So let me give a brief history of my problem - the last time I rode the bike in 2008, the engine burned oil and 1 and 4 cylinders were not getting a spark so the bike sat in a garage until last January. Since then, the engine has been rebuilt. It appears the oil burning problem was too much clearance between valve guide and valve at the No. 2 intake valve. The spark problem is unsolved. After the engine was rebuilt and the carbs and ignition settings completed the engine started and idled nicely, but the first ride lasted only 1-1/2 miles before the engine was running rough which turned out to be carbon fouled plugs. It turned out that I had the float level in the carbs too high. After resetting the float levels, I could get maybe 30 miles on the odometer before the engine was running rough again due to fouled plugs. After cleaning off the plugs for the next couple of 30 mile rides, I decided to do some research which included the KZRider Forum and learned that a weak spark could also cause fouled plugs. A check of the plugs taped to the top of the cylinder head confirmed the sparking was less than desirable. I also learned that during the engine break-in period I should have been using the hotter B7ES plugs as my shifting gears at 4000 rpm was basically lugging the engine. i replaced points and condensers - rode the bike with the same results - replaced the coils - rode the bike with the same results, and finally replaced the B8ES plugs with the B7ES plugs and rode the bike for approximately 15 miles where during that ride the engine ran rougher and rougher with the last 5 miles the engine misfiring more than it fired. At this point I am totally frustrated and decide to start at the beginning. For the carbs, I lowered the needles to their leanest settings and started from scratch setting the points and timing - and this brings me to my problem that I hope someone can help with.
When I was setting the timing (getting the points to open on the "F" mark) the ohmmeter needle always showed a closed circuit as I observed the points open and close. I disconnected the points and condensers from the wires to the coils, and points and condensers checked out ok . Working my way back up the ignition circuit, I found that the circuit was grounded until I unplugged the Brake Light Failure Indicator Switch. This switch has a 3 pin connector, and I found that the 3 wires coming out of the switch all showed continuity no matter which 2 wires were selected. So my analysis is that the black ground wire to the switch is grounding the ignition circuit thru the Brake Light Failure indicator Light. This light and the ignition circuit share the same power wire.
I have researched the wiring diagram for the Brake Light Failure Indicator Switch and do not understand what it's telling me. My understanding of electrical components and their characteristics is minimal when you get into diodes, etc. What I am hoping is that someone can tell me if my switch is bad and shouldn't be grounding out the green wire that connects to the indicator light or if the switch is good. If the switch is good, then I guess I need to keep pulling apart wires until I find the source of the ground.
My process for checking components is to see if I get continuity between any component connection point and the metal case of the engine. Before starting my search for the ground, I took the battery out of the bike, disconnected the black/yellow ground wire from the engine case and unplugged the brown plug at the electrical panel to isolate the alternator, regulator, and rectifier. My ohmmeter is set to the highest scale. I'm using the wiring diagram for the KZ900 - A4 in my book. Any help would be greatly appreciated!!