Topic: Transistor Ignition mods (improvement?) - opinions desired!

[HondaMan]

As much trouble as we are having with condensors lately....

I'm thinking about a modified version of the Transistor Ignition with condensors built into the box, such that they could still be used even if the box got damaged or shorted out (or something), not that many of them have failed (except for that batch of bad transistors I got from UK in 2010). These would replace the condensors in the points-plate area, and the "fallback" method, should the electronics die for some reason (EMP weapon?) you would just unplug the coils from the Orange and Purple wires and plug them into the Blue and Yellow alongside the ones already connected to the box - so, this version would require 2 more wires to be hanging out of the box, somehow insulated until needed. It would also push the cost closer to the ton mark, like $90, which seems a lot to me for such a simple gadget.

It would also make it unlikely (maybe impossible) that I could offer one with the Security Switch, as it will fill the little box right up inside.

Thoughts?

[flybackwards]

I think about things like - original design purpose and results, what happens when modifications are made to a successful design to include items which were not in the original scope and what complexities might result from the changes. Seems like a straight forward change but I think I would prefer to keep my condensers in the ignition housing.

I have built one of the boxes I got from you into my 77 K7 refurb and it fits nicely in the rectifier / fusebox space on the side panel which is vacant real estate due to moving the fusebox under the seat using auto fuses and the Rick's regulator / rectifier unit. I put a connector on it and made a harness going up the hill to coil land. I also made a shorting plug that goes into the harness plug instead of the ignition box if I want to go back to the points and condenser system for some reason - don't have to pull the tank. I am thinking that more wires on the box are not a good idea.

If the actual problem is bad condenser supply why not solve that problem directly - rather than modifying a successful design? A high quality Vishay .22uf 800 volt pulse capacitor is available for $2.95 Canadian in qty 100. Perhaps with some creativity something like that could be packaged to fit in the space available behind the points cover. I have not done the sizing precisely - but looks doable...

Maybe more after I sleep on it.

[PeWe]

I tested capacitors instead of stock condensors.
They did not last long until misfires over 5000rpm.

It is very hot inside the ignition cover. I'm sure the capacitors were not +100*C version.

About Hondaman ignition. I had thoughts about condensors inside its box as a good feature and avoid issues with bad condensors on plate.

The HM ignition runs fine without, except for additional misfires at higher rpms, after ~7000 if I remember correctly.

My K2 runs with it, TEC plate. Ignition box in tool tray where it sit dry and protected.

My K6 has one HM module  too with TEC plate, but currently running Dyna-S. No extra power seen on dyno when I changed ignition.

[HondaMan]

I think about things like - original design purpose and results, what happens when modifications are made to a successful design to include items which were not in the original scope and what complexities might result from the changes. Seems like a straight forward change but I think I would prefer to keep my condensers in the ignition housing.

I have built one of the boxes I got from you into my 77 K7 refurb and it fits nicely in the rectifier / fusebox space on the side panel which is vacant real estate due to moving the fusebox under the seat using auto fuses and the Rick's regulator / rectifier unit. I put a connector on it and made a harness going up the hill to coil land. I also made a shorting plug that goes into the harness plug instead of the ignition box if I want to go back to the points and condenser system for some reason - don't have to pull the tank. I am thinking that more wires on the box are not a good idea.

If the actual problem is bad condenser supply why not solve that problem directly - rather than modifying a successful design? A high quality Vishay .22uf 800 volt pulse capacitor is available for $2.95 Canadian in qty 100. Perhaps with some creativity something like that could be packaged to fit in the space available behind the points cover. I have not done the sizing precisely - but looks doable...

Maybe more after I sleep on it.

The problem with ALL electronic-grade capacitors is: at 400v rating, none that are available outside the automotive industry can handle BOTH the vibration AND the 200 degree temperatures on the points plate, at least not for very long. That's why this condensor issue is becoming such a problem these last 3 years.

(That's what PeWe, among others, have already discovered.)

[Deltarider]

When I had finished assembling my transistor ignition, I had improvised a location behind the RH side cover for a test ride: the device simply hold in place by the battery strap 'for the time being'. Guess what, it has remained there ever since (see pic). There has been no need to look for another spot ever, as the box has never moved a mm. Also it's a spot that doesn't see vibrations. Just have a look at the battery case with its six rubber dampers (2^nd pic) and you'll understand why.
The third pic shows a known good condenser that for example Velleman has chosen for its kit.

[HondaMan]

When I had finished assembling my transistor ignition, I had improvised a location behind the RH side cover for a test ride: the device simply hold in place by the battery strap 'for the time being'. Guess what, it has remained there ever since (see pic). There has been no need to look for another spot ever, as the box has never moved a mm. Also it's a spot that doesn't see vibrations. Just have a look at the battery case with its six rubber dampers (2^nd pic) and you'll understand why.
The third pic shows a known good condenser that for example Velleman has chosen for its kit.

