Id say the value is "fairly" critical. If its too high she may not fire at all while if its way too low (or even open) she can still fire (weaker spark) but the points will burn up sooner. Unfortunately I have no specs or data as to what that engine uses, sorry.
An analog ohm meter using the kickback test can give you an indication of the condensors characteristics and can show it its definitely BAD (shorted out etc) but not if its good and not its capacitance. For that you need a REAL capacitor tester.