I bought a set of carbs to put on my 1994 cbr 600 f2 and I pulled the bowls off and the jets out to clean them and discovered that the jets that were on the old carb said 122 and the jets on the new carbs said 135rd. Does anyone know if this is an aftermarket jet. Hopefully it is. Hit me up big time.

 

My 1990 1000F has a stock 122 main. According to my Haynes manual, the 87-89 600 used a 105 main and the 90 used a 110.

 

Your old carbs have a Dynojet jet kit in them. 122 is the "standard" jet size for them. The other dead giveaways will be that the needles in the slides will have adjustable clips, and one of the two vacuum holes in the slides will be glued closed.

Your new carbs have the stock main jets at least. If you want to keep your dynojetted carb jets, I've been looking for a set of stock main jets, needles, and slide springs, to put my carbs back to stock. I'll happily take them off your hands.