1983 KZ550 M1 needle jet orientation

My son and I are rebuilding the carbs on his 550. We went to put the needle jets in and neither one of us knows which they they are supposed go. They have 1/2 cut out and we would like to find out if the cut-out section faces the filter side or the engine side. Any help would be greatly appreciated. Thanks

 I finally found it. The open side goes towards the engine.