Dynamo output

From my reading, the output is thermally limited because of the heat generated at the brushes. The regulator could be adjusted higher,  then the commutator would cook itself. The brushes carry the output power unlike a car alternator where the brushes only carry the low power field current.

An alton alternator might help but the products reputation is unknow by me.

Fit led bulbs, same light output for less watts needed. 

6  volt LED replacement bulb from Paul Goff's classic motorcycle parts transformed my dynamo 99 lighting. Also he does a good stop/tail conversion LED and 6v trafficator kit. Good service. Do make sure you have good earthing as LEDs need that.

First I suggest you check out your dynamo-what power is it supposed to produce? What power is it producing? What power are you using?

The Lucas dynamo output for the Lucas E3L and E3LM and the alternators up to RM15 are about the same - at 10 amps.  This gives a theoretical maximum of 60 Watts at 6 Volts.  However this is at about 5000 r.p.m or higher.  At 2000 r.p.m you’ll get around 50 watts at 6 Volts - if you’re lucky.  This assumes good connections everywhere with minimal bullet connector joints and the generator as new.  At tickover speeds a headlamp bulb will be dimmer and drawing power from the battery – but hey – that’s what it’s there for!  You can’t expect a balanced input-output from our old nails!

For us Dinosaurs who are sticking to 6 Volt systems, it’s a problem trying to get more ‘smoke’ through the wires.  One of the best ways to achieve this is to have a decent “earth” connection to the extremities.  This means running dedicated earth wires to the tail lights and headlights and not relying on the frame or tinware as conductors with high resistance.  One way is to buy an earth block (e.g. you can get 4-way or 6-way from Screwfix), fix it somewhere out of sight, but close to the battery, and take a short wire suitable for at least 10 amps (the bigger, the better) from the battery.  Then you connect wires from the earth block in a radial fashion.  Copper wires/cables are obviously much better conductors than steel.  I learnt this from my Dad, who was an auto-electrician (as well as a domestic one) in the 1950s.  One of the vehicles he regularly worked on was the Mighty Antar Tank Transporter – a monster.  Dedicated "earths" rather than chassis "earths" is always best.

Changing to LEDs is another way of getting more for less, but expensive.  It could depend on how much night-riding you intend to do.  As I was a rider in the 1960s and 1970s I’m OK with the light levels we had then – even more by using a halogen headlight.  I might extend to LEDs for the pilot and speedo bulbs.

I would change the tail and speedo bulbs for leds saving about 8w and keep the filament headlignt bulbs as they have better beam patterns.

Paul