06-02-2015, 11:52 PM
You back probe the signal wire coming out of the oxygen sensor (HO2S). Leave the sensor connected to the harness. I use T50 t-pins from a sewing store when I can't find my $35 Snap-On back probe. I don't have a wiring diagram, but checking voltages won't let any smoke out. One wire will be power for the sensor heater. There will probably be two (2) ground wires. Heater ground & sensor ground. The final wire will be signal. On a fully warmed up engine, the signal wire should be bouncing between 0 & 1 volt. Slip the back probe through the weather-pack seals of the connector. It doesn't matter from which direction so long as you get a good connection between the back probe and the wire terminal. Twist tie the meter leads to prevent them from contacting the exhaust, moving parts or anything else that could harm them, you or the meter. Although I've never mapped a M/C HO2S, I vision the meter being on the seat between the rider's legs or where ever you can see the meter and press the min/max/average button. If you've never min/max/averaged before, remember you need to start the measurement & end the measurement without any significant accelerations (acceleration enrichment) or decelerations (decel enleanment). Just like a DOT drug (urine) test, capture the sample midstream while at a nice steady throttle on a level road. Straight is nice, but as long as you can maintain a steady throttle, not mandatory.