I have 2002 zx6r:

Just got my bike out of the shop. Got full 30K tune up and few repairs. I''ve found out that it has full Akroapovic(?) exhaust system and "jetted" for that pipe. What does the "jetted" mean?

Also, due to the exhaust/pipe being jetted, I have hard time starting it. The guy started it right away, but whenever I tried to start it it just turns and turns but no start. He said leave the choke closed since it''s closed unless it''s cold out. Any ideas on why it doesn''t want to start? And any help/suggestions? Thanks