I was looking at the wiring diagram in the manual again thinking surely they would somehow indicate which wires go to which coil and surprise surprise, they do in an offhand sort of way. In the main wiring diagram color codes there is no Gy2 however there is a Gy which is gray. I guess one is supposed to know what the 2 stands for which is the number 2 front cylinder right coil and that matches exactly with what Stinger wrote about the wire connections. At least that's the only reason I can figure for having a 2 after the wire color.

Scott B.

That gy goes from the ignitor to the pickup coil. The gy2 come from the other end if the ignitor (actually the next wire down from the orange wire) to the right side coil. The drawing is a little confusing in that the coils as drawn are actually inverted & the right side coil faces to the rear of the bike. I went out & looked under the tank to see which side the orange was on & where it was located on the coil relative to the bike. Hope all that makes sense.

Scott, Stinger, Thanks. Very helpful. Turns out I had the wires on the right side reversed...at least I think. I gotta put a charge on the battery, again, then I can try, try again. To make sure I got this correct: on the right side coil the gray goes on the outside terminal and the red with black strip wire goes on the inside (next to the frame)?

really doesn't make a difference, those wires are going to the primary coil, and all really a coils is, is wire wrapped around a metal, the expanding and collapsing field of electromagnetism is what causes the secondary coil to get the voltage

I tried to see the coil on the right side, but it's almost impossible without pulling the tank all the way off since the right coil is facing to the rear of the bike. That being said, it LOOKS like the outside wire (away from the frame) is red down inside the plastic connector. However, looking at the schematic, it should be on the inside next to the frame. How about trying it one way, then switch them if it still won't start. I'm SURE about the left side, so at least it's down to 1 coil. Erbman may be right, it might not make a difference, but wouldn't having the primary & secondary reversed on a coil keep it from firing? Tell me if you're still having problems & I'll pull the tank to be sure.

I was just going by what a Yamaha Rep told me once yet knowing how a coil works I don't see how it could make any difference either. Stranger things have happened though.

I'm more concerned about your description of the rear cylinder only firing every 4th revolution. If the timing is right and anything is firing at all it seems like you would get some kind of combustion. If you've got the right amount of air, fuel and fire at the right time then something should go bang.

Scott B.

Yeah! This is fun. I tried the wires every which way and nothing works. I am sure I have the correct connections. Still same thing. I put a signal testor in the plug wires and hit the start button. The rear cylinders give a signal every revolution. The Front cylinders are hitting every fourth revolution.

The only thing I did differently is install the HD hand controls and switches, and the digital speedo/tach/dash. I followed the schematics to the wire and still have no luck. This bike is like my wife...great to look at, but won't let me ride.

These bikes will run on one cylinder. Anyone who has experienced a stuck valve can attest to that. They even start with the decompression system holding the exhaust valves open.

By signal on the rear cylinder I assume you mean a spark. Once per revolution is normal. How is your tach hooked up? Normally you just add a wire to one of the coil signal wires.

The rear cylinder may be providing a spark but is it at the right time? About the time it sparks you should get a blast of air out of the spark plug holes. Have the cams been replaced and possibly timed on the wrong stroke? Are the pushrods on the right cam lobes? And I think you did say it was getting fuel.

It's hard to do this long distance, wish there was someone there who could help you. Don't give up, i'm sure there's someone out there who will come up with the right clue to fixing this. I'll keep trying too.

Scott B.

stinger wrote:
Erbman may be right, it might not make a difference, but wouldn't having the primary & secondary reversed on a coil keep it from firing? Tell me if you're still having problems & I'll pull the tank to be sure.

There is zero wire connection between the primary coil and secondary coil. The only item attached to the secondary coil is the spark plug. The primary coil induces a expanding and collapsing electromagnetic wave form, this energizes the secondary coil and steps up the voltage, when the voltage is high enough it ionizes the gas and becomes strong enough to jump the spark gap(spark) and starts all over again.

Here's a diagram of an ignition coil system I found on the web. At the bottom of the windings there is a connection shown. The windings must be connected internally. However, what I was trying to point out is there are more windings in the secondary than the primary, therefore if 12v. is applied to the wrong, (negative instead of positive side) the coil won't fire because there are not enough primay windings to generate a high enough current to jump the gap on the spark plug. I've actually seen this done on a car. It didn't work very well.