BMW R65 `84 ignition coil connection problem

[cerkas]

Hello,
I would like to ask how properly connect ignition coil for my BMW R65 `84, because currently it seems there is left a mess from the previous owner. 
Is this metal frame number 4 is necessary at all?

I attach photos of right and left side of the motorcycle with marked parts from 1 to 5.

Maybe somebody will be able to explain it to me. 

[georgesgiralt]

Hi !
It looks like you have a mix between post 1981 and pre 1981 ignition system.
The coils are from the pre the ignition module are from the post. You should check the bean can to see it it uses points or Hall sensor .
If you have a bean can with points maybe the metal plate which seems to hold a capacitor is there because the capacitor on the bean can is difficult to reach ...
I'm a bit puzzled.

[dogshome]

I'd go so far as calling that a non-working temporary mess!

This may help:
https://bmwmotorcycletech.info/Euro-R45-R65-R80ST.pdf
https://bmwmotorcycletech.info/R65Schematic.htm

[dogshome]

Ive re-wired my '83 RS65 and know almost every inch of it. All of that additional stuff wants taking off and binning. You will require a single new coil unit with two HT lead connections, don't try to work with the dual coils as a) there is nowhere to mount them b) they may be the wrong voltage / current and c) It makes understanding more complicated - get it back to standard wiring. What the condenser, dioide and whatever else is doing on that bit of tin is anyones guess.

OK, you have a post 81 bike as I can see an electronic ignition module. It should have a hall effect switch in the 'bean can' and not contact points. Check if you have an electronic bean can or a points variety, some knuckle-draggers (sorry, senior bikers) prefer points and may have fitted a set from an earlier bike. Like a bronze sword, much more trustworthy than a steel one. Copper swords? ah those were the days..... 

There are possibly other failed components in the system. Was the mess done to show you a running engine, or have you never seen it run?


The bits you are interested-in on the diagram are these few on the attachment.   

[dogshome]

It is very simple, nothing like a modern bike. The engine rotates, the sensor sees it, the electronic ignition acts as a relay and switches the coil. You get a spark every revolution on both cylinders, so half the sparks are 'wasted'. Its done this way as it's incredibly simple.

The older bikes use points instead of a sensor, and electronic relay. There is only one contact set, two sets are not needed due to the wasted sparks.   

Post back how you get on, plenty of help on this forum for this sort of thing :-)

[cerkas]

Thank you for the replies. I checked the wiring schemes you shared with me, and it seems that ignition systems of pre and post 1981 are mixed. I will check electronic bean can and will let you know what will find there. I bought this r65 last winter and it was turning on, but after the winter when I finished repainting it, I tried to turn on and it did not work. There is no even a trigger in the sparks.

[cerkas]

Hi,
I checked and it seems that there is bean can in my R65.

I bought a double spark ignition coil and I can see that there is a place dedicated to install it.

Now can someone explain me how coil should be connected to plug connection to ignition? 

[georgesgiralt]

Hello
The double output coil you show in your las picture is the dreaded grey "crak-o-matic" coil whom grey plastic break causing the coil wire to fail in unexpected place and time.
If you want to install a double output coil I suggest you buy a newer double output coil. There is also a plastic sheet meant to protect the coil from the water projected by the front wheel and the wind. I suggest you find one and install it.
Lastly, there is a grey braided wire shown in your first picture. What it is used for ? Because it is not part of the original wiring.

[dogshome]

Hiya, the 3 wire bundle coming out of the (electronic / hall effect) bean tin goes up throught the top of the motor and should plug directly into the ignition module that lives under the tank on the RHS. Another 3 wires come out of that and are ground (brown), 12V (black) and coil (Green&Black). See the diagram above. It is almost as simple as points ignition - even if it looks like spaghetti right now.

Something has probably failed, which is why the mess from the previous owner. The ignition coil likely. You can test the new one for impedance and see if it has any visible cracks or spark marks, but the grey ones do have a reputation for failing. It works just like any other standard coil though, except there are 2 HT connections, one to each cylinder (doesn't matter which). One LV terminal goes to Green&Black and the other LV terminal to brown. It might work well enough to try, but will be infuriating if it's already faulty.

Keep going, you'll get there, where in the world are you?

[cerkas]

Hello
The double output coil you show in your las picture is the dreaded grey "crak-o-matic" coil whom grey plastic break causing the coil wire to fail in unexpected place and time.
If you want to install a double output coil I suggest you buy a newer double output coil. There is also a plastic sheet meant to protect the coil from the water projected by the front wheel and the wind. I suggest you find one and install it.
Lastly, there is a grey braided wire shown in your first picture. What it is used for ? Because it is not part of the original wiring.

Hello georgesgiralt,
I heard that this old model of coil is faulty, but I found this one for 50 EUR and grabed it, later on I will get a newer model. Ok, I will try to find a plastic sheet for the protection. I have no idead for what is your mentioned grey braided wire, probably this is left from the previous owner mess.

[cerkas]

Hiya, the 3 wire bundle coming out of the (electronic / hall effect) bean tin goes up throught the top of the motor and should plug directly into the ignition module that lives under the tank on the RHS. Another 3 wires come out of that and are ground (brown), 12V (black) and coil (Green&Black). See the diagram above. It is almost as simple as points ignition - even if it looks like spaghetti right now.

Something has probably failed, which is why the mess from the previous owner. The ignition coil likely. You can test the new one for impedance and see if it has any visible cracks or spark marks, but the grey ones do have a reputation for failing. It works just like any other standard coil though, except there are 2 HT connections, one to each cylinder (doesn't matter which). One LV terminal goes to Green&Black and the other LV terminal to brown. It might work well enough to try, but will be infuriating if it's already faulty.

Keep going, you'll get there, where in the world are you?

Hi dogshome,
thank you for the guidance of connecting coil to ignition module and hall effect. I will try to work on it, when I will get wires and spark cables. Do you have any e-shop reference for the wires for r65? I found this French website https://www.bike-parts-bmw.com/, but I have not bought anything from them yet.

I am in Lithuania 

[cerkas]

Hello,
can someone explain how cables should be connected to the coil? I marked cables in red and coil connectors in green. 

[Barry]

I don't recognise the coil but in general for dual output coils the polarity doesn't matter. 

For most dual output coils, one plug will spark centre electrode to earth strap and the other plug will spark earth strap to centre electrode so changing the polarity of the coils primary connections makes no practical difference.

[cerkas]

Hello,
I am coming back with question related to cables connection to the coil.
I connected cables as showed on the picture, but motorcycle does not start.
The starter operates. Does anyone can explain whether cables are connected correct?
Also, what could be the problem?

p.s. The coil in the picture is Bosch 0 221 500 200.