Hello all, first time poster. Just bought this bike a few days ago it’s an 08 drz 400sm and am starting to notice it has a strange backfire at idle. I understand a little bit at decel might be normal, but at idle too? It appears to have been jetted already, judging by the fact it has a jd jetting sticker on the bike itself. I know that it’s not an exact indicator it has but it could be. Has an FMF exhaust, it looks like a full system rather then a slip on but not entirely sure. A buddy recommended I mess with the air and fuel screw, haven’t done that yet. Just wanted to see if there was any other tips I should try.