25DB Ignition Lock.

[Frank]

I've just bought a 25DB road bike. It has the ignition lock on the right hand crankcase top, and the previous owner said he had lost the key and so had wired it direct. He had, of course, but this means that every time I use it, I have to disconnect the battery to avoid draining it. I soon had the lock out in order to take it to a locksmith for decoding, but found a snag. I'm not sure what it should look like under the engine cover, but there seems to be parts missing. The lock barrel is there, held in place by a large nut. Under that is a spring which butts up against a kind of crossbar held on by a screw. At either end of the crossbar is a little spring loaded plunger, and nothing else. I've got the manual but the wiring diagram isn't a lot of help. Any ideas, please, anyone on what to do - source the missing bits; go for a new complete lock (but where from????).

Thanks in advance,

Frank

[merlin]

You can get a replacement from Villiers Services as I did for my Greeves East Coaster also in my case the switch only operate across the points and thus does not affect the battery,but as always I could be wrong.
Regards,
Merlin.

[Frank]

Thanks

Merlin,

Thanks for the very prompt reply and the info. I'll get on to them in the morning and get one ordered. I noticed that on the wiring diagram the switch seems to operate on the points, but when I connect up the battery I can hear a definite click from the coils; also the battery runs flat when I leave it connected, which led me to suspect that the coils were draining it. Bottom line, I suppose, is that when somebody else has been fiddling about with a bike, the only sure way is to start from scratch, and really sort out the wiring.

Thanks again,

Frank

[merlin]

From what I understand there are two ways of wiring the system.
1/ You just use the power from the magneto(as mine)b....r to start sometimes.
2/ Wired as a normal coil ignition.
As you say who has meddled with the wiring?
Regards
Merlin

[John Wakefield]

The switch only earths out the magneto and has no effect on the battery unless someone has modified the bike to battery coil ignition. Not standard Greeves practice. The switch therefore has little real use other than to stop the engine if the throttle jams etc. It should not be relied on as a security device.

[Frank]

Thanks

Thanks for this new piece of information, John. Although as you say, the switch cannot be relied upon as a security device, the fact that it is there, and not working on my bike, is incentive enough to get me going. I'm one of those people who can't stand to see a newspaper folded the wrong way round, or a twisted telephone wire, so a non-working switch is like red rag to a bull.

A preliminary look over the wiring reveals that the (or maybe "a") previous owner has had a good fiddle with it. This is the first time I've come across an earth wire in blue and white. The only answer here is to get the switch and then go through the whole loom with my Avometer before trusting any of it.

Frank

[John Wakefield]

Frank the worrying thing is why your battery is discharging, I cannot see how the switch can be used as an ignition switch with a battery coil set up as it is a single pole earthing switch (like a horn push). Maybe the battery loss is not to do with ignition but a faulty rectifier, or other short. As you say you need to get the Avo out & make some checks.

[Frank]

Agree

Yes, John, I'm puzzled about this. I shan't be using the bike for a short while until I've checked out every inch of the wiring. There is something odd going on. Rat's nest wiring, which I've observed under the seat, often reveals a rat.

Frank

[Frank]

Here we go....

...the earth terminal on the rectifier is connected to the negative side of the battery, for starters. There are also earths all over the place, and the oddest array of bits of different coloured wire under the seat that I've ever seen. I'm beginning to think that the easiest solution here is to fit a new harness and have done with it.

[Brian Thompson]

25DB Ignition Lock.

Frank....you've obviously never seen a classic italian bike wiring 'system' then...!

Welcome to the forum (and to the club!), and hope you get it all sorted ok.

As this thread is developing I'm going to move it to the 'Road Bikes' area. Hope that's ok, and thanks for posting it Frank.

Brian.

[Frank]

At last

I've got the bike sorted and running very nicely. The previous owner had had a field day with the wiring and it has taken me a few days to sort it out (slowed down by a nasty gash on the hand from a sharp bit. Wife said the usual thing, "What did you do that for?" I gave the usual answer, "To see if it hurt."...... It does.)

The points were badly pitted, and there was a lot of sparking which led me to test the condensers. They were just about responding, so I took the decision to renew points and condensers. At the same time I tidied up some very nasty wiring under the offside cover and fitted the new ignition switch across the points. The result was an instant start and a very stable and pleasant tick-over coupled to a good take off on the throttle. Such a difference from the lumpy beast of last week. Just in time for the nice weather, too.

Thanks to all who have contributed. As a newcomer, you can imagine how it feels to have some really knowledgeable people to call on.

Best wishes, and thanks again.

Frank

[mikerwt]

ignition switch wiring

I know this an old thread but was hoping you might beable to answer a question. Just got new switch from villiers but mistified as it only switches betweenthe blue and green I thought it should put both to earth? can you offer any thoughts? mikerwt.(25DB)

[John Wakefield]

Yes it should just earth the ignition coils when in off position.

[mikerwt]

ignition lock

Afternoon John glad to see you are on the ball. the switch I have only switches between the green and blue and not to earth so should I just put one of the wires to earth?

[John Wakefield]

Afternoon John glad to see you are on the ball. the switch I have only switches between the green and blue and not to earth so should I just put one of the wires to earth?

Looks like its the wrong switch, good old VS selling not selling duff parts again surely
As I see it BOTH coils should be earthed. Unfortunately Greeves do not show the ignition switch on their diagram but I have found this FB one for the 2T. http://i64.servimg.com/u/f64/15/94/92/99/00110.jpg There are two terminals which are both earthed in OFF position.
Here are a couple of photos I have taken of the switch on a spare engine, You can clearly see the external contacts that connect to an earthing bar. Pics are of the switch in the OFF & ON positions.
I suspect the switch VS have supplied is a repro single pole car type ignition switch