Mercury Force 9.9, 15HP Outboards Service Manual, Page 77Get this manual
4Turn crankshaft clockwise until index mark on cam lines up with fol lower arm (A) on breaker pointAd just breaker point openi ng to 0.020 in(0.508 mm ) Turn screwdriver in appropriate direction to increase or decrease gap openingTighten breaker point hold-down screws (Al Repeat procedure for other set of pointsRotate engi ne after setting points and recheck gap Clean points by inserting piece of paper between the closed points and pulling it through