If you are having spark issues on your Yamaha FZ600 then the ignition coils could be the culprit
Yamaha YZ 250 (1988-1995)
93332-00067 or 93332-00078
This is a high spec coil and you'll no longer need to run a resistor in the system to use this coil
Yamaha LC 50 Bop (1980)
Black Rear Shock Absorbers: Yamaha XS650 XS 650 (1975-1983) Yamaha YZF600 If you are having sparkBrand new set of black rear shock absorbers to fit: Yamaha XS 650 (1975 1981). Yamaha XS 650 S Special (1978 1983). This set of rear shocks is designed to replace the original factory shocks on a Yamaha XS650 for the years shown above. The models are B, C, D, E, F, G, H, SE, SF, SG, SH SJ, SK. It has 325mm pin pin mounting points and a 40mm shroud. The top pin is 14mm, the bottom is 10mm (You may need to change these to the required sizes spare bush's