Norton 850 Commando rewire

Corbin seat makes the whole thing look shorter and more agile

The indicator and horn switch: missing bits and full of axle grease…

…now repaired and cleaned up

This object used to be a Boyer electronic ignition box. Understandably, it was replaced

Fitting indicators is a lot more than wires. Here we’re making brackets for the rear ones

Electronic Smiths speedo left; analogue original right

Keith’s Norton Commando 850

Boy, this was an epic job. Keith brought the bike along saying it was hard to start and running sub optimally. It already had a Mikuni carb, so the finger of suspicion hovered over the electricals.

There was also the need for some new indicators, and Keith fancied a Pazon ignition and a pair of Smiths electronic clocks too.

On these later Commandos the weak electrical components are the cheap handlebar switches. New ones are very hard to come by, and the old ones tend to wear and lose vital springs and ball bearings. You can’t replace them because they are integral with the clutch and brake levers. Fortunately I managed to rescue most of the functions on Keith’s with components from my box of dead Japanese switches.

The moribund Boyer ignition was replaced with a shiny new Pazon kit. And the loom went together as smoothly as usual. The snags were the sort of things you find on an old bike: the rear frame loop had fractured, and needed a weld repair at Etto Motorcycles. Then the points backplate screw thread crumbled to swarf, necessitating a helicoil repair. Getting a pair of wires on the neutral switch meant draining the gearbox. And the carb was beginning to bung up with stale fuel. E10 really does play havoc with pilot jets if it gets left for more than a couple of weeks.

And after all that it still ran like rubbish! In fact, it barely started, and sounded like the timing was miles out. The cause? Duff spark plugs. I’d heard that most plugs on eBay now are impossible-to-spot fakes. This was the first time I’ve seen the proof up close. These were brand new B7ES plugs.

I rooted around and found some very old, corroded B8ES replacements. Instant result: it started immediately, and ticked over happily. Every day’s a school day. I will make sure I only buy my plugs from pukka classic shops now.

This is a fabulous bike, with a unique look and a very strong engine. Keith was delighted with the result: “Thank you so much. Your dedication to complete these works is outstanding. I will be promoting you throughout my travels with many like minded motorcyclists.”

Cheers Keith. It was a pleasure.