SCF1000 cutting out

A

andre

Senior member
Wise men...
I have recently experienced my SFC1000 cutting out occasionally. It has happened while running stationary and while mobile. It just cuts out power totally. When I hit the starter again it just restarts perfectly. Very sure its electrical issue.

Running a DMC2 ignition about 25 years old. Wiring in totally stock condition.

I'm thinking just buy a new ignitech ignition from Red. Any advice on any other simple things to check?

Thanks, Andre
 
the original fuses gave me trouble, sometimes, the lights would be on when idling but off when moving.
a wiggle of the fuses would get them working again,
I checked all the wiring, cleaned as many connections as I could and replaced the fuse box with blade type, and no issues since,
maybe the fuse ?
 
I have, over the years, had something of that sort happen due to a dirty connection in the ignition switch.
With the gearbox in neutral, turn the key 'On', try wiggling the key and see if you can get the green light to flicker.
Remove key and spray a little ACF 50 or WD40 in the keyhole, replace key and give it a good workout.
That may well solve your issue.
Worked for me, for the last 45 years.
 
skinny pinney has a very good point, the torpedo type fuses that are sold now are very poor quality, and they very often do not have the pin point connection that is required and one end of the fuse for installation in the standard Bosch fuse box, one end is as I say an indent in cast brass to locate the very tip of the fuse, the other is held under a brass sheet metal tang, which looks inferior, but usually the problem is the other end, never mind if this is the problem or not, always a good idea to change to a blade type fuse holder, see pic of TOG.
CLEMresize fuses.jpg
 
Wiring in totally stock condition.
Click to expand...
I'd take a careful look at the pick-up (trigger) wiring. The 6 way connector block at the back of the engine crankcase may reveal cracked/brittle insulation which by now will likely be exposing bare wires that short out one or more of the trigger outputs. The same may be true at the trigger end of things under the pickup cover.
If you have the later type DMC which uses an infra-red pickup instead of the original Bosch items, ignore that suggestion! Instead, carefully inspect the wiring on the multi-way connector on the DMC box. Well known failure is for a wire to fracture close to a connector crimp there. And before all that, check you've got a decent earth for the DMC. May be worth checking your reg/rect is working and limiting battery volts to 14.5v or thereabouts too.
 
Rob said:
I'd take a careful look at the pick-up (trigger) wiring. The 6 way connector block at the back of the engine crankcase may reveal cracked/brittle insulation which by now will likely be exposing bare wires that short out one or more of the trigger outputs. The same may be true at the trigger end of things under the pickup cover.
If you have the later type DMC which uses an infra-red pickup instead of the original Bosch items, ignore that suggestion! Instead, carefully inspect the wiring on the multi-way connector on the DMC box. Well known failure is for a wire to fracture close to a connector crimp there. And before all that, check you've got a decent earth for the DMC. May be worth checking your reg/rect is working and limiting battery volts to 14.5v or thereabouts too.
Click to expand...
Check your earth strap from frame to engine I think it bolts onto one of the crankcase breather bolts.
 
Can be several things. I understand the whole electric turns off or is it just the ignition (engine stops working but lights are still on and neutral light, too), please?

if all goes off an on, it can be
-Ignition key wiring
-kill switch
-a fuse contact that just is to bit to wide and makes the fuse "dance" in its seat
-earth connection
-broken or almost broken connection from battery to ignition switch
-9 pin connector melted or corrodet (under the tank unfortunately, on the right side close to the headstock

If it is just the engine cutting out and everything else is still working, check for
-a lose or broken connection on the top of the long connector in the DMC 2
-look under the ignition cover on the left side of the engine for dirt or oil/water; might block the photo-cell
-battery or regulator shot? DMC does not like low or high voltages and starts cutting out below 9V or above 15 or so.

HTH
 
At my SFC 1000 I had an issue with the ignition key wiring, one contact of the connector was corroded.
Regards Andre ;-)
 
A few years ago I bought a new battery which was an AGM type and had the same problem. AGM has about 0,5V more total voltage (more headroom for starting and a stronger spark from the coils).
But I can imagine that in this new situation voltage spikes from the regulator voltage can easy hitting the 14,5V mark and so cutting out the ignition, My one is a DMC 1 blue version so I asked Gijs van Dijk for help and got a type of "voltage lowering device" from him. A small box with maybe a sort of one or two diodes in supply of the 12V connection of the DMC to lower the supply voltage.
After that had never more these problems :-)
grtz and stay safe, René
 
Thanks for the good suggestions guys. I'll check ignition switch, fuses, ign pickup and wires.

I agree with the suggestion on upgrade to the earth. I did that some time back, connecting to the starter mounting flange. 6mm bolt onto breather seemed a bit undersize.

I'm working out of town for a while so it'll have to wait.

Thanks, Andre
 
Laverda1000.de said:
Wouldn't that be a regulator?
Click to expand...
Not quite, although it's a regulator of sorts. I suspect Rene is right that it's just a series of diodes to step the voltage down.

The voltage regulator on the bike is set to around 14V, but that's often too high for the old DMC1 and can cause the ignition to misbehave. My DMC1 did that, and as it got older its maximum voltage threshold gradually decreased. Uwe Witt gave me one of those little voltage reducer devices to put in the power supply wire to the DMC. I think it dropped the voltage down to around 10V, but eventually even that was too much for my ageing ignition. So I replaced the whole system with an Ignitech and one of Red's alternator conversions.
 
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