350x Jetting

[Kawboyz beware]

I recently put a exhaust on my bike I was wondering what What type of Carb do I have? on the carb in the casting there is a QA and below it stamped into the carb is the #s 05AAYBT
Can someone tell me how these #s break down? The Bike Currently has the stock 138 main and has the stock pilot and needle. I want to order the right main jet. and do you think I would need to change the needle or Pilot?

[dork]

not sure on the numbers, probably a production date. but you have the stock carb. for 85 the model is a keihin QAO5A, 86 is a keihin QA10A. both are 31mm. stock jets are 138 main, 45 pilot, 3rd clip on the needle. try a few sizes larger on the main to start. if it pops on decel alot try turning the fuel screw out. if you end up more than 2.5-3 turns out then go one size up on the pilot.