Motorcycle Repair: 1977 dt 175, test light, gap

Question
I rebuilt the engine installed it back in the bike set my points at 30 my test light pulsates when i crank it over up to the coil but nothing after it i replaced the coil and still no spark did i set my points wrong  their are 4 wires coming from the mag the only one that pulsates is the black wire the battery in new and has a full 6volts

Answer
I may be wrong on this and if I am I will stand corrected.Try setting the points at about 0.16-0.19 thousanths. To wide a gap changes the timing also.And check the wire on the points sometimes the terminal it bolts to will ground out also causing problems.