looks like you may have a 'regurator' ( a voltage regulator?), pictured just above the 'rectifier'.
Is there some component on the bike that has a single terminal and appears similar to the one you purchased? (the ground 'terminal' would be the metal body of the device itself) The wire color connected would be.. L? wtf color begins with L?
btw.. why did you order a rectifier? Is the old one broken or is it missing.. and if it's missing, have you found the wire terminals (white and red) that should be connected to it? If it's not missing, what does it look like?
You can test a rectifier with a multimeter. Basically, resistance in one direction is high, and much lower in the other. Use the 'ohms' setting on the meter and hook it up..
Honda made rectifiers with 2, 3, and 4 wire connections.. I dunno about Yamaha.. If this diagram is correct for your bike, it looks to me like you did not buy a rectifier.