As we all say check battery cable and see if there tight.
You might have a gas cap that isn't venting right.
Next time it stumbles open cap and see if that helps.
Most gas stations go threw so much gas that I would not think the station has bad gas especially if the station is new.
Check your plug wires see all is clean.
Not sure what a dealer could do for you cause the bike runs and till its broke you just never know. You can put to much gas in the bike.
35 different model bikes over the years. No Monkey in my garage.
Mpls,Mn. no orange in my county
Please add your city and state after the model of bike you have. Click user pc at top of page and then far left click edit signature. Thanks