Yamaha XZ550RJ 1982 Owner's Manual page 157

Carburetor adjustment
The carburetor is a vital part of the engine
and requires very sophisticated adjustment.
Most adjustments should be left to a Yamaha
dealer who has the professional knowledge
and experience to dtr so. However, the
following point may be serviced by the owner
as part of his usual maintenance routine.
Idling speed adjustment
-145-
1. Start the engine and warm it up for a
few minutes (normally, 1 or 2 minutes)
at approximately 1,000 to 2,000 r / min
occasionally raising to 4,000 to 5,000
r/min for a few seconds.
When the engine responds quickly, the
warm up is complete.