We remove them after the engine has a couple of gallons thru it. I've noticed some run so rich they drown. After we remove them they are really pretty nice engines. The high speed only needs to remove the set screw. It will come off with the needle valve detent. Put the detent back on and go for it. The idle just needs the set screw removed and you're in business. If its new, run it with the limiters for a couple of gallons or so.
We had one that became very finicky until we removed them. Was great afterwards.
Edwin