They don't need a dyno jet kit.
Been there, done that, had to change back to OEM for it to run right again.
Ok thanks I'll forget that then
Wasn't just on a whim, it was done properly at a Dyno Tuning place, but the bike just didn't feel great at all, so took it back and he put OEM jets in and all was fine again after that.
These bikes run rich with petrol as the norm anyway, so what they actually like is a bit more air which is why the K&N air filter is a simple but very effective mod to do.
Don't expect miracles or bundles of extra BHP, but what you will get is a much sharper throttle response and a better general all round feel to the bike.