Found that there is a high idle when starting eventually lowering automatically when warm, this eliminates the trigger lock for starting. Don't know if this feature is on all 460 saws, I don't think so. The picture of the carb where you sent me shows splined jet screws.try the site below
click here for the husky parts site for the 460
you might pick out the parts from the pix.
just watch the part numbers to make sure they match your model run.
any idea how old the used saw is by date?
you might ring them and also ask where it was purchased from to get a hint of it was from a box store or dealer.