Author Topic: Sachse Ignition  (Read 1932 times)

Offline Gravelroad

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Re: Sachse Ignition
« Reply #30 on: April 21, 2017, 11:43 »
Strange indeed. When you connected the battery the wrong way round, the windings of the alternator coils have been powered up via the R/R unit, converting them into powerful electromagnets with heaps of Amps going through them. That has been the sparking you have observed while connecting the battery with reverse polarity.

The massive magnetic spike created by the alternator coils could have, at least in theory, affected the magnetic rotor of the ignition trigger, if we are talking about mk1 triples, but I do not see this happen on an mk2 with the alternator sitting far away from the ignition rotor.

Once you had finally released the battery cable, the collapsing magnetic field of the alternator coils caused a massive voltage spike towards the R/R. In worst case this voltage spike passed the R/R just being converted to a positive voltage spike, now running towards the negative of a battery, which is disconnected at its positive, so no relief found here. Hard to tell where he energy of that voltage spike has been dissipated finally, could be anything upwards the + connection of the R/R.





Offline Willz900

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Re: Sachse Ignition
« Reply #31 on: April 21, 2017, 17:50 »
I am at a loss to know what to do, this has been going on for too long and I am no nearer finding out what the problem is.

I have two boxes and I get the same results with both of them, I have a new trigger board as I found that the earth wire close to the box had got damaged, it broke off just inside the sleeve.

I have tested the Coils and get readings close to the Dyna specs, the double coil has no polarity so wires can be on either way and the single has a red dot on the positive, so not wired incorrectly.

It seems to be related to when the L.E.D's come on and is sending a false signal to the coils, ?


Offline Rob

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Re: Sachse Ignition
« Reply #32 on: April 21, 2017, 18:52 »
Sounds like you've disturbed quite a bit of wiring to remove box; trigger board; alternator and anything else along the way.  I'm not familiar with Sasche systems but it's the easiest thing in the world to disturb a connection (like your damaged earth wire) or make a mistake when reconnecting.  Can only suggest you carefully check each and every connection in turn.  You'll likely kick yourself when you find it.  On RGS wiring it's easy to swap one of the smaller battery connections for example...

Offline Grant

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Re: Sachse Ignition
« Reply #33 on: April 21, 2017, 18:59 »
Can you check continuity of each wire leading from the triggers/alternator area to the r/r and black box?
Maybe something melted and shorted? Just a long shot.
You have checked all the obvious suspects so time to think laterally.
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Offline redax5

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Re: Sachse Ignition
« Reply #34 on: April 21, 2017, 21:25 »
I have two boxes and I get the same results with both of them, I have a new trigger board as I found that the earth wire close to the box had got damaged, it broke off just inside the sleeve.

common problem with the Sachse set up, brown wire is terminated to the outer sheath of the wire bundle cable and seems to be quite fragile

I have tested the Coils and get readings close to the Dyna specs, the double coil has no polarity so wires can be on either way and the single has a red dot on the positive, so not wired incorrectly.

that is actually not correct, both coils have the same pole as positive, compare where the single coil positive pole is and the dual is exactly the same, it is just missing its red dot

It seems to be related to when the L.E.D's come on and is sending a false signal to the coils, ?

so you said a couple of posts ago that you have the magnetic trigger set up so we can cross off bright lights effecting the optical triggers

way the Sachse system works which is exactly the same as the systems that we make ourselves work, the hall effect trigger is a switch and needs to be turned off and on which is what the magnets in the rotor do
as you rotate the engine in the correct direction of rotation, as the South pole magnet passes the trigger it turns the trigger on, that is when the LED light will come on next to that particular trigger. South pole magnet is marked by a "S" stamping on the face of the rotor

when the "N" being North pole magnet passes the trigger it switches the trigger off and the LED light will also go off
LED lights have nothing to do with what is happening apart from showing you that the triggers are off or on at any particular point of rotation

I will send you an email and get you to send me some photos of your set up to see if I can see what the issue is, doubt I will see anything but you never know
this is a very odd problem as you have said you have tried 2 different boards and 2 different boxes with the same result
most odd

You didn't remove the magnetic rotor and install it back to front did you ?
not even certain if the system would work if it was on back to front




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Offline chrisk

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Re: Sachse Ignition
« Reply #35 on: April 21, 2017, 22:09 »
I know nothing about the Sache black box, but the symptoms sound exactly as those on my Ignitech when it magically changed from the "customised" setting to some other bum fuck setting. Ran on one and farted and backfired like crazy with poor spark.

