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Ignition coil replacement R80/7

Posted: Fri Dec 02, 2016 2:53 am
by cuno
Hello Everybody,


I'm Cuno and i'm new on this forum. I'm from Belgium and I'm 21 years old and in my sparetime i'm building caferacers or restoring some motorcycles.

Currently i'm working on a BMW R80/7, to save some space, I would like to replace the pretty big ignition coils by just one smaller coil.As originally there are two coils of 6V in series, I would like to use just one 12V coil with a dual output ( as both cylinders fire at the same time this wouldn't give any problems i guess).

I was thinking of the dual output mini coil frome dyna (DC1-2):
http://dynoman.net/ignition/dynacoils.html
this one has a primary resistance of 3ohm and a secondary resistance of 11500ohm
I was wondering if this coil would do the job or should it have another resistancevalue?
are there people who have done this before?

Thanks in advance,

Cuno

Re: Ignition coil replacement R80/7

Posted: Fri Dec 02, 2016 8:36 am
by barryh
Dyna green coils are commonly used as replacements on points ignition airheads and they are highly regarded. 3 ohms is the correct primary resistance.

Re: Ignition coil replacement R80/7

Posted: Fri Dec 02, 2016 9:26 am
by Kurt in S.A.
The combined resistance of the two coil setup is around 10K ohms. So it would seem that this would work.

Curious...what will you be doing with the additional space?

Kurt in S.A.

Re: Ignition coil replacement R80/7

Posted: Fri Dec 02, 2016 11:03 am
by cuno
Hello guys,

thanks for your reply.

as I'm making a caferacer of this bike, I want it to look as clean as possibel, so the large box wich holds the coils has to dissapear. The new coil wil be mounted inside the engine (at the place where the air filter used to sit). And then there will be some power filters mounted directly to the carb's
I'm rebuidling the rear end to fit a ohlins monoshock.

cheers,

Cuno

Re: Ignition coil replacement R80/7

Posted: Fri Dec 02, 2016 3:38 pm
by Texer
I did exactly that (R75/5) a few months ago. So far so good.

Re: Ignition coil replacement R80/7

Posted: Fri Dec 02, 2016 10:28 pm
by Texer
Texer wrote:I did exactly that (R75/5) a few months ago. So far so good.
Meaning the green dyna coil.

Re: Ignition coil replacement R80/7

Posted: Sun Dec 04, 2016 4:08 pm
by cuno
Texer wrote:
Texer wrote:I did exactly that (R75/5) a few months ago. So far so good.
Meaning the green dyna coil.
Thanks!
it's nice to know that it works fine, I've ordered one yesterday.
I wont be firing up the bike in the near future because there's a lot of esthetic work to be done before i can actualy build up the bike again.
But i'll post the resultst here when I'm done.

Cheers,

Cuno