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1975 Norton Commando Interstate Restoration - $19,999 (Paynesville)
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THIS BIKE SHIFTS ON THE LEFT SIDE AND THE REAR BRAKE LEVER IS ON THE RIGHT SIDE.
Complete Frame-off Restoration by Zap Cycle, using every modern upgrade.
Looks very original, very vintage, but is loaded with modern upgrades and high performance parts.
FRAME-OFF RESTORATION / CUSTOM BUILD -- MANY HIGH PERFORMANCE UPGRADES
Note: When I say “genuine Norton parts”, I am referring to brand new parts made today by Andover Norton International Ltd. -- -- According to their website: “Andover Norton was established by Norton Villiers to continue the manufacture and distribution of Genuine Norton Spare Parts when Norton Motors Ltd was liquidated in 1977. Andover Norton has the original tooling and the original drawings and is continuously getting parts made to original or, where advisable, improved specification by our specialist suppliers- foundries, forges and machine shops most of which are based in the Midlands.”
Frame VIN Tag says 330996 -- Engine number 330996 -- Gearbox number 330996 -- Clean title in my name.
ENGINE
Twenty hours of head-work, porting and polishing.
New Carillo racing rods for an indestructible bottom-end.
Lightened and balanced flywheels for better acceleration and less vibration.
New connecting rod big-end bearings.
New Superblend main crankshaft bearings.
Kibblewhite valve guides.
Black Diamond valves.
Powermax pistons & rings.
Kibblewhite chrome moly pushrods, polished for faster oil return.
Lightened and polished rockers to give quicker acceleration.
High performance valve springs.
Cylinder deck has been milled for assured gasket sealing surfaces.
Genuine Norton Factory Racing 4S Torque Cam. This is a high lift, long duration cam designed to optimize mid-range torque. It’s easy to resist revving to red-line, as maximum power is produced throughout the mid-range.
Reground lifters.
Engine has moderately high compression. We're using 9-to-1 compression pistons, but we milled the cylinder deck surface for assured gasket sealing surfaces, and we milled the head .015”, all of which raises compression slightly over stock.
New genuine Norton camchain tensioner.
New genuine Norton camshaft bushings.
Positive crankcase ventilation valve.
Genuine Norton adjustable Vernier isolastics.
Dave Taylor head steady, which is the ultimate way of locking the engine/transmission unit in alignment with the rear wheel. The engine can move fore and aft, but not side-to-side, so handling is much improved and more predictable.
New pressure relief valve, upgraded to 60psi.
New genuine Norton oil pump.
Braided stainless steel rocker oil lines, for better reliability over OEM nylon lines.
Aftermarket oil cooler.
Anti-sumping valve.
Braided stainless steel oil lines throughout, including crankcase breather line.
Upgraded tachometer drive housing, preventing leaks at the cable hook-up.
New genuine Norton sump filter body.
New headers, with early Commando-style mufflers.
New muffler mounting rubbers, and new stainless steel muffler brackets.
All drain plugs and inspection plugs are new.
CLUTCH AND GEARBOX
Transmission has been completely and thoroughly overhauled.
Every part showing even minor wear has been replaced.
All bearings, bushings, and springs have been replaced with genuine Norton parts.
The kickstart lever assembly is new (genuine Norton).
Upgraded electric starter system, using a high output 4-brush starter motor and upgraded 18-cam sprag gear in lieu of out-dated 14-cam sprag gear (genuine Norton).
New genuine Norton crankshaft sprocket / outer sprag race (engine sprocket 06-4681) carries the new genuine Renold primary chain, as OEM.
New genuine Norton primary chain adjuster body assembly (06-4718) and new genuine Norton plunger assemblies (06-5341). It's imperative to replace these parts, as the tensioner body eventually becomes twisted out-of-square. When this happens, the plungers are forced outward, and cannot retract into the body, which results in exerting so much pressure against the primary chain as to stall the engine.
New genuine Norton starter shaft main gear/internal sprag race (06-4731) and genuine Norton needle bearing (06-4711).
New genuine Norton idler gears and new genuine Norton starter shaft gear (06-4707).
