With the plugs sparking try both #1 & #2 because they are seperate circuits and if one of them isn't working then the engine possibly won't even sound like it wants to start.
My K1100LT had one plug lead off and it just didnt even come close to starting.
First thing I would try with the injectors is to put the handle of a screwdriver in your ear and the tip on the steel body of the injector and crank the engine, you will probably hear a slight click as the injector activates on every revolution of the engine. If you can get to them try it on all four.
If you can hear the click you know the electrical circuit is working. I would then undo the two bolts and remove the injectors and see if they are releasing fuel when they click. Try to do each injector into a small container and watch the spray of the nozzle, the fuel should come out as a fine mist not a squirt.
If the fuel does not spray well get them serviced.
If that is all ok then test the compression but usually compression doesn't just drop off suddenly.
If you do remove the injectors replace the O rings as they often leak after being disturbed. They may have never been out before.
The plugs will fire without the little screwon caps but you will find the leads don't stay on and the capson the leads will erode because of the sparking and will eventually fail.
