I made dual plug conversion to my friend's r100gs but I have a problem with the coils. I have the same setup on my G/S and never have any problem since I did it(10k km).My knowledge about electric works is limited and I need your advice. I used PVL coils, two ICU and this wiring diagram. The only thing that is different on my friend's bike is we used the type of plug cable in the photo below. A while ago the left coil had a little crack and I covered it with sealant(thats why it is black) to see if it works or not . . This is the result So what's the matter with these coils ?
Does the ICU shutoff power to the coils if the ignition power is left on? The coils look as if they are overheating. Why are you using 2 ICUs for dual plugging. I would use one ICU and wire the coils so that they both fire together. I would not use the BMW system, but do it properly with a Sachse or Silent Hektik ignition.
First of, wrong plug wires. You want to use solid copper core wire, never carbon "supression" wire. Then you either use a resister spark plug cap and non-resistor plugs, or a plain cap with resistor plugs. The coils look like they have overheated badly. Incorrectly wired, wrong resistance or there is something wrong with them. I don't understand why you are using two ignition modules. One is plenty. You do not get more reliability. You have to think about that one carefully. But the resistance of the coils must be correct. If you are using a standard ICU and standard coil wiring, I can tell you the value. Typically the coils are 6 volt units wired in series. That is, the power goes through one coil then on through the other then to ground through the ignition module. The output (spark plug side) of the coils is crossed over so each coil feeds both sides. On my dual plug setup I have the right coil feeding the upper plugs and the left coil feeding the lower plugs. Not knowing the specs of the coils you have, I cannot say if they are appropriate.
Coils are PVL specs ; High voltage supply: > 21 kV Max. spark energy: 30 mJ Primary resistance: 0.6 ohm Primary inductance: 1.65 mH Secondary resistance: 8.7 kOhm Secondary inductance: 9.2 H http://www.pvl.de/content/tpl_a.asp?lingo=english&ident=6&ID_content=149&URLSubb=143 Plug caps are NGK LB05FP
I have had these PVL coils overheat and fail too, and have had several reports of them overheating in other bikes too.
Don't feel like looking up those NGK caps to see the specs. Your caps, you look them up. With the stock ignition, circa '83 and '84, and using one module, you use a pair of dual nose coils, wired in series, with a primary resistance of 1.5 ohm. I'm using Dyna Brown coils. The lower resistance coil, which will draw more, was used with later ignitions. See Antons page here. Note the bit about the module having a cut off function to shut down the coils if the bike isn't running to avoid over heating them. You can get solid copper core wire with a nice silicone jacket, in a couple sizes and colors. Looks like an oil cooler at far right in the picture? it's dumping heat right on your already hot coils. Not good. Try putting it back on the crashbar and then protecting it. Do not mount it too hard. Also lay the bike over on the crashbar and see what touches down.
