You do not need a gasket "kit".
You should not need a float bowl gasket or O ring. but if you already
removed it you can get those separately.
If you have 1978 carbs the idle jets just pull straight out as you twist.
Make sure to hold them up to the light to make sure you can see light through them. Clean with a #10 or .010 thousandths electric guitar string.
You can buy those separately, You do not have to buy a whole set.
On a Roadstar Adventure.