The Velleman kit is where I 'steer' the Euro riders who don't want to pay import duties and taxes on mine. While it's a kit version, it's pretty similar to mine. Their 630v .22uF cap is a little less capacitance than the standard value of 0.24uF in the condensors normally used in our bikes and cars (of old!). The specification from the coil manufacturers universally call for a 0.22-0.26uF capacitance at 400v, which interestingly enough is the range of the standard metal-can condensors, all of them. That's why the little metal clips that will hold a tab-less automotive condensor should also work fine, provided there is room to mount them or maybe drill new holes to accomodate the little clips they use for holders.

[maxheadflow]

Dumb question here but why not mount the condensers on the coils away from the heat. Seems like you could use the caps that have issues with heat that way.  IIRC the HMs transistor ignition has caps across the transistor outputs.

[Deltarider]

Dumb question here but why not mount the condensers on the coils away from the heat.

Not a dumb question at all. If you look at all the connectors on our bikes, Honda did the utmost to make everything rainproof. I vaguely remember having seen footage of Honda testing their bikes on test strokes in pooring rain, to detect anything that could compromise reliability. I guess that's why Honda choose to mount them behind the ignition cover and not on the coils where you would need extra shielding.

[MauiK3]

I think the mod is worth trying.

[Don R]

 It occurs to me the gl1000 capacitors are mounted on the frame away from the motor.  I went with a dyna but left them there. I carried my points plate for a year or so just in case. Recently took it out of the fairing. 

[PeWe]

Someone here mentioned Mallory 400 condensor for US cars a year ago
I bought 2, possible to get it to fit inside a spacious cover. Better outside for longer life.

http://forums.sohc4.net/index.php?topic=7850.msg2112360.msg#2112360

[maxheadflow]

Dumb question here but why not mount the condensers on the coils away from the heat.

Not a dumb question at all. If you look at all the connectors on our bikes, Honda did the utmost to make everything rainproof. I vaguely remember having seen footage of Honda testing their bikes on test strokes in pooring rain, to detect anything that could compromise reliability. I guess that's why Honda choose to mount them behind the ignition cover and not on the coils where you would need extra shielding.

IIRC the condensers on the 350s / 360s / 450s were mounted on the coil.  Old issue with them was the coil mounting coming loose and them not having a good ground. They'd miss real bad.

[HondaMan]

Dumb question here but why not mount the condensers on the coils away from the heat. Seems like you could use the caps that have issues with heat that way.  IIRC the HMs transistor ignition has caps across the transistor outputs.

Yes, the heat was one of the big reasons (plus Delta's observation above) that the condensors got moved away from where the coils are now. While not true in city traffic (slow), the heat under the fuel tank on the 750 is not bad when the bike is moving along. This was one of the design criteria for the Vetter fairing (and viturally no others) when the Windjammer was being developed, because the Phantom (its full-length predecessor) was heating the coils and fuel tank quite a bit with its small engine opening. (Although this opening did a great job of stopping the outer 2 cylinders from warping as they cured!)

Prior art had been to locate the condensors off the engines directly, and for the 750 TEC developed a special epoxy-capped condensor (which, if you have some, are still good today for the most part) that would withstand the anticipated 300 degrees of the engine, which became an actual 240 degrees peak on 100 degree ambient city-riding days, as it turned out (I have evn tested my own, in 2007, and it concurs with these numbers). But, this is 40 degrees (F) higher than typical electronic capacitors can withstand before they suffer internal damage.

One COULD use the condensors from Honda for the 350/360 twins of the era (same capacitance), mounted on the coils, since the design turned out to be OK anyway. Clumsy, but they would work. Don't try it with the Daiichi versions, though, or you will be disappointed, quickly.

The ones inside the Transistor Ignition can't be used by simply disconnecting the Transistor Ignition's (Black) power wire because the back-EMF voltage from the coils would partially power the final-stage transistors, shunting and severely shortening the spark from the points in the process. But, if I add 2 more independent ones inside and tie them to a pair of Blue and Yellow wires (with opposite plugs from the existing ones to prevent misconneciton troubles) they would fit, if using up the remaining space inside the box at worst. This will NOT be possible with the Triples version, though (like for the GT750, Kawi triples and the rare Yamaha 750 triple, of which some sport my boxes today).

[HondaMan]

Dumb question here but why not mount the condensers on the coils away from the heat.

Not a dumb question at all. If you look at all the connectors on our bikes, Honda did the utmost to make everything rainproof. I vaguely remember having seen footage of Honda testing their bikes on test strokes in pooring rain, to detect anything that could compromise reliability. I guess that's why Honda choose to mount them behind the ignition cover and not on the coils where you would need extra shielding.

