UNLIKE MOST MOTORCYCLES, WHERE A SIGHT GLASS IS USED TO DETERMINE ENGINE OIL LEVEL, THE SUBJECT, AIR-COOLED, MOTORCYCLES ARE BUILT BY BMW WITH A POLYMER (PLASTIC) SIGHT GLASS THAT, IN SOME INSTANCES, MELTS DUE TO HIGH ENGINE/OIL TEMPERATURE.THIS TYPICALLY OCCURS WHEN THE MOTORCYCLE IS OPERATED CONTRARY TO BMW'S OWNER MANUAL ADMONITION: WARNING:DO NOT KEEP THE ENGINE RUNNING WHILE THE MOTORCYCLE IS AT A STANDSTILL -- RISK OF OVERHEATING AND FIRE.EACH OF THE ALLEGED FIRES OCCURRED WHILE THE MOTORCYCLE WAS PARKED AND IDLING.ODI IS UNAWARE OF ANY STRUCTURE FIRES WHERE A MELTED SIGHT GLASS IS THE ROOT CAUSE.OF THE EIGHT KNOWN FIRES, ONE OCCURRED IN 2000, THREE IN 2004 AND AGAIN IN 2005, AND ONE IN FEBRUARY, 2007.THE SUBJECT VEHICLES DO NOT HAVE AN ELEVATED FIRE-RELATED INSURANCE CLAIMS HISTORY. BASED ON THE LOW INCIDENCE RATE, IT APPEARS BMW'S WARNING IS EFFECTIVE AND NO DEFECT TREND IS IDENTIFIED.FURTHER USE OF AGENCY RESOURCES APPEARS UNWARRANTED.THIS INVESTIGATION'S CLOSING DOES NOT CONSTITUTE A NHTSA FINDING THAT NO SAFETY-RELATED DEFECT EXISTS AND WE RESERVE THE RIGHT TO TAKE FURTHER ACTION IF WARRANTED.