Troubleshooting stumble at idle in gear

NGK 7 spark plug is too cold, should be a 5.
This doesn't sound like a carb/fuel problem...if you are just getting a momentary misfire.
Sounds like ign.
- plugs
- coil
- wires
- leaking spark plug boots
- dist p/up air gap, too big or too small
- worn dist shaft causing above
- if vac adv has been hooked up & dist has a lot of mileage, p/up wires can break from flexing causing no spark
- electrical connections in the ign system &/or low voltage to the ign. Try a jumper direct