I cant say exactly, too many different gennys, and I agree with Teddy and Jimbo HOWEVER the sum of BOTH field coils in series Id expect maybe around 2 to 4 ohms of resistance buttttttt as Jim notes a cheap meter isnt accurate at such low resistance. Still in line with Teddys great advice, if they show EITHER an open circuit orrrrrrrrr theres any short path (very low ohms)to the case frame, they are BADDDDDDD. Thats all insulated wire remember so its NOT shorted to the case
NOTE the armature needs to be out of the circuit or the brushes lifted or insulated cuz otherwise about everyplace shows a dead short to case frame via the grounded brush well duhhhhhhh
While this simple low voltage test shows if they are bad it dont necessarily show they are good cuz once warmed up and at higher voltages thats when they can break down even if the 2 tests above indicates they are okay (continuous and not shorted to case)
Often theres a short or an open where the 2 splice in the middle.