the fuel filter on my old jeep is a metal type filter,
it has one inlet in and two outlets out:
the outside outlet is to be positioned at 12:00 high, the center outlet is for fuel to the carb.
the outside outlet is to let gas vapor return to tank,
if the outside outlet is positioned other than at 12:00 high, after the vehicle sets for a long period of time, fuel can be syphoned out of the carb and sent back to fuel tank.
when you next try to start the vehicle, you will have to pump fuel back into the carb, this may take a bit of cranking on the starter to get the vehicle running.
however, after short periods of non run time, the vehicle will start right up as fuel has not had time to syphon out of carb back to the tank.
this may not be your problem, but you need to insure you have the fuel filter properly onientated.
if it does not fix your problem, (cold engine) set carb choke with one push of fuel pedal, then check carb to be sure the choke closed, if the butterfly did not close properly, this can make the vehicle hard to start. If choke is working properly, you might try a full tuneup and timing set.
driving these new vehicles with fuel injection that always start right up,
have made us tend to forget the good old days of carbs and choke settings.