How to define Weight of a PART ????????

Hi All,

How can i define Weigh of a part.

I have an assembly in which i need to put a motor.
i have dummy model of a motor which gives just overall look ofmotor.

now i want to add weight of this motor in BOM.
I have the weight of this motor.
The dummy motor's mass prop not shows the actual weight.

Thanks,

BirenSolidworksAssemblies