Before I started diving into it, I thought I would bounce this off the experts... I picked up a 2008 KTM 990 Adventure S recently and have hit reserve twice thus far. Both times, the bike seemed to be starving for fuel while the reserve light was on. <o> </o> For instance, it would hesitate under acceleration, especially above 5,000 RPM, and pop noticeably while decelerating. My KTM 525 does the same thing just as I need to switch the petcock over to reserve. <o> </o> To me, this suggests that either the tanks are not vented properly or fuel isnt getting from the right tank fast enough even though both petcocks are open. If it were the fuel filter, I would expect fuel starvation regardless of fuel level. If it is tank venting problem, I would expect starvation to get progressly worse as fuel level in the tanks dropped due to the greater air volume. <o> </o> When I opened the gas caps at the gas station, I didnt hear any in-rush of air, but there was a noisy diesel truck idling nearby so I may have just missed it. After refueling, the bike again ran the same as it did before hitting reserve (i.e., no hesitation while accelerating, no popping on decal). <o> </o> This bike has the canister, SAS and servo controlled butterflies removed. It has Akros and Im told the Akro map loaded; however, I dont know which particular Akro is loaded.