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Why put your bike engine back together with stock parts—when you can upgrade with one of the S&S Cycle flywheel assemblies? These 3-piece units are forged and heat-treated from 4140 steel, making them harder and stronger than stock. They're precision-machined to be truer (for less vibration), and are assembled with integral mainshafts and lightweight connecting rod forgings. Stock flywheels shift out of true under heavy loads; improve your motorcycle with an S&S Cycle flywheel assembly.
Not Yet Reviewed
$1,488.95
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$1,599.95
S&S Cycle offers 128 in. power packages with chain drive cam for a variety of Harley-Davidson© street bikes from 2017 and up. Kit details include: BIG BORE KIT: * 4.250 in. bore * Forged pistons * 11.1:1 compression ratio OIL PUMP/CAM PLATE: * Precision-machined from billet aluminum * Passage plugs removable for servicing * Independent scavenge sections for flywheel cavity and cam chest * Debris screens in both scavenge pickups * Magnet in cam chest to help stop debris from entering oil pump * Increased flow capacity on both feed and scavenge side * Pressure relief valve is adjustable with unit installed in engine * Kits now include updated oil pump with groove for optional OEM oil seal PUSHRODS: * Quickee pushrods with chrome covers TAPPETS: * Hand-assembled to exacting tolerances * Reduced valvetrain noise from start-up to shut-down * Close tolerances for low leak-down rates * Fast pump-up and superior high-RPM performance TAPPET CUFFS: * Hard anodized black coating * Billet aluminum construction * Stronger than stock material eliminates distortion * Improve tappet stability in high lift and high RPM situations CAM: * S&S 550 cam—designed for big bore applications * Available in both chain drive and gear drive variations VALVE SPRINGS: * Work well with cams up to .605 lift * High performance conical single-wire spring * Includes top collars, keepers, and valve seals/bottom collars CAM CHAIN TENSIONER: * Precision-machined from billet aluminum * Thicker shoe for longer wear * Direct chain oiling * Larger piston for more consistent pressure * Tighter tolerances improve stability
Not Yet Reviewed
$3,265.95
S&S Cycle offers 128 in. power packages with gear drive cam for a variety of Harley-Davidson© street bikes from 2017 and up. Kit details include: BIG BORE KIT: * 4.250 in. bore * Forged pistons * 11.1:1 compression ratio OIL PUMP/CAM PLATE: * Precision-machined from billet aluminum * Passage plugs removable for servicing * Independent scavenge sections for flywheel cavity and cam chest * Debris screens in both scavenge pickups * Magnet in cam chest to help stop debris from entering oil pump * Increased flow capacity on both feed and scavenge side * Pressure relief valve is adjustable with unit installed in engine * Kits now include updated oil pump with groove for optional OEM oil seal PUSHRODS: * Quickee pushrods with chrome covers TAPPETS: * Hand-assembled to exacting tolerances * Reduced valvetrain noise from start-up to shut-down * Close tolerances for low leak-down rates * Fast pump-up and superior high-RPM performance TAPPET CUFFS: * Hard anodized black coating * Billet aluminum construction * Stronger than stock material eliminates distortion * Improve tappet stability in high lift and high RPM situations CAM: * S&S 550 cam—designed for big bore applications * Gear drive kits provide improved cam timing accuracy and eliminate stock chain tensioner * Gear drive kits include outer drive gears VALVE SPRINGS: * Work well with cams up to .605 lift * High performance conical single-wire spring * Includes top collars, keepers, and valve seals/bottom collars
Not Yet Reviewed
$3,427.95
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$3,460.95
The primary purpose of S&S Cycle's 750cc big bore kits is to enhance the performance of smaller engine models, particularly for the Street 500 or Street 750, giving them more power and acceleration. These stock bore cylinder kits are designed to increase the engine displacement by enlarging the cylinder bore, resulting in more power and torque compared to the stock engine, typically by converting a smaller displacement engine like a 500cc or 650cc into a 750cc unit. Many big bore kits are designed to be "bolt-on" upgrades, meaning they can be installed without requiring extensive engine modifications or machining, making them relatively easy to add to a motorcycle. Before ordering, make sure this kit is compatible with your specific street bike model.
Not Yet Reviewed
$869.95
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