Not sure what year but I believe Yamaha added daytime running lights to the front turn signals (and thus dual element bulbs). If the one you purchased is from a newer model, it will most likely have two extra wires that will not match up to anything on your 87 front turn signals. They should be the same color. Also, it’s not too hard to open up the speedo and light clusters and make sure they have working bulbs. There should be a link to the wiring diagrams in the tech section.