New to the KZ250 need help

when i got the bike it was running really rough. I have cleaned the carb, cleaned the fuel filter, changed the plug, and it is still running rough. i was trying to figure out how to check the time. can anyone give me a brief walk thru on checking and adjusting the timing. Any other suggestions would be helpful.

The fastest way to eliminate a multitude of guessing with an unknown engine is to perform a compression test. I'd start here before worrying about timing.