Product Description

Knobtown Cycle proudly offers the S&S CYCLE PowerPak WaterCool 4.25″Bore4.375″Stroke M8 Blk w/Highlite. Your Kansas City motorcycle parts experts for over 40 years.

Key Features

• Bolt-on kit
• With updated fins
• No case machining required
• Forged pistons
• Made in the USA
• Includes oil pump/cam plate, pushrods, tappets, tappet cuffs, 550 camshaft, valve springs
• Oil Pump/Cam Plate:
• Precision machined from billet aluminum
• Passage plugs removable for servicing
• Independent scavenge sections for flywheel cavity and camchest
• Debris screens in both scavenge pickups
• Magnet in camchest to help to stop debris from entering oil pump
• 44% flow increase on supply side and 58% flow increase on scavenge side
• Pressure relief valve is adjustable with unit installed in engine
• Pushrods:
• Quickee pushrods
• Tappets:
• Hand assembled to exacting tolerances
• Reduced valve train noise from start up to shut down
• Close tolerances for low leak down rates
• Tappet Cuffs:
• Hard anodized black coating
• Billet aluminum construction
• Tappet stability in high lift and high rpm sitiuations

Product Specifications

• Part Number: 09040146
• Brand: S&S CYCLE
• Weight: 45.50 lbs

Expert Installation Services

Order now and choose ship-to-store for complimentary installation. Kansas City motorcycle service experts!

Notes: REPLACED 09040087

Part Locations

Stock levels last updated: January 27, 2026 11:58 AM

Professional Installation Available

Knobtown Cycle offers professional installation services. Contact us via a service request to learn more.