To change the front lights on a Yamaha FZ600, first, ensure the motorcycle is turned off and the key is removed. Remove the headlight assembly by unscrewing any fasteners and disconnecting the wiring harness. Replace the old bulb with a new one, ensuring not to touch the glass with your fingers, and then reassemble the headlight by reconnecting the wiring and securing it back in place. Finally, test the lights to ensure they are functioning correctly.
Found a 1986 Yamaha FZ600 for sale. Going for $800.
Some of the Yamaha motorcycles that came out in 1986 are: FJ1200, FZ600, FZ750, XJ600, XJ700, XS400 and YX600. The YX600, also knows as the Radian, was the most affordable at that time.
The FZ600's have an air cooled engine, and I think the Fz's are the only one's at the time that came with an oil cooler.
go to yamahaclub.com, there are plenty of experts on there that know everything about the older fz's. I believe the gapping is supposed to be.... from .7mm to .8mm. I would suggest NGK plugs too, made for performance!
buy a manual, they usually will have them in depth in the back somewhere (at Least Haynes & CLymers do.). they usually only run for about $20 and are well worth it, giving lots of other helpful stuff too.