I have a 01 Raptor with a White Bros. R4 slip on, K&N filter, and a jet kit. I just upped the mains so I could run without the air box lid. I am trying to get it tuned right before we head to Little Sahara this weekend. On my pipe you can run with or without the spark arrestor, how does this affect tuning?? I am runnnig 162.5/167.5 for main jets how does this sound? I am in Kansas, but I don't exactly know my elevation. I know we're pretty low.

I need to be running in the best condition I can, all my buddies have Banshee's.

I am also putting on a 12 tooth front sprocket, can I expect much gain from this??

 

The 12T sprocket will help in hill climbs etc. If you were climbing a hill in 2nd before you might be able to do it in 3rd now, thus getting up it quicker. As for the jetting you need to know the elevation where your going to be riding at. If where your at now is near the same as where your going then you should be ok.