Ignition Coil Voltage

350 Sport & Touring, 500 Sport & Touring
DALORIAN
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Ignition Coil Voltage

Post by DALORIAN » 12 Jun 2017, 06:21

I am new to the forum and to the Moto Morini 500cc 1979 or earlier possibly that I just accumulated . I do believe that it is the red pickups with the regular black transducers. It does have electric start. The problem is that it has no fire whatsoever. I have checked everything but not getting any voltage at the green wire at all. I was just wondering if someone could possibly tell me what the voltage should be either at the ignition coil or the green wire if it is suppose to have any resting battery voltage that it picks up through the voltage regulator ? Even a small amount ? Or nothing ? or any through the fuse box through the coil. I am thinking that it is a permanent magnet type ignition coil, am I right on this ? If so , is there any voltage that I could measure anywhere ? Even a pulse through to the transducer , while cranking ? The pickups do measure continuity and the green wire measures about 225 ohms to ground when disconnected from the transducer . Any hints would be greatly appreciated. Thanks in advance.

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Tintin
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Re: Ignition Coil Voltage

Post by Tintin » 12 Jun 2017, 09:33

Hi, the ignition coil is stand alone, you should be able to start even without a bettery in the system (bumpstarting the bike)
If you don't get any voltage at all I think your green wire is grounded, usually your ignition switch or kill switch grounds the green wire when off. Could it be that you did not connect your ignition switch correctly adn is the kill switch funcioning OK???
Image
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Tom
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Re: Ignition Coil Voltage

Post by Tom » 12 Jun 2017, 12:13

I agree with TinTin: check ignition switch, kill switch (if your bike has the Electric Starter motor), but also very important: all your earth connections and cable ends!

I think a healthy primary ignition coil measures in between 60/70 volts. Your 225 Ohm's is an indicator that your coil (green wire) is OK.

But first, back to basics (thanks to Soren):

https://www.youtube.com/watch?v=FWyYDVuvCp8&t=4s

Tom
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Re: Ignition Coil Voltage

Post by Tom » 12 Jun 2017, 12:21

Another hint: 500 black red dotted transducers and red pick up are weak. Most of the time one transducer or one magnet on the pick up is gone!

Luckily you can buy new trandsducers and/or pick up, for instance Marcus Heilig.

Make sure you buy the correct combination transducer and pick up.

DALORIAN
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Re: Ignition Coil Voltage

Post by DALORIAN » 13 Jun 2017, 03:23

I suspected that the wires may possibly be in the wrong config on the switch but have not way of identifying which color goes to the proper number on the switch. Would anyone possibly have the configuration of which color goes to which number ? I have the schematic but it doesn't really have an accurate picture of the back of the switch. Thanks again.

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Tintin
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Re: Ignition Coil Voltage

Post by Tintin » 13 Jun 2017, 08:47

you can check this by pulling the green wire from the kill switch from the terminal block, then all should work. I will check if I have a 500 switch somewhere, I think I have a wiring loom from a 500 project somewhere but can't remember if the switch was still on.
"Innamorato di vecchi motocicli Italiani"

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350-v-twin
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Re: Ignition Coil Voltage

Post by 350-v-twin » 13 Jun 2017, 12:16

The handlebar switch inside:

Image

It is in German, this is the translation in English:

Horn rt red
vi violette
Flash ws white

bl blue
Indicators or orange
gn green


High beam
sw black
Normal


off br brown
parking light ge yellow
on gr grey

DALORIAN
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Re: Ignition Coil Voltage

Post by DALORIAN » 14 Jun 2017, 02:44

Since I posted I did notice something else in the circuit . There is a terminal strip with a diode, separated from everything, the cathode goes to the switch on the green wire and the anode goes to the transducer. This diode appears to be separating the transducer from the switch. When the key is
inserted without turning, the terminal where the green wire goes or went to begin with is grounded. When the key is turned to first position it is still grounded, then when turned to second position the ground disappears from the ignition switch. I don't know if this diode is something added or if it came with the bike ???

