NICE!! The throttle valve or slide has just one phillips head screw (on the shaft) and a nylon type washer next to it.
Inside the top half of the carb there are 2 tiny phillips head screws in the throttle valve/slide itself, they hold the jet needle. Don't strip those puppies, get a really good screwdriver! before you dive in.
Good luck!! Sounds like your running well and sometimes it's better to leave things well enough alone, before you create 3 other problems.......
All our government does is distract us while they steal from us, misspend our tax $ and ruin our country