Honda wiring

have got a ST70 with an electrical fault, purchased as a non runner but has been completely rebuilt, checking the wiring with a Honda diagram, nothing matches up, at the generator I have 5 wires in the harness, blue, red, green, green/red trace/black...have no spark at the point, also how does one get to the wiring on the ignition switch, and do you have to remove the fuel tank to gain access to the coil..
some bright spark out there must have the answer... with hope and thanks oldanf

Welcome to the site Tony!

I only have limited knowledge of the wiring system on the ST70 even though I re-wired my bike during the semi-restoration. Firstly, have you seen this diagram: http://www.st70.net/files/st70_6v_uk_wiring_diagram.jpg

That diagram will help massively (providing you have a 6 volt machine). It has been a while (2+ years) since I last saw the physical wiring of my bike so apologies if any of the information I provide isn't that accurate...

Has the frame been resprayed? If so, remember there are 3 earthing points on the bike. If you haven't got it correctly earthed then you won't get a spark. The earthing points are the ignition lock (the lock must touch the bare metal of the frame), the plate in which the coil is attached to (under the fuel tank), and I forget where the last one is (it's either on the headlight or the rear brake light) - sorry can't remember but I'm sure someone will be along soon to advise correctly!

To get to the wiring on the ignition you can remove the actual lock unit, you will need a special locking tool or some mole grips will work... be careful not to damage the paint! To reach behind the lock you will need to remove the fuel tank. To get to the coil you will need to drop the engine I'm afraid... it's mounted under a plate which sits under the fuel tank. For easy access you could probably remove both as unless you have small hands it's tricky to reach.

Hope this helps!

James

HI GUYS
I HAVE LOOKED AT AL MY 6 VOLT DRAWINGS AND CANT FIND THIS COLOUR MATCH SO I THINK IT IS A REPRO LOOM THE SAME AS ON MY 12 VOLT DAX
I FOUND A GROUND PROBLEM ON MY COIL INITIALLY AND JAMES IS CORRECT YOU NEED PERFECT EARTH POINTS
REGARDS TUFTY

tonysims wrote:blue, red, green, green/red trace/black...

OT 6v:
Green = battery (charging)
Green/red = neutral switch light
Black = ignition (coil)
---
Yellow: light
Pink: unused

NT 12v:
Yellow= Light
White = battery (charging)
Green = earthing
Black Red = CDI
Blue/White = Pulse CDI
Green/Red = neutral switch light


I'd suggest you to check the following:
- is there a CDI in youre wire loom?
- Original ignition or aftermarket (6v / 12v / 6v cdi)
- Original or aftermarket wire loom (check the condition of the plastics, colour codes of both ighition wires an cable loom)
- If an non-original 6v ignition has been fit, it's possible someone has used some wrong coloured wires to connect it to the existing wire loom. Therefor, check the colours further in the loom as well.
- After having sorted out the wires, check the condition and settings of the ignition / CDI / points / condensor / coil / spark plug / earthing!!!.

I would like to thank everyone who answered my plea for help with my wiring problem..
Only been in the st 70 club for one day, and must say I am very impressed by the number of people who took the trouble to reply.
With thanks to you all tony sims

Hows the frame been painted? powder coated or painted coz i think james will be right a bad earth!! Try a muti-meter on igntion switch and earth on battery to see if theres a good earth regards lee