124/128 M8 SLEEPER BIG BORE KITSNo replacement for displacement, right?
Our Sleeper kits easily turn your 107 M8 into a 124, or your 114/117 M8 into a 128 inch powerhouse! Kit includes new 4.25” bore cylinders fitted with Zippers-designed forged pistons, Red Shift 468 or 472 cam, Red Shift Dual-Piston tensioner with offset drive gears, quikee pushrods and chrome or black covers, new cam bearing and gaskets. Incredible power gains with stock heads, even more if you add our Stage II blueprint headwork!
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Not legal for sale or use in California on any pollution controlled motor vehicle.
Not legal for sale or use on any EPA pollution controlled motor vehicle.
Zipper's is here to help, if you have a question(s) please scroll down and fill out the form and hit send. We will review your question(s) and we will be in contact.
The Sport-Touring Kit is a great choice between our popular Sleeper and Muscle kits!Developed for the experienced rider that wants touring reliability and the widest power curve in its class! The Sport-Touring kit matches our Stage II M8 headwork blueprinting with our Red Shift 548 camshaft and 4.25” cylinder kit that results in big power across the entire RPM range. Twist the throttle at nearly any RPM and you’re rewarded with immediate, seemingly effortless forward motion! The key to this great power is the carefully engineered combination of airflow, camshaft timing, compression, displacement and Zipper’s legendary commitment to testing and machining detail. All of these components are produced in-house at Zipper’s so you can be assured of the highest quality and reliable results!
Not legal for sale or use in California on any pollution controlled motor vehicle.
Not legal for sale or use on any EPA pollution controlled motor vehicle.
Zipper's Muscle 124 & 128" Kits for the M8 produce great power across a wide RPM range!
Our 4.250" bore drop-on cylinders are fitted with Zipper's-designed forged pistons and topped off with Zipper's Stage III head work featuring CNC porting, +1mm stainless valves and hi-lift springs. Our Red Shift 552 cam delivers HUGE torque as soon as you open the throttle, and carries it across the RPM range to provide instant acceleration from any RPM. Compression is set to a relatively modest 11:1. It has an amazing sound at idle and under load, with torque and horsepower at the 150’s level. Peak torque starts at 2,800 rpm – 50 pounds more than stock, staying at nearly 150 ft/lbs for over 2,000 RPM, right where you ride! Tire life not guaranteed!
Not legal for sale or use in California on any pollution controlled motor vehicle.
Not legal for sale or use on any EPA pollution controlled motor vehicle.
Zipper's is here to help, if you have a question(s) please scroll down and fill out the form and hit send. We will review your question(s) and we will be in contact.
Zipper's engineering team developed the Muscle 124 and 128 Stage 4 kits for riders who want to win, every time. Careful testing of the latest technologies and components yields incredible power from the M8 platform on pump gas. Cylinder heads receive Zipper's CNC porting to Stage IV specs for maximum flow using +2mm oversize stainless valves, and Zipper’s 4.250” bore cylinders are fitted with 12:1 thermal and friction coated pistons. Our Red Shift 588 cam optimizes the output of these powerful components; careful selection of intake, exhaust and tuning delivers impressive results to 6500 RPM. This is not a bolt-on kit. It requires strengthening of the engine base and drive line upgrades - not unexpected when you are almost doubling the factory output - and should be executed by an experienced professional. “Walk softly, but carry a Big Gun!”
Not legal for sale or use in California on any pollution controlled motor vehicle.
Not legal for sale or use on any EPA pollution controlled motor vehicle.