Tomos A3 no spark (points ignition)

I'm having trouble with my 1986 tomos A3, it's day 2 and I've spent hours trying to trouble shoot this. I'm using this wiring diagram because it's basically exactly like mine:

I'm using an OEM CEV coil so the tail lights and magneto ground are tied to the side screw. I should also mention I had the moped in "RUN" and did check that the connections on the switches were good and clean. I have a new spark plug and cap. I'm pretty sure I set the points within reasonable accuracy (enough to get spark I would imagine).

- There is a new condenser, new points and new coil for the ignition. I've tested all these and they are soldered properly and working, no spark

- I know this model has particular trouble with the tail lights causing shorts and the no spark problem, but I tested the rear bulbs and they're ok. No spark

- I grounded the blue wire that comes out of the magneto and leads to the tail lights, still no spark

- I also grounded the brown and grey/green wires that lead from the break buttons to the tail lights, nothing yet again

So first of all, does it look like I've attached things properly (from what you can see at least) and is the coil set up properly?

Second, am I grounding the suspicious tail light wires properly? I tried only grounding the brown wire and connecting the three grey wires together and also just grounding all of them

Third is there something obvious that I missed? I've been doing this so long that I probably missed something and would love a 2nd set of eyes.

Any advice would be awesome!


Re: Tomos A3 no spark (points ignition)

Patrick Keaton /

The coil picture was taken in not enough light,so it can not been seen if it is set up right or not.The other picture with all the wires was taken with not enough light and is out of focus,so it is hard to tell what is what.Grounding the brake light wires might be a problem,so try connecting them together or leaving them a part.Did you check the breaker points with an ohm meter before installing. I seen at least one new breaker points have a haze on the contacts that had to be filled of with a disposable finger nail file.

Re: Tomos A3 no spark (points ignition)

Ok, here are some pics with better lighting. Also, I tried filing down the points but nothing changed. And I tried to ground the break wires AND also I tried it with the break wires grounded (the grey with a green stripe wires) while grounding just the brown horn wire (as per the diagram the brown wire is supposed to be ground).

I did check the points with an ohm meter, they seem to be working and like I mentioned I set the points gap and timing (to the best of my ability).

Ps on this pic, the black wire hanging from the coil is just the spark plug wire. I guess I should have wrote that on the pic. And the pic file is too big, so here's an imgur link

Re: Tomos A3 no spark (points ignition)

Take the blue wire where it comes out of the magneto and goes into the little wiring block and ground that to bare metal on the chassis or the engine block. Do you have spark now?

Re: Tomos A3 no spark (points ignition)

That's what I was doing originally and it didn't give me spark. Mind you, the cables in this picture were lose:

So what I had to do was connect the three grey/green ones together and ground the brown one to bare metal, still no spark.

Seriously at a loss with what to do. All the components were tested and work too

Re: Tomos A3 no spark (points ignition)

Okay,one thing that you need to do is check that the wire that goes to the kill switch is NOT grounded.That happens a lot.......the switch lets the wire ground out even when it is in `run'. Trace that wire back to make sure it hasn't grounded on its way to the kill switch. don-ohio (:^)

Re: Tomos A3 no spark (points ignition)

Ok, using this diagram.

Do you mean the brown wire should not be grounded or the black wire? The black wire goes from the magneto and grounds to the coil, then feeds out to the kill switch. From what I can tell they both look like grounds to me basically, what do I do again?

Re: Tomos A3 no spark (points ignition)

Make sure the black wire isn't grounded. don-ohio

Re: Tomos A3 no spark (points ignition)

I still don't get what you mean. The black wire goes out of the magneto and from the wiring diagrams should be attached to the side of the coil (which is ground). From there it goes to the rest of the bike and the kill switch. Do you mean that I shouldn't connect the black wire to the coil ground? does it connect to the bottom coil instead (where the two flat head screws bolt it onto the frame)? I'm not sure I have the wires set in the right place on the coil:


- I've grounded the blue wire that comes out of the magnito instead of screwing it into the terminal block, no spark

- connected the grey/green wires (that connect from the break switch to the tail lights) to close their loop, no spark

- checked the parts and they all work (0 ohm reading on multi-meter)

Re: Tomos A3 no spark (points ignition)

The HT ignition coil has two terminals, the black wire runs from the magneto to the coil, and then to the kill switch, the other terminal on the kill switch goes to ground. This side is only grounded when the switch is in the off position (will not spark). The other terminal of the coil is grounded to the chassis. This means that you can run the black wire from the magneto directly to the ht coil terminal and ground the other terminal for testing. Alternatively you can disconnect the black wire from the magneto, and check the wire on the harness that it connects to for continuity to the chassis. You should have no continuity with the switch in the ON position, and continuity with the switch in the off position.

Simplified, for spark you simply need to run the black wire to one side of the ht ignition coil, ground the other side of the coil, ground the blue magneto wire, and the yellow wire shouldn't matter, it can be isolated.

Re: Tomos A3 no spark (points ignition)

When you say one side of the ignition coil what side do you mean? Theres the side that has a bolt, from what I remember reading that is the ground. Then there are the two spots where the coil bolts to the frame, I dont know if they're live.

I think my no spark has to do with me not knowing where to attach wires to the coil, I cant seem to find much information about this online either. Can someone use this picture to just tell me what colors go where?

Ps. I left both black and blue wires grounded to the side coil bolt cuz it was easy to put on and off.

PPS. How important is timing the points for spark? I tried to do it, but have no idea if it's been done right

Re: Tomos A3 no spark (points ignition)

I got spark! Thanks everyone for your helpful advice.

The problem:

Like MopedGarmy and Don Ruggles suggested, I made sure that my black wire was on the first coil. I didn't know, but the first coil is the one at the top and the side screw on a CEV 6309 coil is to attach an ignition wire (in my case the black one) to the first coil. The tail light wire (in my case, it was blue) attached to a bottom mounting screw for the coil, which grounds to the chassis.

So happy, thanks again!

Re: Tomos A3 no spark (points ignition)

hey can you take a picture of the final set up - same as last photo but with whatever the right wiring is? i’m thinking i might’ve done the same thing but i’m stilll lost

Re: Tomos A3 no spark (points ignition)

> adam porth Wrote:

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

> hey can you take a picture of the final set up - same as last photo but

> with whatever the right wiring is? i’m thinking i might’ve done the same

> thing but i’m stilll lost

This a 4 year old thread . You might be waiting a while for the response you want .

Re: Tomos A3 no spark (points ignition)



Re: Tomos A3 no spark (points ignition)

haaaaa oops. yeah i found that colorful drawing and it saved the day. thanks though!

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