I've bought a 6v to 12v conversion kit last week from Rex speed shop. And have started to fit, all quite easy until I removed stator there is a brown wire that connects ignition coil to the lighting coil. See photos attached. According to the workshop manual the coils are not connected in any way. Does anyone know what to do with this brown wire?

All I know for sure is that many models had the coils connected.  I have a pretty good guess, but this is really a question for Rex's.  Good luck.

Maybe someone here has had the same situation with that kit and will comment.

How did the conversion work out? I am purchasing the same package from Rex's for my 175E. 

I cannot finish the till i know what to do with the brown wire that is connected to both coils, nothing about it in the rex instructions.

Wondering what Rex will tell you.  I searched the forum and found several questions and issues but not that exact one. 

Anyway, you mentioned that wire wasn't mentioned in the manual...  just FYI, that wire is clearly shown in the parts diagram so don't let anyone say it's not original or something...

 


Several models connected the ignition source coil to the lighting coil.  Magnetos seem to run on black magic...  look super simple but the engineering is very complex...  I've spoken to a couple of very smart Electrical Engineers who told me that designing points magnetos like Yamaha used is a very specialized field and probably close to a lost art.  More modern systems are just basically permanent magnet alternators that power electronic circuitry.  Much less complex in terms of engineering.

Anyway, presumably the connection to the lighting coil increases available spark energy.  Will it have spark without that connection?  Almost certainly as long as the wire is grounded well. 

Hopefully Rex's will give you a solid answer on what to do.

I wonder if it is a bit like a cdi having a high speed coil to boost spark at revs. All i know is mine is earthed separately but don't have a lighting coil Maybe all these years i've been missing out on top end performance. I know on my 490 with a crook high speed coil that piggy backed to the main source, i removed it & ran a simple box of a yamaha old scooter & wasn't ever an issue. But now i wonder!! what i missed out on. Always new 'old' things to learn.

Spark only has to be "good enough"...  power is really only lost if mixture doesn't ignite at all. 

Thanks for your replies, but still non the wiser ,sent the question to rex speed shop tech help via email on Sunday no reply yet so still no progress,

How did you go with this issue?
I did the same conversion a few years ago and had the same problem.
From memory Rexs advised me to simply cut the brown wire.
I can take my stator cover off tomorrow and take some photos.

Yes finally sorted the problem the brown wire is an earth from the ignition coil, so leave as long as possible cut the wire strip and solder a round terminal to the wire and place under screw that holds ignition coil. (Bottom) screw. This should solve the issue.