Oh no! No start after 40 years...

[redfox]

Hi all,
So started the bike up recently, warmed it and changed the engine oil. Not a single problem with my SFC1000 ever. So, today, no start.
Changed the fuel. Nothing.
changed the spark plugs. Nothing.
Took the carbs off and readjusted and cleaned. Nothing.
Filters in tank. Nothing.
sprayed into the on/off switch. Nothing.
Measured the on/off dead man switch. beep. No start.
Tried 1 by 1 each cylinder with the spark plug in the lead on the top cover. Nothing on any cylinder.
Looked at wires and connectors. Just looking. No start.
Looked at the fuses. measured fine. No start.
Okay, so I don't think 3 coils stop working.
My starter spins like crazy. Just won't start.
I run with a MotoWitt Mk. 1 blue ignition box.
I guess it may be dead?
How to test it?

Jacques

 

[Gerald]

IIRC there is a test setting, blue DMC has slide switches. The manual should provide the settings for constant spark. Piet may chime in to provide more details. My DMC 1 stopped working after 36 years, but was accident related.

HTH

 

[redfox]

How to measure if there is power to the coils? Is that at all times, or is it depending of them fireing?
Also, there is full light on the bike, blinkers, rear light, neutral gear, head light, dipped and high beam.
So I take it that the ignition switch is not dead.
Also, all pickups (original ones) are fine, sit where they should. Giver is placed. all looks firm and as it should. On my old RGS I once had a dead wire from a pickup. Dug it out, soldered in new wire and all was good. I don't think that all wires from all coils suddenly die.
So:
Down to I believe power for the coils. So how to test that?
And how to test the Motowitt blue ignition box?
Cheers,
Jacques

 

[redfox]

Thanks Gerald, I will look into that.
I found an old manual of some sort in German of course, in my bookshelf, and it said in the case of no spark at all on any cylinder:
1 power for the computer is not there or
2 test the current 0-12 Volt dc on the primary side of a coil connected. Push the starter and if no pulsating volt, the whole computer is defekt.
I did that nr 2 test and no voltage at all.
I will try to look up the test setting.
Cheers, Jacques

 

[Otto]

At this time every wire on an original pick-up is risk. The original wiring is now to old. I changed last winter for two bike the wiring.
When one spark plug does not works, the DMC stops working at all. He will not run on two cilinders because of the ignition, only because of carburation it can,
Last time I had a problem with the blue box because the hose on the wiring became to hard and the wiring broke because it was too thight.

 

[MotoJouni]

Hello Jacques

1. Check that you get +12V with a multi meter on the ignition coils. Ignition on, but no starting. Should be +12V on all of the connectors.
2. I don't know how your DMC is wired, but there is a bullet type connector somewhere under the seat, if I recall correct. If this is not in place or has any issue, the ignition units would be without electricity. Also a good place to check if there is voltage on this connector. The connector is identified on the diagram with a red ellipse on the attached picture.

-Jouni

 

[redfox]

Right, so I found that encircled connector and it is white/orange. This is where the DMC is tapping into power, and since this goes via the dead man switch, there is power when the switch in “on”. Makes sense.
I also noted that this system runs on fuse 2 “servizi”, and this has power.
So if no wire is broken, there should be 12 Volt at the 3 ignition coils and I then measured that, and there is indeed 13 Volt.
This would mean that all coils gets power supply and in a case of 3 original Bosch ignition boxes, these are fed on the same system, and in my case with the DMC mk 1, it taps power from the same orange/white wire connection, so I measured that and there is supply at leadt in the beginning of the red wire that goes into the DMC box.
So far so good. There should be power all the relevant places.
Cheers,
Jacques

 

[redfox]

I looked carefully at the wires going out from the DMC and they seem in good order.
I still have to find out how to test the DMC box, including the setting for constant spark for test purposes.
Spent 9 hours today at this problem, so will go indoor and relax a bit. Then I will continue tomorrow.
Cheers,
Jacques

 

[Otto]

Do you have these instructions?

 

[redfox]

Hi Otto, I just found it online. I have the German version, but seem to miss a part of it. So I just read the English version now. I saw that dip 4 to be on= test setting. I will follow that tomorrow.
Thanks to everyone so far.
Kind regards,
Jacques

 

[piranha-bro2]

Good luck. Almost certainly the ignition module, whether fried internally or a break in the +ve feed or earth. Can you borrow a DMC box from soemwhere - would have saved you 9 hours of grief