I am having a problem adjusting flame on 2 of the 3 burners it will not adjust to a tight cone and the excess flame keeps triping heat censers I took apart and wire brushed everything inside burners can they go bad they are 17 years old.

Time to run a carbon monoxide test. You may have a bad heat exchanger or restricted flue. You may want to call a professional to have it tested. Never adjust gas pressure with out a manometer and never ever bypass a safety limit switch.