Blowing air through them would tell you much.
On syncing your carbs, if 2 and 3 exhausts are connected at the exhaust, you will have to look at the manual, Suzuki used this weird vacuum machine and on bikes where 2 and 3 are connected, the syncing requires that they bee a "11/2" ball lower that 1 and 4 carbs. This is due to the scavenging done by the exhaust. If they are each connected to 1 and 4, 1 and 2 then 2 and 4, then you sync in the normal all equal manner.
On syncing your carbs, if 2 and 3 exhausts are connected at the exhaust, you will have to look at the manual, Suzuki used this weird vacuum machine and on bikes where 2 and 3 are connected, the syncing requires that they bee a "11/2" ball lower that 1 and 4 carbs. This is due to the scavenging done by the exhaust. If they are each connected to 1 and 4, 1 and 2 then 2 and 4, then you sync in the normal all equal manner.