Thinking about picking up a Bosch FIX7677 multimeter. First order of business is to measure and set rpms on my CM200T ‘80. Instructions make reference to attaching lead to negative side of coil. Wiring diagram is showing a blue and black/white feeding the coil, would I be connecting to the blue? Also, can the coil be accessed without removing the tank? And finally, does anyone have experience with this Bosch meter or a different recommendation? Appreciate any input.