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Tintin
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Re: Ignition Coil Voltage

Post by Tintin » 14 Jun 2017, 08:03

in which position can you pull the key from the ignition switch? If it is in the first position this is the "parking" position, then you can switch your rear light and pilot bulb in front on when you park the bike out in the badlands in the middle of night. Feature of all bikes of that era :wink:
I suppose you cannot pull the key in the second position, this is the position ment for driving
"Innamorato di vecchi motocicli Italiani"

Tom
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Re: Ignition Coil Voltage

Post by Tom » 14 Jun 2017, 10:39

I am not an expert, but if that happens it's suggesting that your ignition switch is working OK: turn key left - ground- ignition is turned off, turn to the middle position - ground- ignition is off, turn right, no ground on the switch, Voltage from coil can feed the transducers. Now, the diode on the green wire near the fuse box should be there, it's an extra security for too high (Amp?) Voltage to go back into the ignition circuit and destroy things there, so i am told. Older type Morini's don't have this diode on the green wire.

Again, i suggest to go back to basics with Soren his video's on youtube first.

DALORIAN
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Re: Ignition Coil Voltage

Post by DALORIAN » 18 Jun 2017, 03:03

I have a feeling that the switch is okay but the configuration of the wires to it may be wrong but cannot prove it until I get some kind of color to the corresponding number on the back of the switch . The switch has numbers for each terminal but the schematic has not numbers to match up , just a half way picture that does not match up to the back of the switch. There is a terminal in the middle and to the side but the picture of the switch on the schematic looks nothing like it .

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350-v-twin
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Re: Ignition Coil Voltage

Post by 350-v-twin » 18 Jun 2017, 10:12

Few remarks:

1) I hope you have not connected the transducers to 12V of the battery, as it destroys them. The transducers should only get their energy from the special coil of the alternator,
2) make sure the earth connections on the bike are allright. In the past I was in contact with a person who had the frame repainted. He forgot to scratch blank the spots for the earth wires. Without good earth connections, the bike won't start,
3) the genuine later (plastic) CEV handlebar switch on a Moto Morini for the lights, horn, turn signals etc. should have 2 white plastic connectors. If it has only got 1 connector it probably comes from a Moto Guzzi or similar.
The 2 connectors look like this:
Image
these 2 connectors can only be connected to the wiring harness in one way. Unless someone messed-up the wiring, this can't be wrong (you can't connect them upside down).

DALORIAN
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Joined: 12 Jun 2017, 06:08

Re: Ignition Coil Voltage

Post by DALORIAN » 21 Jun 2017, 02:09

I am checking the pick up coils and find that they are about 107K ohms to 111K ohms . I don't know if this is correct or not but seems a bit high. also I tried to take the pick up coils off from the camshaft by taking the locknut and the allan screws off but it's stuck and I did not want to damage it by forcing it. I don't know if it needs some kind of a puller or what ?

DALORIAN
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Joined: 12 Jun 2017, 06:08

Re: Ignition Coil Voltage

Post by DALORIAN » 21 Jun 2017, 03:27

Well, I have an update to post on this , I did finally get the pick up off from the camshaft . I checked it out and it measures about 600 ohms on diode check just one way only on both coils. I did not realize that there was a diode in this pick up. I don't know if it is good or not. Now the green wire from the ignition coil puts out about 30 volts AC when cranking . Again I don't know if this is sufficient or not but this is what it puts out when disconnected from the ignition box.

Tom
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Re: Ignition Coil Voltage

Post by Tom » 21 Jun 2017, 09:20

These are some nice figures, but what do they say? To be honest, in my opinion, if you want a reliable Morini, get rid of the red pick up and black transducers and upgrade to the later version (black pick up, grey boxes) or get one of the aftermarket transducers (see the video's on youtube i have shown you) with the Marcus Heilig pick up.

I have worked on quite some 500's and i always have seen problems with the original ignition of red/black type (and they all had a spark in the beginning!). Strangly enough never had any problems with the early ignition of the 350 which uses the same red pick up but different transducers.

Last but not least, the Ohm measure on your primary ignition coil is only an indication that the windings are ok. It doesn't say a lot about if it will work properly.
So, a rewind will make the output much more stronger which will improve the spark.

These are my two cents. Good luck!

Oh, and check the flywheel for magnetism, maybe somebody has dropped it trying to change the cambelt.

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