Bonneville America Forums Forums Technical Forums Performance Mods leaving tomorrow, need quick help

hello all,
i know this has been talked about before but maybe someone can help me with my setup? got an 02 ba and just had the airbox removed kn filters epco pipes put on. the carbs got thruxton needles with one shim, 42 pilot 140 main. i left venice, ca on a trip up to bend oregon (sea level to 3500 ft) and everything was good till i got to higher elevation. it started to pop on decel and thought i needed to lean the fuel screw so turned it in and it got worse. went out to 3.5 and it got better. ok. left oregon up to vancouver b.c. (sea level) and turned it back to 3 out. got worse. backd it out a .5 turn and it got better. compression is a little low on one cylinder so i know the popping won't go away completely but the adjustments i've been making seem backwards to me. any help? going back to venice tomorrow and want a nice ride.