needle or main jet
 

If temps are dropping you are suppose to put in a bigger main jet ..
Is there any difference between that and just raising the needle?? Or is it just a different way of getting to the same place??

Needle has no effect on w.o.t. perf. You want to change the main which will influence perf from part throttle up then adjust the air screw clockwise to richen the pilot circuit for low speed. Fattening up for slippery conditions will enable a flater torque curve as well

so if you are in tight woods and not going WOT you could get away with just the needle, just don't get rev happy ... but to be safe go with the main jet if you got it

Correct. Most bikes are jetted on the rich side so you have some latitude before it melts down. Last week on a cold day I could'nt make it up a hill climb that would of normally not been a problem. Turns out the increased air density, from the cool air, and the to small 160 main, which I'd forgoton to change from the 100.f summer setup were conspiring to rob peak power. Bumped it up to a 172 and no problem making that hill.Think of your main like the water supply regulater at your house. OK for showering but not great with dealing with that house fire.