1. Here's what came out of my carb. It appears to be a KLX needle kit! I hadn't expected this as I thought the bike was bone stock. When I purchased the bike two years ago (with ~1200mi on it) the dealer mentioned that they tuned the carb, but nothing about an aftermarket carb kit.
Too the well trained eye that Short Top Stem above the circlip on that mid-range needle suggests it was a DynoJet Kit.I also noticed this writing on the carb for the first time, and I can confirm that the main jet I removed was a 142 and the air/fuel mixture screw had been backed out 2.5 turns.
Both the needle & the taller headed main jet are probably stamped "DJ xxx". Use a magnifier.
A Properly installed KLX jet kit would have had 1mm thick brass spacer installed on Top of the circlip to prevent the needle from 'floating' up & down under the white plastic needle retainer. The DJ needle should have had 3 thin shims stacked on top to do the same.
The KLX needle has a taller Stem above the circlip grooves to retain its spacer. (ID# N1TB)
The DJ main jets are Richer size for size than Keihin main jets. The Keihin main jets have a stylized 'K' near the size #.
Your bike was possibly running richer than necessary with that previous jetting set-up, reducing fuel mileage and causing the exhaust to run cooler.