Electronic Ignition Conversion

Post your post 1970 technical queries here

Moderator: Moderators

User avatar
Jon S
Club Member 13
Posts: 133
Joined: Sun Sep 03, 2017 10:27 am
Country of Residence: UK
Location: West Cumbria

Electronic Ignition Conversion

Postby Jon S » Wed Jun 13, 2018 8:50 pm

Hi to all you Airhead Experts.
I'm considering converting the Bean Can points ignition on Brunhilde' my 79 reg R100RT to this new fangled electronic stuff.

Looking at Motor-Works site I see there are two system Boyer Brandsen and Siemens, the question is which. The Boyer is £100 cheaper than the Siemens unit so that may very well sway my choice. :???:

Just to add to the confusion there are two Boyer units, one uses the original coils while the other has a dual outlet coil, new plug leads and plug caps. :???:
Regarding Boyer, I have read about problems with these but to be fair, it was about installing electronic ignitions to magneto equipped classic Brit bikes.

I'm not a total numpty and have fitted a EI system in place of the magneto on my other 'love' a 62 reg Norton Slimline 99 Dominator without much heartbreak so I reckon that I'll manage to do the same with Brunhile'. It's a pity that the company that made the system I installed on my Dommi only do EI conversions for magnetos fitted to Brit bikes otherwise I would go down the same route.

Also I assume that Brunhilde's coils are original (they look old enough) so they've done circa 60k miles and though they haven't failed yet I guess a new EI system may push them over the edge. :???:

Now then you chaps who have far more experience than me what's your opinion and /or recommendation, Boyer or Siemens?

All/any advise will be greatly appreciated

JonS
"Never push a full commode" :grin:

barryh
Forum User
Posts: 918
Joined: Wed Jan 14, 2009 10:13 pm
Location: Cheshire, England

Re: Electronic Ignition Conversion

Postby barryh » Wed Jun 13, 2018 9:22 pm


Regarding Boyer, I have read about problems with these but to be fair, it was about installing electronic ignitions to magneto equipped classic Brit bikes.
While I have no direct experience with Boyer ignitions, on the basis of various airhead forums, there does seem to be more grief about Boyer ignitions than any other type. I suspect that's only because they are more sensitive to correct installation but people do still have problems with them. I'm sure many others will have run a Boyer system for years with no problems at all.

If you fit an electronic ignition that retains the original coils then there will be no improvement in spark energy other than perhaps at idle and low revs due to cleaner switching. While there are some other benefits, as far as spark energy is concerned electronic ignition is just transistor switch that replaces the points. To get a better spark you need a better coil which usually means lower primary resistance.

Points in a bean can is not a bad ignition system. Have you considered a points booster and a new dual output coil.

User avatar
Rob Frankhamr
Forum User
Posts: 2109
Joined: Mon Jul 25, 2005 6:33 pm
Country of Residence: Scotland
Location: Kinloch Rannoch, Perthshire

Re: Electronic Ignition Conversion

Postby Rob Frankhamr » Wed Jun 13, 2018 10:25 pm


If you fit an electronic ignition that retains the original coils then there will be no improvement in spark energy other than perhaps at idle and low revs due to cleaner switching. While there are some other benefits, as far as spark energy is concerned electronic ignition is just transistor switch that replaces the points. To get a better spark you need a better coil which usually means lower primary resistance.
A properly designed electronic system can give better control of dwell and eliminate points bounce which gives significant benefits in terms of energy at high revs in addition to the gains from the 'cleaner' switching waveform throughout the rev range.

Rob
Robin Frankham
ImageImageImage

Frankhams retirement home for elderly Boxers.

