0:1
- PISTON MATERIAL:
- HYPEREUTECTIC ALLOY
- RIDING STYLE:
- STREET
- BORE OVERSIZE - IMPERIAL:
- STANDARD
- PRODUCT NAME:
- PISTON KIT
- UNITS:
- KIT
$236.95 -
KB PERFORMANCE Piston Kit - Twin Cam KB409C.010
KB PERFORMANCE
$236.95If you're building a high-performance engine that demands precision and durability, KB Performance pistons deliver the tight tolerances and superior ring seal that separate competitive engines from the rest. The T-5 heat-treated 390 hypereutectic...09100917- SKU:
- 09100917
- Availability:
- Ships Same Business Day
- Weight:
- 2.66 LBS
- BORE SIZE IMPERIAL:
- 3.875'
- COMPRESSION RATIO IMPERIAL:
- 10.0:1
- PRODUCT NAME:
- PISTON KIT
- RIDING STYLE:
- STREET
- BORE OVERSIZE - IMPERIAL:
- +0.010'
- UNITS:
- KIT
- PISTON MATERIAL:
- HYPEREUTECTIC ALLOY
$236.95 -
KB PERFORMANCE Forged Piston Kit KB922C.STD
KB PERFORMANCE
$285.57KB Performance forged pistons deliver the strength and precision your engine demands when boost levels climb or RPM targets exceed stock capabilities. The 4032 aluminum alloy construction resists thermal stress and detonation damage far better than cast...09100930- SKU:
- 09100930
- Availability:
- Ships Same Business Day
- Weight:
- 2.45 LBS
- COMPRESSION RATIO IMPERIAL:
- 9.0:1
- RIDING STYLE:
- STREET
- BORE OVERSIZE - IMPERIAL:
- STANDARD
- BORE SIZE IMPERIAL:
- 3.498'
- PISTON MATERIAL:
- 4032 ALUMINUM ALLOY
- BORE - OVERSIZE:
- STANDARD
- UNITS:
- KIT
$285.57Qty in Cart: 0Quantity:Price:$285.57Subtotal: -
KB PERFORMANCE Forged Piston Kit - Twin Cam KB906C.STD
KB PERFORMANCE
$322.95If you're rebuilding a Twin Cam engine or pushing beyond stock power levels, piston quality directly impacts reliability, longevity, and combustion efficiency. The KB PERFORMANCE Forged Piston Kit delivers OEM-grade construction with forged 4032 aluminum...09100935- SKU:
- 09100935
- Availability:
- Ships Same Business Day
- Weight:
- 2.41 LBS
- COMPRESSION RATIO IMPERIAL:
- 10.5:1
- PISTON MATERIAL:
- 4032 ALUMINUM ALLOY
- UNITS:
- KIT
- BORE - OVERSIZE:
- STANDARD
- BORE OVERSIZE - IMPERIAL:
- STANDARD
- BORE SIZE IMPERIAL:
- 3.875'
- RIDING STYLE:
- STREET
$322.95Qty in Cart: 0Quantity:Price:$322.95Subtotal: -
KB PERFORMANCE Forged Piston Kit - Twin Cam KB909C.STD
KB PERFORMANCE
$322.95If you're rebuilding a Twin Cam engine or pushing higher compression ratios, quality pistons are non-negotiable—they're the foundation of reliability under load. KB Performance's forged 4032 aluminum construction delivers the strength needed for...09100939- SKU:
- 09100939
- Availability:
- Ships Same Business Day
- Weight:
- 2.50 LBS
- BORE - OVERSIZE:
- STANDARD
- BORE OVERSIZE - IMPERIAL:
- STANDARD
- COMPRESSION RATIO IMPERIAL:
- 10.5:1
- BORE SIZE IMPERIAL:
- 3.875'
- RIDING STYLE:
- STREET
- PISTON MATERIAL:
- 4032 ALUMINUM ALLOY
- UNITS:
- KIT
$322.95 -
KB PERFORMANCE Super-Duty Piston KB909LCA.STD
KB PERFORMANCE
$410.95Piston rock and ring flutter are silent killers of engine efficiency and longevity—they compromise seal integrity, waste power, and introduce unwanted noise. The KB PERFORMANCE Super-Duty Piston KB909LCA.STD eliminates these issues entirely through its...09105044- SKU:
- 09105044
- Availability:
- Ships Same Business Day
- Weight:
- 2.60 LBS
- PISTON MATERIAL:
- ALUMINUM
- UNITS:
- KIT
- DISPLACEMENT:
- 103'
- RIDING STYLE:
- STREET
- BORE SIZE METRIC:
- 98.40 MM
- PRODUCT NAME:
- PISTON KIT
- STROKE LENGTH IMPERIAL:
- 4-3/8'
$410.95Qty in Cart: 0Quantity:Price:$410.95Subtotal: -
KB PERFORMANCE Super-Duty Piston KB661LCA.STD
KB PERFORMANCE
$442.95Piston rock and ring blow-by are silent killers of engine performance and longevity. The KB PERFORMANCE Super-Duty Piston KB661LCA.STD eliminates both through advanced skirt coating technology that self-hones to perfect clearance on startup, giving you...09105047- SKU:
- 09105047
- Availability:
- Ships Same Business Day
- Weight:
- 2.80 LBS
- COMPRESSION RATIO IMPERIAL:
- 10.0:1
- PRODUCT NAME:
- PISTON KIT
- RIDING STYLE:
- STREET
- STROKE LENGTH IMPERIAL:
- 4-3/8'
- BORE SIZE METRIC:
- 101.60 MM
- DISPLACEMENT:
- 110'
- PISTON MATERIAL:
- ALUMINUM
- UNITS:
- KIT
$442.95 -
KB PERFORMANCE Super-Duty Piston KB662LCA.STD
KB PERFORMANCE
$410.95The KB PERFORMANCE Super-Duty Piston KB662LCA.STD eliminates common failure points that compromise ring seal and engine longevity. Its proprietary skirt coating technology self-hones to perfect clearance on startup, eliminating piston rock and the noise...09105049- SKU:
- 09105049
- Availability:
- Ships Same Business Day
- Weight:
- 2.90 LBS
- DISPLACEMENT:
- 117'
- PRODUCT NAME:
- PISTON KIT
- STROKE LENGTH IMPERIAL:
- 4-3/8'
- COMPRESSION RATIO IMPERIAL:
- 10.0:1
- UNITS:
- KIT
- BORE SIZE METRIC:
- 104.80 MM
- PISTON MATERIAL:
- ALUMINUM
- RIDING STYLE:
- STREET
$410.95
