Why would you need to adjust the RPM back to 1000'?
My IO550 just burbles into life and settles at 7-800 rpm.
Refer to:
http://www.lycoming.textron.com/supp...Operations.pdf
Page 32
4. The engine should be operated at engine speeds between 1000 and 1200 RPM after starting and during the initial warm-up period. Avoid prolonged closed-throttle, idle-engine speed operation (when possible). At engine speeds from 1000 to 1200 RPM, the spark plug core temperatures are hot enough to activate the lead scavenging agents contained in the fuel which retards the formation of the lead salt deposits on the spark plugs and exhaust valve stems. Avoid rapid engine-speed changes after start-up, and use only the power settings required to taxi.