need to fix my yamaha dt 400 1977 model?

bike was cutting out so i took the carb off and thourghly cleaned it. put back together fired on first kick and then it died after 30 sec. cuoldnt get it restarted so i checked the plug and coil and iwas not getting any spark so i went to the salvage yard and found a ciol it tested good i put it on my bike and it started on the first kick and then the same thing happened after 30 sec. it died and wouldnt restart and i dont seem to be getting any spark again