No spark

Hi all, i have no spark and i need to know im earthing the right points.
I have the ignition lock mounted through the frame( on bare metal)
Ignition coil is mounted correctly under fuel tank(again on a good surface).
Does anyone know where else on the loom has to be earthed to get a spark? (ive been told headlight or taillight?) sound right??
Oh and i do have a good spark at points.

Any help would be much appreciated.
Dan

Hi Dan,

There is an earth point on the tail light. If you've recently had it resprayed you will need to ensure it touches the bare metal.

You're correct in that the other earth points are under the tank (on that little plate) and the ignition.
Hope this helps.

James

Brilliant, thanks for the reply james.
Ive got the paintjob in the pipeline, but is bare metal at the mo.
It is a rolling chassis but ive mounted the motor and im just trying to get a spark
Without wiring all the electrics!

So if i earth the ignition lock, the ignition coil and fit and wire the tail and stop light unit and also earth that, technically I should get a spark??
Thanks, Dan.

Dan, I'm not sure I understood it right,
but if you see a spark between the points, it means your condensator is ruined...

In short, green is always the earthing on your wir loom, so if you check the wiring diagram, it's easy to spot the earthing points.

Earthing of the headlight, horn, tail light,... does not have to be connected to get the ignition right.
Cable loom connection and coil earthing should do the trick.

Cheers!

Oh blimey, my bad then mate, so spark at points is bad?
Basically i mounted the motor and wired the loom at the harness clip from
generator up to ignition switch and also the ignition coil.

And with the ignition off i had no spark at points, and with it on i had a spark at the points...
Does that sound like condensator in your opinion?

And if so, is it a tricky change?

Thanks for the help.

Yes, you'll need to change the condensator.
It is not too hard to do so, but here are some tips and required tools:
- make sure you buy the right brand of condensator, and the right height! There are 4 brands, 2 different heights. They are always marked, mostly on the bottom.
- You will need to solder 3 wires to the condensator. It is very important that the condensator doesn't get hot!!! It doesn't like heat so watch out when soldering.
- If your points are burnt (easy to notice on the surfaces) replace them, it's a quick job and makes a lot of difference. Again, buy the correct brand and don't forget to clean the points as they have grease on them from the factory. No need to solder here.

Good luck!
Any questions, I'll be happy to help you if I can...

Thats very helpful thanks,
Just so i know, the condenser is under the generator flywheel right?
And do i need any special tool to get that off?
I noticed there is an F and a T etched into the side
Of the flywheel, does that mean is has to go on
Aligned for timing etc? Will i use the number on the condenser
To track a new one down?
And finally if the points have seen better days is it a new contact-
Breaker i need? (bike hasnt been fired for 21 years) :/

Sorry for 21 questions, just like to understand how things work,
Dan

forget the condensor etc if when your points are closed and you try to open them with a screwdriver etc(ignition on ) and they give a spark..I would always go for the cheapest option 1st ..that is the ht lead from the coil to test this take off the spark plug cap (unscrew it) and put the ht lead very close to the engine then kick it over (if you see a spark tracking to the engine) then its either your spark plug cap or the spark plug...if no spark is there then replace the ht lead (around £3 )try again with the new lead if you get a tracking spark from the ht lead then place the plug cap back on the ht lead and try the plug to see if it sparks....if no spark at the plug replace the spark plug cap ( try again) with the new cap fitted to the spark plug..post your reply after trying what I have said and I will take you to the next step...

Great i will give this a go tomorrow, i actually have a new ignition
Coil so ill change it and let you know how it goes. Cheers

danny-st wrote:Just so i know, the condenser is under the generator flywheel right?

Yes, at the right side on the plate

danny-st wrote:And do i need any special tool to get that off?

You need a flywheel puller. That's all.

danny-st wrote:I noticed there is an F and a T etched into the side
Of the flywheel, does that mean is has to go on aligned for timing etc?

F (Fire) is for setting the ignition timing.
T (Time) is for setting the valve timing.
The points have to start opening right on or little before the 'F' mark when turning the flywheel (counterclockwise!)

danny-st wrote:Will i use the number on the condenser
To track a new one down?
And finally if the points have seen better days is it a new contact-
Breaker i need? (bike hasnt been fired for 21 years) :/

What flywheel brand and type have you got?
I assume a flat Hitachi type? (No retarding / advancing mechanism)
When you know this, it's enough to be able to order the right parts.

decca wrote:forget the condensor etc if when your points are closed and you try to open them with a screwdriver etc(ignition on ) and they give a spark..I would always go for the cheapest option 1st ..that is the ht lead from the coil to test this take off the spark plug cap (unscrew it) and put the ht lead very close to the engine then kick it over (if you see a spark tracking to the engine) then its either your spark plug cap or the spark plug...if no spark is there then replace the ht lead (around £3 )try again with the new lead if you get a tracking spark from the ht lead then place the plug cap back on the ht lead and try the plug to see if it sparks....if no spark at the plug replace the spark plug cap ( try again) with the new cap fitted to the spark plug..post your reply after trying what I have said and I will take you to the next step...

Not sure I understood the post correctly, because of the lack of punctuation marks and my English knowledge.
The way of checking the spark plug cap is correct.
But... first things first. Sparks between the points is ALWAYS a sign of a bronken condensator.
And... a broken condensator ALWAYS ruines you points.
So there's no point in checking the wiring as long as the basics aren't working correctly.
These little parts only cost a few pounds and make a huge diference for these old 6v ignitions.
The lead and coil can be easily checked by measuring the resistance (Ohm) without having to go to the trouble of replacing them (and buying unneeded new parts).
Also, on old (rusty) bikes it's more likely there's an earthing issue. Again, easy to measure.