Jo- the rotor had a round spot I thought it was a carbon deposit. it was on the piece that is about 1.5" ling. What does that mean? is the rotor the issue?
The round spot on the rotor strap is from the button on the inside of the cap (normal)
What is meant is to take the rotor off and closely look inside it, and at the top of the shaft it goes on.
Every once in awhile the spark will work it's way right through the center of the rotor to ground. (the shaft)
Then the spark does not go to the plugs any longer, but just jumps to ground through the rotor.
Usually the dead giveaway is very small burn marks on the top edge of the shaft.