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Installing an Alton Norton Commando Electric Starter

The Norton Commando is one of the most popular classic motorcycles ever made — and they made lots of them, an estimated 60,000 over an almost 10-year life span. Endowed with excellent handling and a torquey, train-pulling twin, they were the Superbike of their day.

Although electric starting was planned at least by 1970, the first electric-start Commando didn’t appear until 1975, the last year of full production. That means that most Commandos, whether 750 or 850, were kickstart only. The Norton lump can be a challenge to kick over, and as the Norton faithful aged, the market for an electric-start conversion grew. There are now several available, including the one from Alton in France that we installed in our subject 1974 Norton Commando 850 MkII.

Applicable to pre-1975 750 and 850 Commandos (except early Fastbacks with the ignition at the rear of the timing cover), the Alton kit uses the stock chain-driven primary and can be used with many belt-drive conversions.

This is a comprehensive and extremely well-designed conversion. The replacement inner primary cover carrying the small but powerful electric starter is beautifully cast and nicely machined. The starter sprag clutch and drive setup seems very robust, and the Alton alternator, rated at a maximum output of 150 watts and 90-95 watts at cruising speed, should provide ample charging. The kit is available for either positive or negative ground systems.

You’ll need a higher output battery. U.S. distributor The Classic Bike Experience in Essex, Vermont, where we sourced our Alton starter, suggests an Interstate FAYTX20HL sealed lead-acid battery (pre-1971 bikes require a smaller battery; call CBE for options). We found one locally for $85. CBE also suggests replacing the crankshaft seal. It’s cheap (typically only $2 or $3) and easy to replace while the primary cover is off. You’ll note that we did not, however, as the seal had been replaced just a few months earlier during a clutch overhaul.

The kit does not include an outer primary case locating dowel. We had to heat the stock case quite hot to break one of the dowels free, and it was a slightly loose fit in the Alton cover, requiring a dab of RTV sealant to hold it in place. New ones are cheap (about $2.50), but this is one item we think should be included with the kit. We’d also suggest having new woodruff keys ($7 to $10) and a new clutch hub locking tab (about $1) on hand. You’ll need a puller for the crankshaft sprocket, a clutch hub locking tool, a clutch spring compressor, and a torque wrench.

On post-1971 Commandos the stock switchgear has an unused button, usually the upper right side. Legend says this was included for a proposed starter. You’ll have to remove the gas tank, then locate the white/red wire coming out of the switchgear, which terminates in one of the connecting blocks on the frame. It’s basically plug and play, but it’s a good idea to clean the switch first. Pre- ’71 bikes require a separate switch.

This is a detailed job. Give yourself a full weekend and have a Norton service manual on hand; it will help immensely during disassembly. The Alton kit comes with a comprehensive installation guide, with photos to aid installation, and it stresses important points like properly setting the alternator stator air gap and making sure everything is absolutely correct before you attempt to start the engine the first time.

And when you do, you’ll probably be as thrilled as we were. The Alton starter spins the Norton engine over easily, providing effortless, reliable starting — without kicking. As a further bonus, when you order your kit from CBE it includes a nice CBE pint glass (gotta have a beer to celebrate when you’re done!) and a two-year membership to the International Norton Owners Association.

The kit retails for $2,450. That’s hardly an inconsequential sum, but if you want your Norton to start at the touch of a button, we think the Alton kit’s quality design and straightforward installation with no permanent alterations make it a good value.

1. Disconnect and remove the battery. Remove the left footpeg and brake pedal assembly. Place a drain pan under the primary cover. Remove the center holding bolt, then the primary cover. Use a rubber mallet to shock the cover free.

2. Remove the three nuts securing the alternator stator. Remove the stator. Wedge the plastic block supplied in the kit between the primary chain and the crankshaft sprocket to lock the crankshaft, then remove the rotor nut. Using flat tire irons pressed against the back side, leverage the rotor free. Remove the rotor, the woodruff key and any shims.

3. Remove the clutch adjusting screw, then the clutch diaphragm and clutch plates. Fold back the clutch hub nut washer tab. Lock the clutch hub and remove the clutch hub nut. An air impact wrench will remove the nut without having to lock the clutch hub.

4. Using a puller, break the crankshaft sprocket from its taper. Protect the crankshaft threads by placing a washer between the puller and the crankshaft stub. The sprocket can be stubborn to remove. Lightly shock the puller bolt with an air impact wrench or rap it lightly with a hammer to break it free.

5. Once the sprocket is released from its taper, remove the sprocket, clutch drum and chain as a set. Remove the crankshaft woodruff key. Remove the shims and the clutch locating collar on the transmission mainshaft.

