Regarding the jetting, there are a lot of variables as Half-Breeder suggests, including altitude. You really have two courses of action as far as I am concerned. One- buy a couple of extra jets in the same size range, and experiment with them until you find the right mixture, or do what I do- purchase a pin vise (precision or jeweller's drill) and a set of numbered (precision) drill bits to go with it. I drill my own jets on a regular basis, and once you've got the idea, it's pretty painless.
It's not half as expensive as it sounds. You can pick up a pin vise and a set of numbered bits (#61-#80) online for under $20.
With a warm engine and a clean plug do a long pass at WOT. Shut it down immediately and carefully (HOT) remove the plug. Look at the ceramic insulator surrounding the plug tip. Bone white or very light, you're too lean. Drain carb and pull the jet. Use the shank end of the drill bits to determine current jet size. Select the next larger bit, and drill the jet. Reinstall everything, and test again.
You want a good tan to chocolate brown on the plug insulator. If it's really dark or even black, you've gone too far, but alas, you're not dead. You can solder the jet orifice closed with a plumber's torch and redrill a smaller orifice.
When testing and drilling, go up only one drill size at a time. I have soldered a few and started over, but it's a process you're better off skipping.
