Replace or repair

1980 kz650 ltd is bike in question. Master cylinder was showing signs of seeping(paint and corrosion at right controls), so i yanked it and dropped into ultrasonic for cleaning. Not sure if i should try and source a rebuild kit(z1 doesnt seem to have the correct one, but gonna call on mon) or just replace with a modern one(not sure which one is the correct one for that task) but looks like it might involve some kind of plug update for brake light switch. And suggestions,recommendations or actual part sources are greatly appreciated.

You might want to check the aluminum bore for corrosion pitting.  Even if you find a proper kit, if the bore is damaged, you are dead in the water.

Bikes with dual front discs use a 5/8" bore master.  And single disc bikes take 14mm masters.  eBay has tons of cheap replacement China masters that are serviceable.  Master cylinders are very simple devices.  Or, you can hunt down a late(er) model master from a low mileage bike.  My bike is running a master from a 650 Ninja (the rectangular version, with mirror lug.)  There are lots of options.

P1010741 by nessism , on Flickr

Thank you for the reply and suggestions.Definately will check the bore for pitting. Any chance you can narrow the age range on a substitute like yours. Your Pic looks like that style would work on mine as well. A ballpark year would help narrow the wide array of design and function. 

rebreath wrote:

Thank you for the reply and suggestions.Definately will check the bore for pitting. Any chance you can narrow the age range on a substitute like yours. Your Pic looks like that style would work on mine as well. A ballpark year would help narrow the wide array of design and function. 

I don't remember the year.  Search eBay for "650 ninja master" and "EX650 master" and you will find tons of them.  Just be sure to focus on the rectangular shape model.

So master is not pitted and appears serviceable. Figured while i was cleaning and replacing what needs replacing that i would service the caliper as well. Sadly the piston is pitted. What are my replacement options as i cant seem to find a new piston and the kits dont include that part. Might need a whole new caliper if i cant locate one. Thoughts or suggestions

Check with Brakecrafters. 

As always you folks are super helpful. Brakes completely rebuilt and converted to 5.1 fluid. No more paint corrosion or hydrophilic tendency. On to the next bit of upgrade now.......the headlight. What are my options for a headlight upgrade? Can i run an LED without crazy wiring changes? 

I've been happy with a quality H4 lense and bulb. Plus it doesn't upset the charging system balance. To be honest if you need more than that maybe you shouldn't ride at night.