Just to review the main points. You appear to have spark and fuel(wet plugs) and the injectors are pulsing. I'm not sure how much compression you have, Chris Harris advises adding some oil to the cylinders of an engine that hasn't been run for a while to get enough compression to start.
Assuming you have enough compression, the only other things that could prevent starting are bad ignition timing(very unlikely unless the mounting plate for the Hall Sensors is loose), flooding by an overly rich mixture, an overly lean mixture or weak coils.
A quick look at the Hall Sensors will tell if they are not loose and the timing is close, these engines seem to run okay over a fairly wide range of ignition timing. There is a circular cutout in the Hall plate that aligns with the surrounding engine. As long as that cutout is approximately aligned the timing will be close enough to start the engine.
A rich mixture can be caused by a faulty temperature sensor, excessive fuel pressure, or injectors stuck open. If the mixture is too rich and flooding the engine, I would make sure I have a fully charged battery capable of cranking the engine for an extended time. First, I would try to start the engine by cranking for 4-5 seconds. Then, disconnect the fuel tank connector and crank again, this time for at least 10 consecutive seconds maybe longer. Count it off to make sure you crank long enough. What you are doing is pumping the excess fuel out of the cylinders. At some point, the amount of fuel remaining will be enough to fire once or twice. It won't actually start the engine, but it will confirm that the engine is not getting a proper mixture.
On the other hand, it is possible, but unlikely, the mixture is too lean to fire. On other engines, I have put a shot of starting fluid in the intake. If the engine fires, that shows the mixture as too lean. While I've never done it with the brick engine, I would guess that I would try to put a good shot in the air box through the opening for the snorkel while the engine was cranking. Try it both with the fuel tank connected and disconnected. A lean mixture can be caused by blocked fuel passages or faulty temperature information.
I see that your bike is a 1985. It is known that the early K100's had coil problems. It is possible that your coils are weak enough that they cannot supply enough voltage to spark at the top of the compression stroke on wet plugs. Beyond replacing the coils I don't know exactly how to see if that is the problem. The only test I could think of would be to close up the spark plug electrodes by .010" or so and try starting the engine as described for the rich mixture test.. My thinking here is that a smaller plug gap might be easier to spark under compression with weak coils. If the engine starts, it probably means that you need to update with later model coils.
Hope this helps.
