Larry,
To figure out what jet you have you need to remove your float bowl, you can leave the carb attached to the intake.
1) Remove the screws and slide float bowl straight down, take care not to bump your float. If it's stuck a little tap with the back end of your screwdriver will suffice.
2) You will see your main jet between the two float halves. Use a stubby flat-head screwdriver and carefully remove jet. There is a brass washer that may or may not come with the jet, don't loose this. A rag on top of the engine case will prevent you from losing any dropped parts in the crevices of the motor.
3) Once your jet is out, you'll be able to see the stamped size on the face of your jet. If you're like me, reading glasses or a magnifier will help greatly.
Buy at least the next three larger sizes, i.e. 112.5,115,117,5 etc. Don't rely on what the owner's manual says your jet size is, someone(dealer, factory) may have switched it to meet a particular countries emmission standard.