Older DMC

drikko

Hero member
Location
Orstralia
My DMC was installed in '94 and doesn't look at all like the DMC2, it has dip switches rather than a rotary one for maps and setup. Does anyone have the installation/user manual for these? There's no writing on it I can see, they were engineers not marketeers I suspect :)
 
Drikko,

Can you recognise the switch settings, ie where ON/OFF are?  Often faded and the switches damaged.  What model is it for?  Does it have a blue anodised housing or is it plain aluminium?

The DMC I has 6 curves to choose from, set by different combinations of switch settings.  I'll have to dig deep to find a manual for it and scan the curves.

piet
 
G'day Drikko

It's a DMC 1 (blue box), same as on my Jota. I have a pdf manual for it, but it's 870KB, and the maximum size I can attach here is 600KB. I'll email it to you.

Purely from my own experience with it, I don't think the DMC 1 is a very good product. If yours is running OK then hopefully you'll not have a problem. Mine has needed a bit of help to keep it going, and it still has occasional hiccups. I'm seriously considerng replacing it with an Ignitech, even though I have a spare new DMC 2 (brown box) sitting on the shelf. My problems with the DMC 1 have undermined my confidence in Witt DMC ignitions.

Cheers,
Cam
 
Piet and I posted at nearly the same time (I'm a slow typist).

I didn't know Witt made a plain aluminium box version as well. I thought there were only blue and brown boxes.

Cheers,
Cam

 
Thanks Cam, gottit. Yes it's a blue anodised box. The switches are on the inside so I'll have to remove it to see what it's set to. I notice the advance curve settings have the option of increased advance. Is there any benefit to that? I feel that the power down low is less than what I am happy with.
 
I don't remember what curve I'm running, but my Jota would be different to your RGS anyway.

In general, increasing your advance is not going to give more power (unless it was too retarded beforehand) and it could cause problems. You need better advice than I can give you. Piet knows more about the DMC boxes than anyone else here. The important thing is to make sure your datum is correct. By that I mean the pickups must be in the right position to tell the ignition system where TDC is.

I chose the advance curve on my Jota by doing a few runs on a dyno while switching between curves, then picking the one that gave the best spread of power.

Cheers,
Cam
 
As previously advised in similar posts on this topic, those bastards at the ILOC have the DMC info available to allcomers here  :P
http://www.iloc.co.uk/index.php?option=com_wrapper&view=wrapper&Itemid=90
I seem to recall one of the documents may even be from Cam!

There's the full DMC1 manual with explanations and curves.  Here's a summary from a previous post on the subject

Curve 1 [32deg] - as set by the manufacturer
Curve 2 [26 deg] - use with very poor petrol or pre-ignition with poor petrol
Curve 3 [29 deg] - use with poor petrol or pre-ignition
Curve 4 [32 deg] - revs limited to 6500 for 'running in'
Curve 5 [34 deg] - as set by manufacturer, but with a different max advance
Curve 6 [34 deg] - for motors with lower performance at low revs (e.g. 3-in-1 exhaust)
Curve 7 [36 deg] - as set by manufacturer, but with a different max advance
Curve 8 [36 deg] - for motors with lower performance at low revs (e.g. 3-in-1 exhaust)

Curves 1-8 are set by the first 3 DIP switches. The fourth DIP switch puts the unit in test mode
 
Oh dear, Brad. I'm afraid you'll have to become a CLOT (Club Laverda of Tasmania) member to access that document.

Membership fee is a pint of ale, but you have to deliver it to my place without spilling (or drinking) any.

Cheers,
Cam
 
Fantastic cheap resource Brad!
shocking how the years go by...the  Slaters day seems like yesterday, as does the 06 Cor Dees museum opening..
Nick7
 
Cam,

The very first (about 100 units) DMCs were plain aluminium.  Uwe soon decided to supply the boxes with a more durable finish, the plain boxes didn't hold up well to the nasty environment found on a motorcycle (oil and fuel, battery acid, moisture, road salt, etc, etc).

Although the DMC was originally devised to replace the crude Laverda electronics, there was soon demand from all over the place.  Very quickly, Uwe built them for all manner of points-equipped bikes, ranging from Moto Guzzi to BMW, Yamaha XS650, Honda 4s, Benelli 4s and 6s, H-D V-twins and a coiuple of others I've since forgotten.  They were a mainstay within the Guzzi fraternity for quite a while...

piet
 
I have the DMC1 blue box fitted on my sfc1000, around 1987, and it works perfectly.
I have a friend who installed his DMC2 on a similar bike1? year ago, and after 1 year, I had to help him replace a defect optical pickup/wire/connector. Works fine now, but he drives with a spare pickup/wire/plug, for good measure.

Cheers,
Jacques.
 
Have a DMC1 in the Jota since 1993 - never had an ignition related issue ever since
Have a DMC2 in the 1000 SFC since 2000 - never had an ignition related issue ever since
Have had a DMC2 in the 750SF - very smooth running nice little bike it was, started on first hit of the button always.

Have two more 1000 SFC with Witt ignitions, one has one of the very first silver models. This bike is currently under restoration, can't tell if the ignition works, as the bike is not yet finished.

HTH
 
Running IgniTech in the race bike, as are all members of OzLaverda Racing. Simple, efficient and easy program.
Not surprising we're all on one in the team, as Steve Battison's the man for 'em locally.
Drop him a line Cam for the inside scoop... www.breganzane.com
Ciao
Ian
 
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