Loudhvx's ignitor diagram

That looks really well done.

If you have it opened up some time, you may want to put a dab of 100% silicone sealer on the resistor and diodes to support them against vibration. Discrete parts tend to vibrate on the ends of their leads enough to break off the leads. I either wrap the parts in tape or put on a dab of silicone to dampen the vibration. It is important that it is 100% silicone. Any latex sealer will conduct electricity.

Very nice job!

Thank you very much for the compliment and thank you very much for the idea of using the modules in the first place and the help you provided.

The box is just resting behind the battery carrier, so not fixed to the structure of the bike, so I hope I will not get too much vibration there, but I will see when I have used it for a bit and will give the module a check over. At the moment it is a bit cold in the UK and we had quite a bit snow as well, so the trials are limited to running the bike on the patio. I can’t wait for some warmer weather after some good rain, which should clear the roads of all the salt they have put down. This really messes up the bike.

Thank you again, cheers

When I was in the USAF we used the silicone RTV compound to encapsulate diodes and resistors for delicate electronic bits in wing pylons on aircraft like the one in my avatar(F-4E) It provided moisure and shock resistance.

One last thing. It's not really an issue if its working properly, but the ground on those modules is the actual heatsink pad on the module. The heatsink compound can act like an insulator. Normally this is not a problem because the mounting bolt will go through and contact the back side of the heatsink. However, in your design, you have both sides of the heatsink covered by a module. This means there is a slight chance that the mounting bolts may lose their ground contact. If this happens, just put a wire lug on one of the mounting bolts and run a ground wire from that to the ground in the harness (or battery ground).

This is a good point. By me putting the modules in to a plastic box and resting it behind the battery holder, the whole thing is not connected to the frame at all, but still working though. I better take it out again and run a ground to the modules. Thanks god it is Sunday.

Now I got confused and worried about nothing. I looked at your diagram again and can answer my own question.
The yellow/black cable in the ‘GM HEI Ignitor Substitute’ diagram is ground already and the way I have connected the two modules together is via the bolt(s) holding them on to the aluminium bracket. On the other side there is a solder point under the nut, which has the yellow/black cable solder on to. So the ground is provided to the modules via this cable.

To verify a ground, put a multimeter set on ohms, one probe on the negative battery post and the other on where your ground wire for the modules go. This should have continuity between these two points.

Schorly wrote:

Now I got confused and worried about nothing. I looked at your diagram again and can answer my own question.
The yellow/black cable in the ‘GM HEI Ignitor Substitute’ diagram is ground already and the way I have connected the two modules together is via the bolt(s) holding them on to the aluminium bracket. On the other side there is a solder point under the nut, which has the yellow/black cable solder on to. So the ground is provided to the modules via this cable.

Yeah, sorry about that. I just couldn't see it. It is just hidden on the backside of the modules in your photo? That should have you completely covered then.