1990 ZX-750 clutch won't disengage. Little to no pressure when pulling on clutch handle. I flushed the lines, fluid flows out of bleeder in the slave cylinder with no bubbles. I'm thinking bad master cylinder need rebuilt?

 

Do the slave while you are at it.

 

We are talking about the slave cylinder not being retracted correct? As in, it is stuck or the master gasket is leaking. So pull the slave as MaverickAus mentioned, make sure it is free moving. Verify that the diaphram on the clutch master is in good conditon and that setup is moving freely. Re-bleed

The master cylinder is normally the prone issue that needs to be rebuilt since hygroscopic fluids really suck in the moisture and contaminates/sticks other components. I have had a stuck input shaft from the slave cylinder before however. which were my clutch issues.

I still have my new back then '90 hoover tube zx7 H2. A chunky machine for sure. Congrats.

 

Got a pump and sucked fluid through the clutch lines about 15 times. Shifts like a dream now. Got both rebuild kits for when the seals do break down. Bleeding is a bitch. Thanks for the replies gents.

 

Another way (which I haven't personally tried but others swear by it) it to get a syringe and clear tube and push it up from the bottom. In other words loosen the bleed nipple put the tube on it and fill using the syringe.