The safety agency says it will look into what caused the fires. Investigations can lead to recalls.
The motorcycles are made by Bombardier Recreational Products Inc. of Canada. Messages were left seeking comment from the company.
The Morgantown police, in a July 23 complaint to NHTSA, said an officer was riding the Spyder on a city street and felt heat rising from beneath the motorcycle. The officer saw flames coming from the engine and moved it to the side of the road. "Within seconds the vehicle was fully engulfed and flames caught a yard and two nearby trees on fire," the complaint said.
The Fire Department and a city mechanic determined that the fuel system was the source of the blaze, the complaint said.
No one was injured in either fire, but the police motorcycle was a total loss.
The three recalls happened in 2012 and 2013, and all involved the risk of fires. Last year, the company recalled about 8,200 Spyders because brake fluid leaks could cause fires. In 2012 it recalled about 34,000 because fuel vapors could leak due to an ill-fitting gas cap. It also recalled 9,600 because fuel vapors could exit a vent hose in the engine compartment.