Upgrading the electrics

Okay so in the last issue we looked at the basic sanity checks and repair techniques for our restored motorcycle’s electrics but before we start plugging things in and switching stuff on with reckless enthusiasm let’s take a step back and see if we can’t

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Almost without exception your bike will run a rectifier and regulator if your generator is an alternator i.e. it delivers AC or alternating current. Your bike’s various systems require DC or direct current, if not very strange things can happen. Back at the plot… a rectifier converts alternating current into direct current and a regulator maintains a set current/voltage. Both perform critical tasks yet they can often fail with age.

The technology used in a 40-yearold regulator or rectifier isn’t quite stone age but it’s not far of it. Unless you are hell bent on producing a 100 point perfect show specimen now is the time to update those two vital components. The good news is that modern solid state automotive electronics are almost bombproof so there’s no need to rely on archaic rareearth metal devices such as selenium rectifiers and the like.

Better still, older bikes are able to run a combination unit such as regulator/rectifier (aka reg/rec) unit which takes up minimal space and works so much more efficiently. And perhaps best of all these modern gizmos are a fraction of the cost of the OEM units.

And it’s not just electrical control systems that have come on in leaps and bounds either. Specialist manufacturers have set up to produce 21st century electronic ignition systems that are light years ahead of the old points and coil systems. Better starting, improved performance and better fuel consumption are all there for the taking. Allied to this some of these aftermarket systems come as part of a generator system which sees a useful extra current capacity being available… modern technology should never be dismissed or ignored when it comes to older motorcycles.

If the bike you’re sorting out is an unknown quantity then it’s very worthwhile looking a little deeper at the electrical systems. Most bikes will be running some form of generator and the vast majority will also have an electric starter. It’s genuinely worthwhile looking at both before simply putting them back into service. Starter motors will almost certainly contain carbon brushes and these have a finite service life; if the brushes are too short then current cannot flow properly. The same applies to generators that utilise brushes. A bit of time invested here could make a disproportionate difference to the enjoying the bike later. If, having followed the manuals, you find there is an issue of fault with either the generator or starter motor help is at hand. Look at our sister titles Classic

Motorcycle Mechanics or Old Bike Mart for the specialists who can sort out 99.9% electrical issues here.

Hopefully you’ll have committed to fitting a brand new battery but what sort are you going to opt for? AGM or Absorbent Glass Mat has made bike batteries more robust than they ever used to be and is definitely worth considering. The same goes for the totally sealed batteries which don’t require a vent tube. MotoBatt offers a huge range of flexible options with two positive and two negative terminals facilitating fitment to almost any classic machine. Finally there’s the lightweight lithium polymer batteries that offer low mass and small physical size.

Finally on the subject of electrics there’s the now ubiquitous LED bulbs for which there seems limitless applications. They have successfully been used on older bikes but with certain qualifications. Not all old bulbs swap out like for like with LEDs; some LED’s may need resistors placed within the appropriate wiring systems and lots of aftermarket LEDs offer unidirectional light beams