I live at 5,000 feet and often ride up to 10,000 feet. It wasn't looking like the 250 would be the bike for those rides as it ran out of power at about 8,000 feet. I wasn't eager to get into messing with the stock carb because that can lead to a prolonged PITA. I didn't want to just throw in a bigger main jet and cross my fingers, I wanted a kit. Cruising eBay I came across this:http://www.ebay.com/itm/Kawasaki-KLR250-KLR-250cc-250-Custom-Jetting-Carburetor-Carb-Stage-1-3-Jet-Kit-/330728777671?pt=Motorcycles_Parts_Accessories&vxp=mtr&hash=item4d00f8a7c7
What impressed me immediately was how clear and comprehensive the instructions were. Following the instructions I had the carb back together in about an hour.
Last night I rode up a nearby 4x4 trail. Last time there I needed to use the choke just to keep the bike running. This time, no choke and all the power I needed. I found some trails that went up to 9500 feet and, again, no lack of power.
This mod really wakes the bike up and was 40 bucks well spent IMHO.