Misplaced Spark, different igntion setup

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Misplaced Spark, different igntion setup

Postby holeinthehead » 04 Sep 2017 21:12

Hi All,
My 350's PO did some wiring mods and I'm a little confused about how it's supposed to go. The bike ran when I got it, but didn't have a battery or key/ignition switch (at least not a key) - nor did it have any kill switch. I put a key switch in - 4 terminals; I doubled up the grey and brown accessory/light wires just to get it going. Green goes to alternator/stator and the red winds up at the battery both via the fuse panel. The blue (ground)isn't used, the switch grounds itself.
Now, with the key turned on, I get 12v to the lights (br and grey) and the green wires where they end up at the ignition pack, but after I got things squared away, now I have no spark. After some reading, I think I have a different setup and hopefully haven't fried it with the battery.

I didn't make any drastic changes, just cleaned it up and figured out what was what. I'm hoping I just grounded something that wasn't supposed to be (the missing kill switch) but I'm not having any luck. This pickup/transducer setup is a little foreign - every way I know how to test a points system doesn't work.

Questions:
What is this setup? Is the box a single transducer for 2 individual coils?
How can I test? I read 220 ohms at the coil from + to - but I don't have any resistance.
Is the 12v that gets connected to green at the keyswitch right?

Thanks in advance.

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Re: Misplaced Spark, different igntion setup

Postby Steve Brown » 04 Sep 2017 21:30

First thing, that ignition system is not the Morini original. It looks a little like the NLM system BUT! it isn't quite like the NLM system I have on mine. So possibly another persons work if not a earlier/later version of the NLM type.

The important points are;
1) You don't want 12 volts anywhere near the transducer/black boxes! The Standard and NLM system is self generating via the flywheel/stator.

2) If the components are good, then make sure your green wire is not earthed. That is how the standard system switches the ignition off.

3) All the stuff you know about points and coils is irrelevant here!

4) If you have given the transducers/black boxes 12 volts they will most likely be fried, as you said.

5) If you don't have a full understanding of the system and some very specialised kit you won't be able to test much of this other than by substition.

Sorry that's all a bit negative sounding and hope you get round the problem.
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Re: Misplaced Spark, different igntion setup

Postby 72degrees » 04 Sep 2017 22:16

That looks like an NLM "two cable group" module with separate coils. I'm running that on the hill climb bike. The road one has the earlier one cable group box.
The green wire from the stator should go to just the green connection on the one cable group. The yellow is for the electronic tacho. The ignition switch should short out the green to earth via a branch IYSWIM. There should definitely not be 12v to the green connection on the module! You may have fried the gubbins in that, but I'm not sure if it uses the same thyristor system as the OEM setup, so if you redo the connections correctly you might be OK. I've got an idiot sheet somewhere that NLM produce. Aha! Scan attached.




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Re: Misplaced Spark, different igntion setup

Postby holeinthehead » 05 Sep 2017 06:46

Thanks All,
I fear the worst, so just in case is NLM = North Leicester Moto?
I will rewire and give it a go, but I think I tried a version of that with no spark. With all that, it makes sense now that the green going to the ignition switch is meant to ground out to the blue to kill the engine.
If I need a new box, is NLM the way to go? I thought I saw something about old Vespa transducers working.
Sigh...
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Re: Misplaced Spark, different igntion setup

Postby 72degrees » 05 Sep 2017 07:04

Yes, North Leicester Motorcycles. They are still supplying that module. They sent me one about a month ago.

The Vespa units are replacements for the OEM transducers and have built in coils, so you would not need the two separate HT coils in the setup you currently have. I have no experience of using them but I think others have found they work, though there may be a question mark over the advance curve.

I find the NLM system used with a red type 2 pickup works very well. It also works with their own pickup but that requires very careful setting up and a higher kick start speed.

I'd try minimising the wiring first by just running a connection from the green wire straight to the module and eliminating the ignition switch.

Also, though 220 ohms sounds OK for the ignition winding resistance it's worth testing what A/C volts output you get on the green wire at kickstart speed to eliminate a rotor with poor magnetism. Though in you scenario when it was starting before it sounds like a wiring error or a fried module as a result of one :(

I'm so paranoid about the ignition on the 'racer' that I keep the OEM transducers still mounted on it (a 250 so under a side cover not the tank) and carry a 'known good' pickup to all events. I think I'm also going to start carrying a rotor puller and stator once I get a spare one I have rewound ;)
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Re: Misplaced Spark, different igntion setup

Postby 72degrees » 05 Sep 2017 07:08

By the way. The NLM instructions reference to "black from pick up" is for their own pickup. OEM will have red for both cylinders but the front cable should have a white tag to identify it. From your photo it looks as if you have an OEM pickup of some type.
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Re: Misplaced Spark, different igntion setup

Postby fastharry » 05 Sep 2017 10:56

What kind of voltage would you expect from the green wire if your testing the rotor /stator.
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Re: Misplaced Spark, different igntion setup

Postby 72degrees » 05 Sep 2017 11:22

fastharry wrote:What kind of voltage would you expect from the green wire if your testing the rotor /stator.


I hope to see a peak of up to 50v A/C and my rewound and re-magnetised setup on road bike does, but according to evguru 30 should be enough to give a decent spark. The racer is at least that, despite a winding resistance of significantly less than 300 but I can't remember what it is! I ought to test it all again now I *think* it is all OK, as a base mark for future reference.
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Re: Misplaced Spark, different igntion setup

Postby fastharry » 11 Sep 2017 20:35

Ok thanks, Is it possible to get 300 ohms, i am about to have a go at rewinding one,
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Re: Misplaced Spark, different igntion setup

Postby 72degrees » 11 Sep 2017 22:50

Possible using the right gauge wire, but not essential. I haven't tried it myself but there is a 'how to' out there on the internet.
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Re: Misplaced Spark, different igntion setup

Postby Ming » 12 Sep 2017 06:39

fastharry wrote:Ok thanks, Is it possible to get 300 ohms, i am about to have a go at rewinding one,

Have a look here, it's easy enough, if a bit boring.
http://www.motomoriniclub.nl/rewindignitioncoil.html
You might want to try a similar coil from a Vespa / Lambretta (available from India, like some of the alternative CDI units). They are a similar size, but are wound with a finer wire, so higher resistance. I don't know whether that means they would be overloaded by 2 transducers, but may be worth a try.
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Re: Misplaced Spark, different igntion setup

Postby dalorian » 09 Oct 2017 05:24

I did all of the tests that Evagru instructed on youtube . Lights lite on all tests and stayed lit . I have 50 volts AC holding voltage on green wire but still no spark. I am glad you posted here that 30 was enough . Now I can go somewhere else on mine.
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