6 Volt Wiring

What to do?

The original loom from my 1971 ST50 is now nearly 40 year old. It has deteriorated and corroded. The outer sheathing has split, and an inital inspection shows that one of the rectifier wires is down to the copper, perhaps the sign of an earlier overload?

The previous owner told me that the ignition switch had failed and the bike had been "hotwired". The bike has not run for 28 years. Experience tells me that there is usually a reason why a bike is taken off the road in the first place. It is then that before you know it the best intentions to fix it ends up in an ebay sale 28 years later! I now strongly suspect that my bike had electrical problems 28 years ago and that this is the underlying reason that it has not run since.

My first choice was replacement wiring loom. A call to David Silver informs me "not available". I can't say that I am suprised but what now?

Option 1: I repair the existing loom myself using parts available from Vehicle Wiring Products Ltd.
Option 2: I have the existing loom professionally rebuilt.
Option 3: I see if I can find a non-genuine replacement loom.
Option 4: I convert the bike to 12 volt electrics

From my perspective each of the above has pros & cons. I am happy to share these if anyone is interested? I expect that this is a dilema/situation that many of you have faced and I would welcome your thoughts and comments.

HI THERE
In my limited experience the 12 volt option is the more sensible but in my case finding a suitable magneto/cdi conversion was my stumbling block. Try contacting OOracing they helped me out you need to speak to Adrian. I got my 6 volt sorted but the lighting issues still make me a little wary now the dark nights are closing in
regards Tufty

Hi My opinion,
1. Keep the 6volt electrics- unless your after a brighter headlight, 6 volt system is fine.
2. Get a copy of the original wiring diagram and remove your old loom. Lay your loom out on a bench and carefully unwrap.
Check the colours and wires against your diagram and make up a new loom. It's an easy job, the hardest part is to source the wires in original colours.
3. Buy a new loom from http://www.dratv.com/noname157.html thesea are virtually the same as your bikes loom.

4. Try the Rovaza (holland) aftermarket harness see: http://www.rovaza.com/product/Main+wire ... x%5CST+6-V you can call these guys to confirm it's right, they are helpful.

good luck

Monkeybike UK sell 12v Wiring Looms and a few other bits you may need. Delivery charges can be a bit steep but I have spent a fair bit of money with them and they are pretty good.

Link: http://www.monkeybike.co.uk/acatalog/El ... ition.html

If I was restoring a bike not to the original specification I would go down the 12v path. My ST70 is 6v and the lights etc are shockingly bad.

Many thanks for all your comments and help.

I am going to mull this over further but my current thinking goes something like this:

When I bought the bike I particularly wanted an early 70's model. I did look at a number of 12 volt models from the 80's and I now think that I should have bought one of those if 12 volt electrics was particularly important to me. It isn't so I will probably stick with the 6 volt electrics.

My preference would be to rebuild the original loom myself. However, this will definately cause grief with my wife. She will not appreciate the smells of flux and solder or the mess it will create and the amount of my time that it will take.

The solution may therefore be to buy a replacement loom for now and rebuild the original loom over a period of time when the wife is out. This is a skill that I have developed over the years. I used to own a Suzuki GT750 two stroke that needed a baffle clean that required use of the cooker (unfortunately I do not have gas or a bunsen burner in my shed). Needless to say, this is not the sort of work best undertaken in the wife's presence. Further, she was actually very pleased when I upgraded the kitchen extractor fan to a twin fan model.

I'd keep the 6v loom myself, as it is part of the nostalgics.
I'd simply buy a replacement loom (either Honda or replica) or create one myself.
If you have the schematics, it's a pretty easy job.

Unlike nittokid says, the best thing about the 12v electrics is the reability of the ignition.
Simply because this gives you the chance to have a reliable electronic ignition system.
(no more checking and adjusting the ignition timing / that said, I fancy this kind of old-school engine tuning!)
The easiest and cheapest way is to fit a 12v Jingcheng ignition. (6v crank fitting, 12v output) or an expensive (but performance) solution is a Kitaco,... 12v rotor (again, for a 6v crank)
This can only be done if you have an L-type crank!!! (so no Hitachi ignition systems! Because you'll have to place a conversion part over your crank)
Also, you can fit in a 12v maintance-free battery + LED/halogen bulbs with higher outpot and longer lifespan.

If you're searching overseas for replacement parts, there are Belgian stores which offer better quality and better priced parts as rovaza does.

Hi guys
why not just buy a complete engine Jingcheng or what ever and keep the old engine in a box in the shed these are getting more difficult to find these days.

Yeah, the chinese engine is an option, great for a runabout, but it's not quite right in a honda
I've had a lot of success with just re-doing the loom, takes a couple of hours.
Also, adding a regulator $15USD and a 6V CDI with high output lighting coil $110USD.
The coil and CDI take about 1/2 an hour to install. Add a sealed battery or battery eliminator and you never need to worry about the electrics again.

True.
If you're riding a Honda, you shouldn't settle for Chinese quality.
These Honda engines are bulletproof when maintained right.

6v to 12v ignitions sell used, but in perfect condition around 15 - 50€ here.

I bought a pattern 6V wiring harness from CMSNL a few weeks ago, I haven't fitted it yet but the quality is spot on and it looks ok. Apparently there are some cheap ones around that have questionable build quality but this one looks alright.
I was an electrician and building a harness posed no fears for me (i've done it for other bikes including my wife's old Royal Enfield and my old Laverda Jota) but by the time you have sourced all the correct coloured wires in the correct size and the connectors (including the block connector) it was more hassle than it was worth. It would probably cost in if you were building a few harnesses but for just one, I couldn't be bothered.