New solenoid, and heavy duty starter wires.
All clutch parts are new, including a genuine Norton clutch center (06-3979), a new upgraded diaphragm spring (06-0770), a new spring circlip (06-0751), Barnett fiber and steel clutch plates, genuine Norton clutch basket bearing (06-0750), and new adjuster screw and nut.
The clutch has been upgraded with our well-known ZM EZ-Pull clutch modification, which includes a needle roller clutch pushrod system and modified clutch actuating parts. All of which results in much less clutch drag, and a much lighter lever pull. Imagine a Norton with a very strong clutch, but a two-finger clutch-pull.
New genuine Norton clutch lever.
New Venhill easy-pull clutch cable.
CHARGING SYSTEM AND ELECTRICAL SYSTEM
We decided to upgrade all lighting to LED, which is polarity sensitive. To make it easy on the new owner, we wired the entire bike as a negative ground. The extra bright LED headlight is very impressive, yet has a vintage look to it.
Exclusive LED taillight, designed and custom-made by our shop, with integrated LED signal lights built into a stock BSA taillight. Signals are self-canceling.
LED instrument lights...
Pazon electronic ignition, which fires on only 10.8 volts. (Boyer requires 12.5 volts)
High output alternator.
New genuine Norton rotor, thus ensuring strong magnetism.
Tympanium solid-state regulator/rectifier.
Maintenance-free, glass-mat sealed battery, high cold-cranking-amps.
New ignition switch, two keys.
CARBURETORS
New upgraded Amal Premier carburetors, which are designed with forged, hard-anodized slides for longevity and non-stick.
Another improvement of the Premier carbs is a 'stay-up' float made from a military grade material that will not allow the float to sink for any reason.
This float is adjustable unlike the OEM float.
A Viton float needle is another bonus.
The carb uses a removeable pilot jet for better fine-tuning.
The OEM air box was leaky and troublesome, and the small air cleaner element was inefficient, so all of it was replaced with a dual K & N high-flow washable reusable air cleaner.
New genuine Norton throttle assembly.
New genuine Norton throttle cables.
Note: We eliminated the choke, because with the updated Premier carburetor, the choke lever is no longer necessary. The ticklers do a great job and are more than sufficient. The ticklers have been updated with the 'extended plunger modification' to keep gas from squirting all over your fingers.
INSTRUMENTS
Genuine Norton speedometer, overhauled by Nisonger Instrument, odometer at zero, actually 1.6 miles, as they test it before shipping.
Genuine Norton tachometer, overhauled by Nisonger Instrument.
We wanted a more 'vintage Commando' look, so the OEM Mk3 dash was eliminated.
The OEM Mk3 instrument carriers were black. For a cleaner look, we removed the black, and polished the aluminum to a chrome-like finish.
All warning lights are neatly installed in a new headlight shell. The outer two alert you when your signals are on, the front center is the HI-LO indicator, and the rear center is a low-charge warning. (The low-charge warning comes on very dimly when the charging drops below 13.0 V, as when you're idling. A bright glow is when charging drops below 12.0 V.)
The turn signals are self-canceling.
FRAME AND CHASSIS
Powder-coated frame and all black parts.
Every nut and bolt is brand new, stainless steel where practical and available.
New handle bars, “Semi-Western type” as were installed on USA bikes.
The OEM handle bar switch internals were overhauled.
The OEM Mk3 controls were black. For a cleaner look, we removed the black and polished the aluminum to a chrome-like finish.
New stainless steel front fender.
New stainless steel rear fender.
New steel gas tank, new petcocks, reserve installed on left side as is most practical.
High performance Motion Pro gas line with in-line fuel filters on both sides.
New steel side covers, freshly painted. Electric Start decal was omitted, as is more desirable.
Correct Mk3 mirrors.
New genuine Norton swingarm bushings.
New RGM Norton side stand with new genuine Norton bushings and return spring.
Good center-stand with new genuine Norton bushings and return spring.
New genuine Norton footpeg brackets.
New Interstate seat which has thicker foam padding than Roadster seat.
New RGM Norton chrome seat knobs.
