I'm having a progressivley worse issue with misfires on my '05 R1200ST.,which now has about 54K miles on it. What's happening is that when accellerating, the engine seems to cut out for a few seconds, then catches again. It originally happened at high revs but is now common at low and midrange. The engine is smooth and steady at all cruise speeds, but the gas mileage is off a lot. Not sure if it's related but I was using some high performance European plugs in the bike and they gave out rather early. The engine was difficult to start and it seemed like only one cylinder was working. Changing the plugs helped and I also changed the fuel filter at that time as well and it ran normally except for a much increased frequency of these misfires. I read where someone had similar issues that ended up being related to corrosion at the Throttle Position Sensors connectors, but can find no reference to such sensors in the BMW service manual. I have a GS911 and if shows there are no registered faults. At this point I'm not sure what system to check - ignition - fuel injection - engine sensors - so I'd appreciate any suggestions or recommendations from anyone that might have encountered similar issues.