It does sound a little vague. The bank of injectors is on the back side of the head and that stepper motor and its components are tucked in between 2 & 3. It helps to have a longer straw on whatever spray you are using. You are sort of "flying blind" spraying it in there , because you can in no way see the area you are trying to hit. But I took my tank off the first time and made a mental note of what I would need to hit in event it was needed. I've helped 2 other riders just knowing the area , and spraying what looks like randomly in the area. That make any more sense? You will/would be spraying in an upward direction , but more like you're trying to hit the the back of the head and slightly toward the tank than directly at the bottom of the tank.