 I wonder if this could have happened during to reverse polarity mistake.
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Offline Shajota

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Re: Sachse Ignition
« Reply #36 on: April 21, 2017, 23:35 »
I know nothing but keep thinking about your comment earlier in the thread :-
"The bike turns over, but back fires all over the place."

That is exactly what it will do when triggers timed arse about which i am sure you know.
I also know Keith had already said to reverse the Lt wires to coils (easiest way to just swap em at the box) and you confirmed you had done this.
Did this change the way the bike tried to fire at all?

Just thought I'd throw this out there again........................ 
« Last Edit: April 22, 2017, 00:11 by Shajota »
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Offline Dellortoman

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Re: Sachse Ignition
« Reply #37 on: April 22, 2017, 00:13 »
I have a Beemer booked in next week for installation a Sachse ignition system (among other things). After reading this thread I'm beginning to dread the prospect.

In regard to a weak spark happening when the LED comes on, I don't think that's significant. All that's happening is the coil being energised in preparation for the actual sparking event (which happens when the coil switches off). During the coil energising phase there will be some voltage induced in the secondary side of the coil as primary voltage ramps up, which may produce a weak spark.  But a weak spark during the coil energising phase would be at around 100 deg or more BTDC and way too advanced to affect combustion.

If you're getting a healthy spark when the LED goes out, it would seem that your ignition system is working OK. You're getting backfire so fuel is apparently getting into the cylinders. Even if the carbs are way out of tune, the engine should still kick over and at least try to start. So pretty much the only thing left that could be wrong is ignition timing. If nothing has changed mechanically and the LED is going off somewhere near TDC, then the plugs must be firing on the wrong stroke. As others have said - swap the primary leads between the 2 coils.
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Offline Grant

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Re: Sachse Ignition
« Reply #38 on: April 22, 2017, 02:08 »
What voltage is at the battery as you crank the engine over?
I think the Sachse needs a certain voltage before it will fire.
Think it's 9V or thereabouts.
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Online AndyW

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Re: Sachse Ignition
« Reply #39 on: April 22, 2017, 03:21 »
If it all worked fine before he accidentally reversed the battery polarity then I'd say something is terminally fried...


Had this problem on my T160 once: fried the main (irreplaceable Motorola) transistor in the ignition box: went back to points...


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Offline Davo

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Re: Sachse Ignition
« Reply #40 on: April 22, 2017, 04:50 »
I have a Beemer booked in next week for installation a Sachse ignition system (among other things). After reading this thread I'm beginning to dread the prospect.


If it slots into a Beemer as easy as it did into my Le Mans you will have no problems to face at all. Even with my fear of electrickery it went as easy as.
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Offline Willz900

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Re: Sachse Ignition
« Reply #41 on: April 22, 2017, 12:33 »
Thanks Guys for all your input.

I am going to go over it all again today and see if I can find the problem.

I will get back to you and let you know how I get on with it.  ::)

                     

Offline Willz900

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Re: Sachse Ignition
« Reply #42 on: April 23, 2017, 12:36 »
I would like to say that I found the problem and fixed it, but no quite the case.  ::)

After taking off a reconnecting just about every connection I could find and putting them back in the same place, I have got the bike running again.  ;D

I don't know whether it was a loose connection or what but am just pleased to have it working again.

Thanks to everyone that took the time to reply.

                                          Cheers Will.




Offline Grant

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Re: Sachse Ignition
« Reply #43 on: April 23, 2017, 12:47 »
Glad you got it sorted.
Sometimes happens that way.
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Offline IAG

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Re: Sachse Ignition
« Reply #44 on: April 23, 2017, 16:44 »
 (Lavflag) About f-ing time!! (Lavinoflag)
Now, be honest, was it something simple you overlooked or really just disconnecting/reconnecting? Either way, happy to hear you're motoring again!
« Last Edit: April 23, 2017, 16:46 by IAG »
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