Warming up

I own a 89 mazda b2200. Whenever I start my truck from a cold start the idle is really rough, yes i know it's carb and it will do this on cold start but i run extra gauges and one of the gauges happens to be a volt meter. The reading on the volt meter jumps around alot. I am new to carb so I just want to know if this is a normal thing or do i need to look into it. Any help would be appreciated. Thanks.

A volt meter should show slight fluctuation between idle and about 1500 rpm. After that, the alternator is putting out max voltage. If it's jumping around, you probably have a loose connection somewhere.

Ok thanks ill look into it