6. Trace and disconnect alternator wires at the main harness. Pry back the tab washers on the three bolts securing the primary cover to the engine. Remove the bolts, washers and the cover. Clean the engine case. Remove the primary cover central locating stud and fit the new Alton stud finger tight.

7. Clean the engine case. Remove the primary cover central locating stud and fit the new Alton stud finger tight. With a straight edge against the engine case, check the distance between the straight edge and the stud’s locating flat. It must be 22mm. Shim if necessary.

8. Install the Alton inner primary cover and lightly tighten the securing bolts with washers. There’s a slim chance the new bolts could contact the crankshaft counterweight. We positioned the crankshaft and measured the distance to possible interference against the length of the bolts and found ample clearance.

9. Even so, with the Alton primary case in position we slowly turned the engine over to ensure the crankshaft counterweight did not contact the securing bolts. If it does, you have to shorten the securing bolts.

10. Remove the primary case. Apply blue Loctite to the new central primary case stud threads and tighten it fully with the new coupling nut. Make sure the crankcase mating surface is clean and apply a film of gasket sealant. We used ThreeBond Gray.

11. Reinstall the Alton primary assembly. Alton suggests using Loctite on the securing bolts. We opted for Permatex Copper RTV sealant to ensure no oil migration through the threads, a somewhat common problem on Commando engines.

12. Install the clutch locating collar on the transmission mainshaft with the cupped side facing the transmission, followed by the shims. Turn the engine so the crankshaft sprocket keyway is at 12 o’clock and install the woodruff key.

13. Install the clutch drum, crankshaft sprocket and primary chain as a set. Install the clutch hub tab washer. Apply blue Loctite to the mainshaft threads, then the clutch securing nut. Lock the clutch drum and torque the nut to 40ft/lb. Fold two of the tab washer flats to lock the nut.

14. Install the clutch plates, clutch diaphragm and circlip. Loosely install the clutch adjusting screw and nut. Turn the engine over to bring the alternator rotor keyway slot to 12 o’clock.

15. Install the woodruff key and check the fit of the Alton sprag clutch assembly on the crankshaft. It should be a sliding fit. If not, polish the crankshaft with fine emory cloth. If it catches on the woodruff key, carefully file the key as necessary to achieve a smooth sliding fit.

16. Remove the sprag clutch. Remove the sprag clutch drive gear from the primary cover. Pull it straight out, then up to clear the primary chain. Remove the woodruff key, install the sprag clutch spacer stepped end out, then reinstall the woodruff key.

17. Install the sprag clutch, the sprag clutch drive gear and chain as a set. An extra set of hands helps to ensure the woodruff key stays in place while positioning the drive gear and pushing the sprag clutch onto the crankshaft and the drive gear into the primary case.

18. Put the rotor nut on hand tight. Position the drive gear steady plate, passing the bushed end over the end of the sprag clutch drive gear.

19. Apply blue Loctite to the central shouldered bolt and tighten lightly. Apply blue Loctite to the three steady plate screws and tighten. Tighten the shouldered bolt.

20. Remove the rotor nut and apply blue Loctite to the crankshaft threads. Lock the crankshaft using the supplied plastic block and tighten the rotor nut to 60ft/lb.

21. Install the alternator stator. Fit two of the three screws loosely. Insert the supplied plastic shims between the windings and the rotor to set the air gap. If necessary, adjust the air gap by moving the stator sideways. Once set, tighten the two screws, then install and tighten the third screw.

22. Ensure the air gap clearance is consistent. We marked the rotor face with a black felt pen and checked the air gap every 120 degrees of engine rotation. Connect the stator wires to the two wires in the primary case. It doesn’t matter which goes where.

23. Connect the alternator wires to the factory harness. It doesn’t matter which goes where. Locate the factory white/red starter switch wire and connect it to the supplied jumper wire.

24. Install the battery and the starter relay. Connect the starter switch jumper wire to the spade connector off the relay. Bolt the relay ground wire to the frame. Connect the starter motor cable and the relay to the battery cable. Connect the negative and positive battery cables.

25. Install the new primary case rubber seal (trim as needed) with the joint at the top. Remove a locating dowel from the original primary case and install it in the Alton. Ours was a loose fit. We secured it with RTV sealant.

26. Adjust the free play in the clutch and lock the adjusting screw nut. If it won’t adjust properly, remove the inspection cover above the kickstarter for the clutch operating lever and confirm the lever is in place. If it has slipped out of place, loosen the clutch adjusting screw, put the lever in place and readjust the clutch free play.

27. Install the outer cover and add 200cc of 20w/50 motorcycle oil or ATF. Avoid most automotive oils as they are loaded with friction modifiers. Test the starter with plugs out. Install the plugs, test again, then start up and enjoy!

Published on Apr 10, 2018

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