I'm looking for 12-volt, electronic ignition options for a '61 Triumph 5TA that has the original distributor type ignition system.
My preference is for a system that is self-generating such that I can substitute a capacitor for the battery - - - I have a lot of vintage bikes and I try to avoid batteries on everything but the electric start bikes. I'm in the U.S. so MOT inspections don't apply, and the bike won't be ridden at night. But if no battery-less plug-and-play solution exists, having a battery is okay.
I have a 56 Thunderbird with Kirby Rowbotham fitted Pazon EI in the distributor. I run a Vreg regulator with a capacitor fitted. This runs the bike fine, but as I have 55/60 watt headlight I need a small (7AHr) battery, or it dies at tickover. With the standard 35watt bulb its OK. My other bike, more relevant to your post, is a 61 T100A, with 18D2 distributor. I got the EI conversion from Al Osbourne, www.aoservices.co.uk . It is a Boyer MkIV, fitted into the distributor on a backplate, there is a bit of machining to do, but nothing too complicated, which I run on a Boyer Powerbox. My 500 is an off roader, used for Long Distance trials, I have a 35 watt headlight, 5 watt rear light, small horn, brake light. It all runs absolutely fine with no battery. The only thing you have to remember, is to make sure the lights are switched off before starting, but you can get a Boyer Powerbox which only gives power to the lighting circuit once the alternator is producing a certain voltage. AO services website is not the most modern, but if you phone Al, he is very knowledgable, and helpful. Hope this is of use.
When I was looking to fit EI to the Thunderbird, Kirby Rowbotham was the only option I found, in fact he probably still is, as I dont know if Al Osbourne does a kit for a DKX2 distributor. I had to send the distributor away to be machined, and have the EI fitted, this took about 4 weeks, a bit longer than estimated (often the case!) When I did my T100A, last year, I found the Al Osbourne option on the 18D2 distributor, and when I spoke to him, he said he would machine the back plate to what in his experience was about right, it fitted perfectly, so I didnt have to send parts away, and then await their return. Another thing, he advertises the mod as a kit, including coils etc, I didnt require coils as I wanted one double ended coil to save space on my off roader, this wasnt any problem, he just sold me the bits I needed.
As far as I know, it will only produce the higher output at higher revs, certainly higher than tickover. but as with my T100A, its no problem with a 35watt headlight bulb. If you do want better lights, you can get Halogen 35 watt bulbs, and LED tail/brake lights, in - and + earth. www.norbsa02.freeuk.com
A three phase alternator will increase the power produced at low revs over a std single phase alternator, a fresh rotor will also improve output over a 30 odd year old rotor. I run a 3 phase alternator on a Commando with battery and capacitor, if the fuse blows the battery comes out of circuit and the bike runs on the cspacitor and with a 55/60W main bulb it idles fine. I only know the fuse has blown after stopping the engine, when I turn the ignition back on the alternator voltage bulb is off and the bike won;t kickstart but I can bump start it.
The folks at Electrex recommended their new STK102D kit for no-battery applications. The kit appears to include a new alternator, electronic ignition, and coil. The electronic ignition triggers off the alternator, which should be more accurate than a distributor mounted setup.
I ordered the Electrex STK102D kit configured for a battery-less application. My engine is getting rebuilt right now, so installation probably won't happen for another month or two. I'll report back when that happens.