2015 Triumph T100 Boneville Overheating/idle Issues

I picked up my 2015 Triumph Bonneville T100 a few weeks ago. It only has about 1,300 miles, so it’s still basically new mechanically, but it’s spent most of its life sitting. The previous owner told me he hadn’t ridden it in a long time.


When I took it for a short test ride (about ¼ mile), it ran perfectly. I then rode it an hour and a half home with no issues.


The second time I started it up, things changed. It began having idle issues, it would die every time I came to a stop. I tried adjusting the idle knob, but now it overheats badly after riding for a while. I’m pretty sure it’s running too lean, but no matter how I adjust the idle knob, I can’t get it to stop overheating or idle consistently.


When the engine is cold, it idles fine. But once it warms up and starts getting hot, the idle issues come right back.


Here’s what I’ve done so far trying to get it running smooth again:

• Changed oil and oil filter
  
  
• Replaced in-tank fuel filter
  
  
• Changed brake fluid and brake pads
  
  
• Cleaned and lubed the chain
  
  
• Replaced spark plugs
  

Everything is stock, no mods, and the bike is EFI and air-cooled.


Unrelated, but my speed sensor went out around the same time, it likely burned out from the overheating.


At this point I’m pretty frustrated and running out of ideas. Does this sound like a fuel delivery issue, bad sensor, or something else? What would you check next to get it running smoothly again?