I have an old either 80 or 81 that I am trying to get in time I have the T mark but rotating the wheel counter clockwise shows numbers leading to two marks seperated by approx. 1/2 in. is this where it should be timed? It will start {hard} and run but smokes a bit and the idle is erratic

 

Finally found the F and got her in time. Eyes aren't as good as they once were.