Mike D
Forum User
Posts: 1548
Joined: Thu Oct 18, 2007 3:12 pm
Country of Residence: UK
Location: Near Daventry, UK

Re: Electronic Ignition Conversion

Postby Mike D » Thu Jun 14, 2018 12:04 am

There is also a third option of using a crankshaft based system from Euromotoelectrics, which eliminates any issues with the camshaft runout:


http://www.euromotoelectrics.com/v/vspf ... ation1.pdf

Mike

varley55
Forum User
Posts: 12
Joined: Mon Mar 12, 2018 11:02 am
Country of Residence: France

Re: Electronic Ignition Conversion

Postby varley55 » Thu Jun 14, 2018 8:29 am

I fitted a Boyer Brandsen ignition to my 1979 R100RT after having it twin plugged. That was about 12 years ago and I have had no problems. It copes well with two twin coils. I would recommend it.

warmshed
Forum User
Posts: 37
Joined: Sun Nov 13, 2016 7:28 pm
Country of Residence: England

Re: Electronic Ignition Conversion

Postby warmshed » Thu Jun 14, 2018 8:48 am

The siemens one is marketed as red centre in Australia and has very good reviews. It has the electronic advance/retard so does away with the potential wear on the springs and bobweights. It is extremely easy to change out the hall effect trigger by the roadside, so making any future maintenance easy.
https://www.facebook.com/Boxerworks/vid ... 086292918/

warmshed
Forum User
Posts: 37
Joined: Sun Nov 13, 2016 7:28 pm
Country of Residence: England

Re: Electronic Ignition Conversion

Postby warmshed » Thu Jun 14, 2018 8:51 am

Last edited by warmshed on Thu Jun 14, 2018 9:09 am, edited 1 time in total.

Roy Gavin
Forum User
Posts: 136
Joined: Sun Jan 21, 2018 9:29 am
Country of Residence: Australia

Re: Electronic Ignition Conversion

Postby Roy Gavin » Thu Jun 14, 2018 8:52 am

I have had the original Boyer and a Dyna coil on my R75/7 for almost 20 years and it has been fit and
forget.
I also have the later micro power system on my twin plug 1000 cc hi- comp R80 G/S for the past 200,000 km and it has been similarly trouble free. And a big improvement on what was there!
The micro power comes with a coil and plug leads and caps, and I think I think a better curve and more robust circuitry than the early system - the curve on my G/S is excellent, and it pulls strongly from just over 2000 revs.
I have powered them direct from the battery with a relay activated by the normal coil feed - most ignitions like full volts, and of course the correct coils, leads, caps, plugs and plug gap-------.
One problem with other systems mounted on the face of the alternator is that the wires from the winding's to the slip rings are soldered to the slip rings at the front, and the new ignition trigger is not able to sit flat unless the blobs of solder are cut back, and if you do the alternator does not work - DAHIK!

barryh
Forum User
Posts: 918
Joined: Wed Jan 14, 2009 10:13 pm
Location: Cheshire, England

Re: Electronic Ignition Conversion

Postby barryh » Thu Jun 14, 2018 11:20 am

I did say that electronic ignition provides some benefits even if the original coils are retained but I'd consider it a poor return on investment.

Spark energy is proportional to I/2 the primary inductance times the primary current squared so the increased primary current provided by lower resistance coils will provide a big increase in spark energy. The benefits of cleaner switching are relatively minor by comparison. That's why when BMW introduced electronic ignition in 81 they lowered the coil resistance and years later lowered it again. Every other modern application of automotive electronic ignition has low resistance coils. The additional benefit of lower resistance coils is that they will also be lower inductance and therefore saturate faster maintaining spark energy at high revs.

Bottom line for me is I wouldn't spend big money on electronic ignition unless it was matched with better coils and also took control of dwell and ignition advance.

warmshed
Forum User
Posts: 37
Joined: Sun Nov 13, 2016 7:28 pm
Country of Residence: England

Re: Electronic Ignition Conversion

Postby warmshed » Thu Jun 14, 2018 2:41 pm

Its more a question of getting rid of the potentially troublesome mechanical contact breakers which i believe is reason enough to go for electronic ignition as have all the modern cars and bikes.

User avatar
Jon S
Club Member 13
Posts: 133
Joined: Sun Sep 03, 2017 10:27 am
Country of Residence: UK
Location: West Cumbria

Re: Electronic Ignition Conversion

Postby Jon S » Fri Jun 15, 2018 9:14 pm

Many thanks to all who have replied to my question. You have clarified the mud somewhat. For now I'll be sticking with the old school points and see how things go, up to press Brunhilde' is running fine so there is no immediate need to go for the new fangled electronicary.
Help much appreciated.
JonS
"Never push a full commode" :grin:


Return to “Airhead Q&A's”

Who is online

Users browsing this forum: Majestic-12 [Bot] and 2 guests