I've got a warrior 350 jetted with a pipe. I never need to use the choke to start it, and it always starts right away and runs fine. Is it unusual to be able to start a 4 stroke when it is cold without the choke on?
It isn't weird at all. It just means you are getting the perfect air fuel ratio to start when cold, without opening the enrichener circuit.
If it aint broke, don't fix it. 8)