Resistance across rotor rings

Hi Guys. Still trying to get this Maxim to run on its own electrical power instead of the battery. Haven't worked on it in ages (life happens). Anyway, finally got the time and inclination to start working on it again yesterday. And finally got a multimeter with a zero adjust.

According to my Clymer, I should see 4.5 ohms resistance (+/- 10%) at the green and brown wires that lead to the regulator. My reading fluctuates but it's more like 6.5, so clearly out of spec. So I'm measuring all thru that circuit trying to find where the culprit is, and of course I see resistances everywhere, even across the brushes themselves.

Now here's the part that makes me feel stupid: I measure 4.5 ohms exactly between the two rings on the rotor, which is exactly what my total resistance should be, so I'm trying to find zero resistance everywhere else. I finally read a bit further in the Clymer and it says there should be "low resistance" across those rings, and that "Yamaha does not provide an exact spec".

So... is my rotor bad, and it's reasonable to see a couple of ohms resistance thru the brushes and harness, or should I see close to zero resistance thru the harness and brushes?

Thanks in advance!