warming up does many things
lets oil and coolant circulate in the dry areas
warms up the engine and oil close to operating temperature before applying heavy power demands
eliminates low end bog
elongates engine life by NOT running a cold engine
all engines operate best at a certain temperature range
as for the maroon who warms up his bike forever, thats stupid idea
you should never let a bike sit on idle more than 10 min.
though its an exception if you live in really really cold areas
running the bike with choke on is a bad idea too
i forgot the reason why though
voted for 5+ min. to take into account cold weather
but i usually set off when engine reaches MINIMUM 120F (at least on my 636)
250 - as close to 2k on idle, choke off, stock carb settings