1989 A3ms no spark, lost, advice needed

Hello

I’ve recently purchased a tomos a3ms as a little project. Wanted one for ages and one finally popped up in my area.

I’m having issues trying to get it to spark, electrics isn’t my strongest. I’ve searched the forum for other no spark related topics to see if I can find the answer but unfortunately to no avail.

I’ve bought brand new points, adjusted the timing and also a new condenser. I have power coming from the black wire from the magneto, a new ignition spark plug coil, lead and cap but still no spark. The lights work when I kick it but I know this doesn’t mean much from previous posts I’ve read.

I’ve tried looking at dozens of wiring diagrams but can’t seem to find the right one. I’ve got a brown and blue wire not connected to anything near the speedo, but i can’t work out where they should go from the diagrams I’ve looked at (picture attached) could this be the problem? From what I can see doesn’t look like they connect anywhere. All the lights, speedo etc are all connected up.

If you could point me in a direction on what next to check or turn too that would be a great help.

5D1F22F6-F9D4-4836-967E-69A6A750996B.jpeg

Cheers

Re: 1989 A3ms no spark, lost, advice needed

hi, did you look at this diagram (1988 w turn signals) looks like they connect to the turn signals.

if it were me i'd double check and reset the point gap and timing just to make sure it's at least in the ballpark. (edited)

Re: 1989 A3ms no spark, lost, advice needed

♣Slew Foot♣ /

The negative return ground should be bypassed to the frame and disconnect the killswitch to diagnose. Its the Blublack wire it will stop it from starting if the bulbs and or horn fails.

Re: 1989 A3ms no spark, lost, advice needed

I’ve checked the indicator and it’s already wired up and works, thanks for the wire diagrams. I’ll have another check with the points gap and timing, surely even if the timing was slightly out it would still spark?

Re: 1989 A3ms no spark, lost, advice needed

> ♣Slew Foot♣ Wrote:

> -------------------------------------------------------

> The negative return ground should be bypassed to the frame and

> disconnect the killswitch to diagnose. Its the Blublack wire it will

> stop it from starting if the bulbs and or horn fails.

Sorry buddy but a lot of that went over my head, which one would be the negative return ground?

I’ve checked the bulbs as I know if one of rear lights pop it kills it, they all work

Re: 1989 A3ms no spark, lost, advice needed

♣Slew Foot♣ /

Sometimes the wiring through the frame is frayed going to the taillight it's usually best to bypass the neg ground return. It could be a ceramic resistor in the tail cracked. Its hidden behind the reflector block.

Yours should have the newer casehalve that will take a cdi upgrade. Recomended. You need the 4 mounting pylons some have just three.

The regulator ground is isolated from the rest of the grounds? If it isn't it will blow out bulbs and such if it's all on the same ground it would short it so it wouldn't start bad killswitch would do the same recheck the wiring try to simplify the problem check all the simple stuff spark fuel air ...

Re: 1989 A3ms no spark, lost, advice needed

New points doesn't mean they are clean .

Clean the with brake cleaner and compressed air . Even passing a clean dollar bill between closed points works .

It only takes a fingerprint to foul points .

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