I just got mine, and from reading the manual, it says if you have a metal flywheel (most do) then put the non-reflective sticker on the backside facing the engine and mount the sensor with the included aluminum mounts onto the side of engine mount and put sensor about 1/8 inch from the flywheel. There are really good pics of mounting options in the manual. You might have to use just one screw on sensor board to move the sensor around so its close to the non-reflective dot.