Tachometer
 

The tachometer in my 81 RX7 has started to act a little funny. Sometimes it works and other times it doesn't. Is there a possible fix for the problem that won't require removing the combination meter assembly? Apparently, some of the gauges within that assembly can be replaced once the assembly is removed but I'm not sure if that also applies to the tachometer. I also posted this question in the 1st generation area but so far there are no responses there.