Grab rail was eliminated, as is most desirable.
WHEELS and TIRES
We've lowered the center-of-gravity by rebuilding the wheels with lightweight 18” shouldered rims, stainless steel spokes and stainless steel nipples, all sourced from Buchanan Spoke & Rim of Azusa, CA.
Just as modern sport bikes run 17" wheels for better handling, the 18" versions make the Norton handle much better than with its OEM 19" wheels. Using 18" wheels lowers the center of gravity and allows the bike to handle better, steer better, and corner better.
We've installed radial tires, the front is a German-made Continental Conti Classic Attack 90/90R18 radial, the rear is a German-made Continental Conti Classic Attack 110/90R18 radial.
New wheel bearings.
FINAL DRIVE
We've chosen the 21 tooth countershaft sprocket for comfortable revs at highway speeds.
New high performance RK drive chain.
New genuine Norton steel chain guard.
New genuine Norton chain adjusters.
New genuine Norton rear sprocket (06-6011).
New rear wheel hub drive cushion rubbers.
FRONT-END and FRONT SUSPENSION and REAR SUSPENSION
Upgraded Timken steering bearings.
New genuine Norton isolastic bushings.
New genuine Norton swingarm bushings.
Progressive brand shocks, 13" eye-to-eye, which has proven to attain the best handling when using 18" wheels.
Overhauled front forks, new stanchion tubes, new internal bushings, improved fork springs made by Progressive.
BRAKES
New genuine Norton front rotor, part number 06-1885.
New genuine Norton front caliper, part number 06-1926.
New genuine Norton front master cylinder is the upgraded version, which has a 13mm bore, part number 06-5742/13. The 13mm bore increases the hydraulic fluid pressure at the caliper, resulting in much more powerful braking.
Ferodo Performance front brake pads.
New genuine Norton rear rotor, part number 06-1885.
New genuine Norton rear caliper, part number 06-1926.
New genuine Norton rear master cylinder, part number 06-5776.
Genuine Norton rear brake pads.
Braided stainless steel brake lines, stainless steel caliper pistons, and upgraded master cylinders all add up to tremendously improved stopping power over the OEM set-up.
ENGINE BREAK-IN
Fresh oil change after about 500 break-in miles.
Head gasket re-torqued, valves re-adjusted.
New header pipes and mufflers get installed now.
Final break-in consists of performing 'high-speed burn' spark plug checks, so we can perfect the carburetion jetting. Our checking of the spark plug color and developing a yellow tint on the new header pipes proves our jetting is perfect. It looks nice when there is no coloration, clean perfect chrome, but it means the jetting is too rich -- engine power will suffer and spark plugs will foul. Purple coloration is pretty, but it means the jetting is too lean, which will allow the engine to get too hot, and the exhaust valves will become damaged.
Zero-miles speedometer gets installed last.
We'd like to see you put on another 500 fairly easy miles before you start drag-racing your buddies.
Runs strong on pump gas, although we always recommend non-ethanol.
#1 choice: non-ethanol
#2 choice: 87-91 octane, adding Star-Tron gas treatment.
High octane is not necessary, but if you choose to use it, make sure it is free of alcohol. Much of the high octane has alcohol added. Star-Tron will negate the damaging effects of ethanol.
Fresh gas is most important, as there will be less likelihood of water in the gas.
We've built the bike with modern upgrades, while keeping the appearance of the bike very original. Overall improvements over stock = quicker acceleration, faster on top end, with a smoother engine as well.
Watch a cold engine start on y0u tube named "Zap Cycle 1975 MK3 Jan 2024" .. This is a 'cold start', where the mechanic puts his hand on the exhaust header to prove it's cold. He turns on the petcock and tickles the right carb, walks around and tickles the left carb, turns on the key and hits the start button. Vroom. 30 seconds of warm-up and the engine idles smoothly.
May be seen at Zap Leather and Cycle/Zap Cycle in Paynesville MN.
920 W. Main St.
Our retail store is now open only by chance or appointment. call 320-243-3797
Being an online retail store, we have the opportunity to allow payments from Visa, Mastercard, and Discover for a 3% User Fee.