Wasted Spark ?

hooksey said:
Dunno but Migel will need a bigger one to straighten his top tube 🤣🤣
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😮‍💨😁🤦🏼‍♂️😝💩💩

Actually I am planning already something… but I will post it when is finished. And successful. I want to keep my right to presumption if innocence😅😅

I will just say: 5 tone jack. 2 pieces of chain.

This hammer is for left handed, I am right handed.

Miguel
 
The point is that its not the ignition box that's a wasted spark device. Whether or not it's a wasted spark system depends on how the pickups on the engine are configured. The ignition box just fires the coil(s) whenever the pickups tell it to.
 
control boxes for ignition systems are not quite as simple as that, they have an advance curve, some have switchable advance curves, some have programmable advance curves, some have rev limiters, some have programmable rev limiters, some have a setup led, some are self generating, some require a voltage source, some are wasted spark some are not. I thought I was asking if what I have fitted to my bike was wasted spark or not. Hey ho …..
 
Sounds very much like you have a wasted spark system,
To check look at the ignition trigger and see if it has a way to tell which phase it is in,
Secondly, do you have one or two coils? (2 singles or one double)
If two singles, are they controlled by the same signal wire?
Post pics and I am sure you may get better feedback.

Regards,
J
 
The DMC 2 I fitted to the Mirage came with two HT coils,one single lead for the mid cylinder,the other a double lead for the outers.
These were fitted where the Bosch CDI "black box "used to be.
The original Bosch CDI generator plate was retained with it`s two pick up coils so the double lead HT coil would supply sparks to the two outer cylinders simultaneously,regardless of what each individual cylinders` pistons and valves were up to.
Ripped out the original pressed steel tool tray behind the battery and rubber mounted a thin stainless steel plate vertically behind the battery to fix the DMC control unit to (don`t like things dangling loose),and fixed the silver matchbox rectifier to that as well.
It was then I discovered the DMC 2`s greatest flaw-once the unit is screwed in place you can`t get to the curve selector,the stupid thing is positioned at the rear of the unit and is now inaccessible.
I suppose you could experiment with the different settings before finally fixing it in place but in truth my seat of the pants dyno couldn`t tell any difference between the curves I tried so in the end I just chose one (eleven I think),fixed the thing in place and let it get on with it.
 
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Thanks, everything points to wasted spark. Certainly has double coil with LT side fed by single wire.
thanks again, richard
 
julian said:
Sounds very much like you have a wasted spark system,
To check look at the ignition trigger and see if it has a way to tell which phase it is in,
Secondly, do you have one or two coils? (2 singles or one double)
If two singles, are they controlled by the same signal wire?
Post pics and I am sure you may get better feedback.

Regards,
J
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Far easier than that, Julian.

ALL DMC systems, irrespective of twin or triple, run wasted sparks. "Sequential" systems can be had for 750s, on special order only.

How do I know this? I helped develop and manufacture the things back "in the day" and am still involved with road-testing the newest developments for Herr Witt.

piet
 
tribonnie said:
control boxes for ignition systems are not quite as simple as that, they have an advance curve, some have switchable advance curves, some have programmable advance curves, some have rev limiters, some have programmable rev limiters, some have a setup led, some are self generating, some require a voltage source, some are wasted spark some are not. I thought I was asking if what I have fitted to my bike was wasted spark or not. Hey ho …..
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No, no, no. They're not! That's the point I was trying to make with the left handed hammer gag. Geez, I feel like I'm getting concussion from bashing my head against a brick wall.

All of the other characteristics you list can be attributed to the ignition box or its software. But wasted spark has nothing whatsoever to do with the ignition box itself. Just as the hammer can be left or right handed depending what hand you hold it in, an ignition can be wasted spark or not depending which bike it's installed in.

So your original question made no sense. Nobody can tell from a photo of the box whether it's wasted spark. That's why Piet's immediate response was "No, it's a DMC II ignition system".

I'll try another metaphor that's closer to the subject: It's like posting a picture of a spark plug and asking if it's a wasted spark type plug. It has nothing to do with the bloody plug itself.

If you'd asked the same question with a photo of the bike, you'd have got a sensible answer. Although you didn't actually need a photo. Just identifying the bike would have been enough.

That's it. I'm done trying to explain it.
 
listen to Piet PERLEASE!

his one word reply should have been enough.

dead simple, if you have a double outlet coil, feeding the outer cylinders, then you have a wasted spark system, both leads/plugs from this coil spark at TDC (ish, advance curve dependant) but only one is going to FIRE! its mate is busy pumping shit out (like many repliers) the other coil does the same.
wasted spark it is, WHY DO YOU ASK?
CLEM
 
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rocketonarail said:
It was then I discovered the DMC 2`s greatest flaw-once the unit is screwed in place you can`t get to the curve selector,the stupid thing is positioned at the rear of the unit and is now inaccessible.
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Due to the design of the 2 internal circuit boards and the location of certain thyristor heatsinks, it simply isn't possible to position the switch on the other side. We've tried... just wouldn't work without complicating matters elsewhere.

piet
 
sfcpiet said:
Due to the design of the 2 internal circuit boards and the location of certain thyristor heatsinks, it simply isn't possible to position the switch on the other side. We've tried... just wouldn't work without complicating matters elsewhere.

piet
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Thanks that would explain it then,not really the end of the world but just wondered why it was like that.
As I said it`s the only downside I could think of,it works well,simplifies and removes a lot of the tired old wiring including the horrible multi connector under the nose of the seat.
Only other thing I had to do was find a newer replacement generator CDI plate as the originals pick up wiring was on it`s last legs.
Tony.
 
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