On my '06 K1200S at about 29500 km, the fuel economy slowly reduced from 4.8L/100 km to 5.2L/100 km. I was on my way to BMW Motorrad for the 30,000 km service so I figured after the valve adjustments and service, the declining fuel economy would be corrected. However, on my 350 km ride home, the fuel economy continued to worsen. When I parked my bike at home, the fuel economy had reduced to 5.6L/100 km. I am baffled why, within a 1000 km, my fuel economy would go from 4.8L/100 km to 5.6L/100 km. Any ideas what could cause this drastic change in fuel economy? The bike sounds and performs as good as ever and I am not riding the bike more aggressively than normal. The weather has been between 33 and 38 Celsius where I have been riding. The air filter was not changed during the 30,000 km service and the valves did not need adjusting; they were within acceptable ranges. There were a ton of bugs on the bike. Could it be that the air filter is clogged? Any ideas would be appreciated. Thank-you.