Yeah, but if your gun can be set to give you advance, you should be timing it by the tdc mark and not the +15 degree mark is what I'm trying to say - the +15 degree mark is there so that you can set the timing with a gun that has no advance/is always set to 0 degrees.
So in your case, if you want 17 degrees then set your gun to +17 and use the strobe to adjust the dizzy so that the tdc mark is in line with the pointer. Then when you set the gun to 0 degrees, you should be able to use the strobe and see the 15 degree mark is a couple of degrees off the pointer.
By the sounds of it, you set your gun to +17 degrees and set the timing using the +15 degree mark... Won't this mean your timing is actually set to +32 degrees
I've only timed up my Golf which has no advance markers, you set the base timing with the vacuum advance off, but I'm hoping somebody on here can clarify if what I'm saying is right
