That's not how a hall sensor works, it doesn't generate voltage. It acts merely as a switch, opening and closing a circuit as the magnet passes. There is actually a dozen or so components inside the little chip that is a hall sensor on a Rcexl or C&H ignition. I've never spent the time to figure out whether one could be tested accurately with an ohm meter.

I wrote this troubleshooting guide for testing Rcexl ignitions, the sensor is tested in the process, it will work for most C&H ignitions also.

<span style="LINE-HEIGHT: 115%; FONT-FAMILY: "Verdana","sans-serif"; FONT-SIZE: 10pt; mso-fareast-font-family: Calibri; mso-fareast-theme-font: minor-latin; mso-bidi-font-family: Arial; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA">Take an old expendable servo extension and cut off the male plug end, separate the wires, strip a bit of insulation from each of the 3 leads and plug the other end into the sensor lead on the ignition module. Put a good CM-6 plug in the cap, doesn't need to be all the way seated but far enough for the hex of the plug to make contact with the metal shell of the plug cap, plug a fully charged 4 cell battery directly into the ignition. Test for battery voltage at the red and black wires of the test extension you made and plugged into the sensor lead of the module, if there is no voltage replace the module, if there is battery voltage......Short the white and black wires together, every time you break this connection there should be a spark, no or intermittent spark=bad module, has good spark......Remove the test lead and plug the sensor on the engine into the module and turn the engine over, no spark, replace the sensor, good spark.... Remove the spark plug, look down into the plug cap and turn the engine over, if you see spark arcing through the silicone boot to the metal shell, replace the spark plug cap, no visible spark but you hear a snap.....Put a small screw driver into the bottom of the cap, turn the engine over and you should observe spark jumping from the screw driver to the plug cap shell outside of the silicone boot, an arc of about 1/4"-3/8", if it does this there is nothing wrong with the ignition, if you hear an arc but it's not in the cap with the screw driver it could be a problem with the </span><span style="LINE-HEIGHT: 115%; FONT-FAMILY: "Calibri","sans-serif"; FONT-SIZE: 11pt; mso-fareast-font-family: Calibri; mso-fareast-theme-font: minor-latin; mso-bidi-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA; mso-ascii-theme-font: minor-latin; mso-hansi-theme-font: minor-latin; mso-bidi-theme-font: minor-bidi"><span style="LINE-HEIGHT: 115%; FONT-FAMILY: "Verdana","sans-serif"; COLOR: black; FONT-SIZE: 10pt; TEXT-DECORATION: none; mso-bidi-font-family: Arial; text-underline: none">resistor</span></span><span style="LINE-HEIGHT: 115%; FONT-FAMILY: "Verdana","sans-serif"; FONT-SIZE: 10pt; mso-fareast-font-family: Calibri; mso-fareast-theme-font: minor-latin; mso-bidi-font-family: Arial; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA"> in the cap or the high tension lead where it goes into the cap, replace the plug cap.

All of this can be done on a bench, the plug does not need to be grounded to the engine.</span>