Just finished replacing my petcock on a '97 dyna. Bike always ran kinda rich so attempted to lean it out a bit adjusting the air/fuel mixture screw. Then I noticed the bike was popping when down shifting or decelerating ... so I thought I leaned it out too much. But then I noticed the bike sounded louder when I first started her up.

I just discovered the flange on the exhaust pipe to the cylinder was loose. As a matter of fact one nut was gone, and the other nut I simply removed by hand. Question is ... the stock nut was just a regular nut that had a wider edge on one side. Can I simply replace the missing nut with a regular LOCK nut?

Hoping this solves the noisier exhaust at startup (which only lasts a minute or so) and the popping problem.