I'm really curious to do both the brake and clutch master on mine after working on my brother-in-law's CB750 Nighthawk. I was shocked at how much gunk was in his bore, even though we had flushed the master and the caliper thoroughly during the refurb. When I removed the master cylinder piston rod, there was a lot of black gunk even though the reservoir and lines were clean. Also, there's a TINY relief hole in there that that you need to be certain is clear.
I'm looking into master kits and will probably tackle it on my ST this fall. This is just a potential goo-alert in case you've never opened yours up.
I'm looking into master kits and will probably tackle it on my ST this fall. This is just a potential goo-alert in case you've never opened yours up.