No spark? Maybe the points need cleaning/resetting? Coil could have gone kaput..
I just turn the motor by hand,watch them and ensure they are opening and closing,and then set them to .020 at the point where they open the widest,you can watch the little push rod and tell when it starts going back in..I'm not sure in .020 is the correct spec for a HH Tecumseh,but it works for my HH120's and all the others I've fooled with...