Here is the best-practice procedure for installing the carburetors on the Honda GL1000. After reading and considering it, you'll understand the order in which these things must be done.

1. After installing the manifolds onto the carbs, rotate them 90 degrees. Keep the clamps loose. Put some adhesive on the manifold o-rings to keep them in place. Lightly grease them afterward.
2. Leave the aircut valve disconnected, but the hose attached to the #1 carburetor.
3. After laying a towel over the coolant passage pipes, slip the carb assembly in. Watch out for the #3 manifold catching on the tach cable.
4. Rotate the manifolds into their correct orientation but don't bolt them down and don't tighten their clamps.
5. Attach the aircut valve after lightly greasing its o-rings.
6. Connect all three cables.
7. Bolt down the manifolds.
8. Tighten the manifold clamps.
9. Sychronize the carb throttles (engine running)
10. Attach the chromed linkage guards.