Typical things they want to know are if I think a bolt is tight enough, or if their chain is correctly adjusted, or if their jetting is right, or if the nail sticking out of their tire might mean trouble. But, see, with all my experience, I know better. You want to gob red Locktite on the threads and tighten to where it feels snug. Once dry, you'll need an impact wrench to remove that sucker. Proper carb jetting is an art.
Most carburetors have different jets and circuits for different throttle openings and flow speeds.
What they don't tell you, is that most of these circuits overlap. I like Jay's method of tuning carburetors. He changed his bike's pipe, changed its intake, bought all the jets that were available, and then diddled around with the carb and all his jets until the bike wouldn't idle and was a bear to start. He finally chucked the whole thing and bought a pre-jetted aftermarket carb from Jeff. Then again, Brad and I tuned Paul's bike at the Rubicon by removing the carb, leaning the main jet, leaning the pilot jet, lowering the needle valve, and bending the float tang up about 45 degrees.