A stock Honda does have a rev limiter somewhere in the 14k ballpark. It’s not something you’ll hit during a race as you lose power around 12,400 with a 99 cylinder and 12, 800 with a 01 cylinder. These are where you should be shifting.
You won’t be able to dump the clutch without stalling or bogging the motor. During a start (after the motor is warmed up), a lot of people will hold the brake, mash the gas (let the rev limiter do it’s thing), let the clutch grab a little (you’ll feel the kart want to move) and aggressively let go of the clutch and brake to get a good launch. Personally, I don’t mash the gas (to the rev limit) but I am in the 11k or so range when I go to launch at a start.
If the motor isn’t warm and you’re just pulling out from the pits than you should be much less aggressive. The Honda’s are very very tough but beating on them before they are ready isn’t a good idea.