Hiya, Match.
I see two points of disagreement here. First, a bit of terminology - the FZR does NOT have a CDI box. It has a TCI box. I know it's common usage to refer to the electronic ignition box of any vehicle as 'the CDI', but it's incorrect and - especially in a case like this where we started off talking about using CDI coils with a TCI controller - a source of confusion and potentially damaged parts.
Second, the orange and grey wires between the FZR TCI and the coils ARE major current paths. For most of the crank's rotation, current flows from the battery to the main key switch to the primary coil (R/W hot wire, R/B on the '06+ R6) to the TCI (O & Gy wires on the FZR) to ground. When the Black Box decides it's time to fire a spark, it opens an internal switch (turns off a transistor) which stops the flow of current through that particular control wire, collapses the magnetic field around the primary coil, and induces major voltage in the secondary coil which throws a spark across the plug(s). I did refer to it as a 'signal wire' in my previous post; after more thought, I'd suggest 'control wire' is more accurate. I strongly believe the resistors are critical to preventing a fried box, especially with the CDI-type coils currently wending their way to my doorstep. If you were to wire two '06+ TCI-type coils in series, I would agree that resistors are not necessary, but you may or may not get enough current flow to sufficiently saturate the coils to throw strong sparks, especially at high revs (more critical on my screaming little beast than on your loafing middleweight
)
I have seen two wiring diagrams for the FZR600. The .gif file by Naeslas, oft referred to on FZR Archives, does show two grey wires coming from the TCI. The official Yamaha service manual, also avail on the Archives, shows one grey wire that splits off between the 2-3 coil and the tach. The link below takes you to the table of contents; you want chapter 8 part 1.
http://www.fzrarchives.com/ipb/index.ph ... opic=36296
It is possible that Yamaha made an error in their manual, and that Naeslas physically traced the wires. Since the same wiring arrangement is shown in the 400 manual, I'm more inclined to go with Yamaha's version (short of going out, digging the bike out, and spending a few minutes tracing wires
).
There is no logic or control in the coils; they are lumps of iron with wire wrapped around them. There is no 'signal' pulse from the Black Box, be it CDI or TCI. Current is either normally on then chopped (TCI) or normally off then pumped (CDI) through the wires from the Box to the coil.
You may have a point about the fuse. I think I'd put it inline with the resistor in the O & Gy wire paths; directly protects the TCI box...
