Electronic ignition

[deltarider]

Doesnt Hondaman on sohc.net do a electronic ignition for the 500/550 that incorporates the original points?

Yes and so does mine. Let's call his and mine a transistor ignition module to destinguish it from a full electronic unit. An advantage over the fancy expensive stuff is that, if anything goes wrong, the old situation can be restored within minutes. Mine has worked reliably for over 60.000kms with the same contactbreakers. I also like where my module is located, in a box attached to the battery (see pic) and not in a hot (condense) and vibrating place. If you make your own, make sure to use supple wire. My wires got hard and one came loose (after 15 years) when I removed the battery for winter storage. BTW, I advice first to have your project running with the oldstyle ignition before you throw money at it and then, when you're satisfied with the bike, you can consider going electronic which has some advantages like a better idle and somewhat more response in the high rpms. But do not expect even one HP more.

[AshimotoK0]

Doesnt Hondaman on sohc.net do a electronic ignition for the 500/550 that incorporates the original points?

Yes and so does mine. Let's call his and mine a transistor ignition module to destinguish it from a full electronic unit. An advantage over the fancy expensive stuff is that, if anything goes wrong, the old situation can be restored within minutes. Mine has worked reliably for over 60.000kms with the same contactbreakers. I also like where my module is located, in a box attached to the battery (see pic) and not in a hot (condense) and vibrating place. If you make your own, make sure to use supple wire. My wires got hard and one came loose (after 15 years) when I removed the battery for winter storage. BTW, I advice first to have your project running with the oldstyle ignition before you throw money at it and then, when you're satisfied with the bike, you can consider going electronic which has some advantages like a better idle and somewhat more response in the high rpms. But do not expect even one HP more.

I  too made designed my own but back in 1980. It was an 400v inverter CDI type as used on early Kwak triples but I still used the points as it was then literally a 5 minute swap over to standard if necessary (not that I ever needed to)  . Contrary to all of what you hear I never had to  re-time it or adjust / change  the points in 20k miles, all I did was lubricate the felt on the points plate regularly. I just passed a few milliamps through the points to 'electrically' clean the contacts. Redesigning it with modern parts (Capacitor was originally from a Pye Valve Colour TV, today I would probably use one from a microwave, although a little bulky.) but its a project that always seems to be 'on the back burner'  ) . This was on my 1st 400/4 and lived where the tool tray sits, it was still on it when I sold it. It retained the standard coils and you could get a whopping great spark from it.

[ginger_jim]

I guess electronic ignition units are only as good as the loom/charging system.  Cant see the problem with using the existing advance and retard unit as long as it is in good condition, particularly the springs.  I fitted a DS unit and haven't had any issues; I felt it was re-assuring to eliminate timing issues when setting the bike up.

[deltarider]

Contrary to all of what you hear I never had to  re-time it or adjust / change  the points in 20k miles, all I did was lubricate the felt on the points plate regularly.

+1. I remember that even with the old stock(!) ignition set up I returned from a 10.000km journey (France, Italy, Greece) and still did not need to adjust anything.

[totty]

Depends on your starting point, with genuine points, plate, coils etc. I'd try it first. If low quality after market bits are fitted I'd just go electronic as there isn't much price difference to a full set of original parts.
My 550 had a flat spot that I couldn't shift without replacing the advancer so I went Boyer.

[masonmart]

I'm probably going to buy Boyer or should I say Micro-Digital, these are recently priced and don't use the existing advance unit.

They need to use Micro Digital coils if the impedance of the existing coils isn't OK. Can anybody confirm if the existing CB500 K1 coils are OK in this respect

[Laverda Dave]

I fitted a Boyer to my 400/4 in 1992, its still in there going strong and I have never had to do anything to it once it was set. Ill be fitting another one to my project 400/4 no question.

[gtmdriver]

As far as I know, and I'm open to correction, the same unit fits all the early inline 4's. I'm using the Boyer unit on my CB350F.

Interestingly the Boyer system fires all 4 plugs together.

You also need to make sure the ignition coils have a primary resistance of at least 4 ohms.

[masonmart]

As far as I know, and I'm open to correction, the same unit fits all the early inline 4's. I'm using the Boyer unit on my CB350F.

Interestingly the Boyer system fires all 4 plugs together.

You also need to make sure the ignition coils have a primary resistance of at least 4 ohms.

The spec sheet shows a lowest primary resistance of >5 ohms

[royhall]

They will physically fit all the 4's but the advance curve is not the same on them all. I have one on my 350F that was made for the 400/4 that has a different advance. I was told it would move the full advance a further 1000rpm up the scale, but it still works really well. May not be too important.

[deltarider]

The spec sheet shows a lowest primary resistance of >5 ohms

Strange, are you sure?

[masonmart]

The spec sheet shows a lowest primary resistance of >5 ohms

Strange, are you sure?

Just from the manual that I have but I'll check. I measured my coils today and the primary resistance is <5 ohms. I'll buy the Micro Digital coils just in case. £100 is worth it insurance wise.

[deltarider]

Why the hurry. I'd rather expect B&B ment < 5 Ω because for example OEM Honda coils measure 4,7 Ω.

[gtmdriver]

This is a copy of the original instructions.



and this is the reply I got after enquiring about suitability for the 350/4

"Hi. Could you tell me whether the KIT00089 designed for the Honda 400/4 will also fit the very similar CB350F 350/4 which was its contemporary everywhere but the UK?

Hi, If it fires the same (has the same degrees for firing) and is also a single cam, then yes it should be fine. Regards Stuart


As standard it has two contact breakers set 180o apart with a single cam running at crankshaft speed. It uses the wasted spark system to fire two cylinders together.
I guess the only unknown is whether the ignition advance curve built into your system will also suit the 350.

I have found these figures in a genuine Honda service manual.

Honda CB350F centrifugal ignition advance
Start of ignition advance 1400 – 1600 rpm
Full advance reached 2300 – 2500 rpm
Advance angle 23.5o – 26.5o

Are these anything like the advance curve built into the KIT00089 electronic replacement?

Hi John, It sounds like it should be ok. The total advance should cover the 350.The system will run standard 4 ohm dual coils and will need 5k ohms plug caps, should already be on the machine.

t looks like the start of advance is ok, and the system will cover the fully advance figure. Our system reaches fully advance at around 3,500 rpm."




When I found that the DSS replacement coils were only 2 ohm I phoned BB and they told me I would need to run with ballast resistors.

...and this is how I fitted them.



This is the wiring diagram without ballast resistors.

[cb550k-aaron]

I Have one of the Boyer Bransden Mk3 kit but when it's all linked up it's only drawing 1v anyone any ideas?