Yes, but now that its colder out your LEAN and it dont matter if its stock or not, cold = lean no matter what, so you will have to richen them up. Throw in a pair of 27.5 pilots and try it. For a few dollars and 10 mins of your time, give it a shot. Just make sure you adjust your air screws and idles accordingly. No need to take it to the dealer and pay them 200 to change your pilots out and what not, with such a simple carb issue.
Sounds like your needles are lean now also that its cold.
Also make SURE your carbs are in sync to one an other and the choke tube is in place also.
Here is a good link for your Mikuni"s 26's Very good read man everything you want to know and all your questions to how and why are answered here.` http://www.dfn.com/benkaren/jetfaq.html
IMO you should make sure your mains arnt lean now that its cold aether. So do a Proper plug chop to the "T" then you will know. Dont miss a step or its pointless. http://www.dfn.com/benkaren/plugchop.html
Also IMO you should check ALL electrical also, my coil went out a few years ago and i didn't know. I chased the jetting around for 2 weeks and was so pissed off. Went up and down the jetting a couple times, then finally tested all my electrical and the coil worked but had a weak spark. Sometimes electrical stuff one day works proper then the next something goes...just how it is. Heres a good link to ALL your electrical know how and questions and what to do for banshees. http://www.bansheehq.com/index.php?option=com_content&task=view&id=12&Itemid=28
All good links to bookmark for now and later.
Also if you don't have a clymers manual, pick one up and E-bay for $30 Shipped. Very good to have also and everybody should have one on hand.
Good luck