IIRC the condensers on the 350s / 360s / 450s were mounted on the coil.  Old issue with them was the coil mounting coming loose and them not having a good ground. They'd miss real bad.

Aye!
And, today we see lots of corrosion on those mouting bolts/screws, which can sometimes magically "fix" that same trouble when they are just cleaned up and oiled a dab.

[maxheadflow]

I'll bring up another naive question.   

On a transistorized ignition, do you even need a cap/condenser?

When using points, the cap is there to prevent arching at the points.  I've seen old automotive manual someplace that basically said the value of the cap should be based on how the points transfer metal at the contact point.  When the cap is the right size, no transfer.   This means that the cap is there to control the collapse of the coil at an exact rate to minimize arcing at the points.

With a transistor switching the coil, the switch is solid state and no arcing occurs.  The only thing to worry about is the peak voltage that the collector sees.  New ignitions don't have caps that need replacing so I expect that they don't even have caps across the coils..

I would guess that the cap does help tune a older higher higher impedance coil so that it's peak oscillation is optimum?

[Deltarider]

You can have a transistor ignition without a capacitor, resulting in an even steeper rise time which is good. But, still having the mechanical breakers for switching the control current, eventual bouncing cannot be ruled out, which would trigger multiple sparking.   

[PeWe]

Hondaman ignition is an add-on to stock points with condensors due to the points.

All other electronic ignitions have no need of external condensors, no arc over points to take care of. It's like a filter.

Dyna-S use stock advancer.
Dyna 2000 no stock advancer used.

Upon this several others like Dyna-S.

Good idea to buy fresh coils when replacing the ignition. 40-50 years old coils with degraded isolation can cause a stop.

[maxheadflow]

Hondaman ignition is an add-on to stock points with condensors due to the points.

All other electronic ignitions have no need of external condensors, no arc over points to take care of. It's like a filter.

Dyna-S use stock advancer.
Dyna 2000 no stock advancer used.

Upon this several others like Dyna-S.

Good idea to buy fresh coils when replacing the ignition. 40-50 years old coils with degraded isolation can cause a stop.

Yeah I know. But are they even needed?  The transistor reduces the current across the point gap and maybe even the point gap voltage.  No coil feeding back to the points to create a high flyback voltage.

[PeWe]

Yes, no condensors with HM ignition = additional misfires at higher revs.
I think +7000rpm  if I remember correctly.  I have tested.
Possible to ride.

[ANDREAS MILKE]

Deltarider:

The metal box for your Lecetronic Ignition is a 1590B Hammond box?
I use this box to make my own Electronic ignition.

[maxheadflow]

Yes, no condensors with HM ignition = additional misfires at higher revs.
I think +7000rpm  if I remember correctly.  I have tested.
Possible to ride.

IIRC there are caps across the output of the transistors inside the box.  Are you saying adding caps makes it miss?

[RAFster122s]

Max, I am pretty sure PeWe means, without the condensers being used the HondaMan Electronic Ignition box can have misfires above 7k rpm.

[bryanj]

Talking points bounce many years ago i made an electronic tacho for a Royal Enfield 250 single and at anything over 4000 rpm it went crazy due to points bounce but the engine ran fine, or at least as well as they ever ran!

[Deltarider]

Talking points bounce many years ago i made an electronic tacho for a Royal Enfield 250 single and at anything over 4000 rpm it went crazy due to points bounce but the engine ran fine, or at least as well as they ever ran!

Not impossible, Bryan. In principle mine can switch up to 500 kHz. I could give it a try without capacitors to achieve an even steeper rise time, but I would possibly see very high, maybe erratic RPMs whenever I connect my electronic tach meter.

Deltarider:
The metal box for your Lecetronic Ignition is a 1590B Hammond box?
I use this box to make my own Electronic ignition.

Mine is the 100 x 50 x 25 mm Hammond, but... it was a bit hard to squeeze the two prints in. I had to shorten the three pins of the TIP162s*, bent them real close towards the print and used the box and its lid to 'cool' the 'back' of forsaid transistors. The little screw that fastens the transistor, protrudes in such a way, that the unit is in a somewhat angled position to the battery, which prevents the box from sliding downwards. In all those years it has not moved a mm. I believe there is enough room behind the RH side panel for an even bigger box like the one you need. Your allumage looks very interesting. Keep us posted. The in red indicated 150, are those Hz?
* For a friend I am assembling a new set that has the BU931P.

[maxheadflow]

Max, I am pretty sure PeWe means, without the condensers being used the HondaMan Electronic Ignition box can have misfires above 7k rpm.

On the input or the output to the box?