My first project (550 LTD?)

If you clean the inside of the MC, does it look perfectly clean and polished inside? If so, the old piston and seals should work as long as the rubber is not torn up.

If there are rough spots inside (you can see them with a light shining in from the other end), then the piston will need new rubber to seal, but even then it may not if the pits are too bad or in the wrong spot. In that case you would want a new MC anyway.

Usually, as long as the donor bike has a single caliper, the MC will work on another bike that has a single caliper. You may have to get a new/custom line made, but you would likely want to do that anyway. Get a steel braided line.

On my 550's with rear disk, the rebuild kits have disappeared. But I went to a Ninja 250 rear master, and it works perfectly. I just had to make a couple spacers and a shaft adapter to connect it. But the feel is the same as a stock gpz 550 master.

You might be able to use the piston assy or rubber parts from the 1978 KZ650-B2 (43020-1026). I have the 650-CSR & from comparing photos, the Fr Br mc pistons look very similar. If it doesn't swap over (different length for example), the rubber parts may work. You could compare yours to the photo at Z1Enterprises.com.

Attached is a picture of the old piston compared to the one I ordered. The piston is slightly larger, and the rubber seals may be too loose to fit my piston. Time to search for a Ninja 250s MC, it is always good to have the 1978 KZ650-B2 (43020-1026) alternative that Martin mentioned.



Another question, where does this 12v reserve device go?

Part #43020-1023 is for a dual disk (KZ1100) --- the piston bore is larger.

Does the Ninja mc have a mirror orifice?

No eBay APP ID and/or Cert ID defined in Kunena configurationThis is the MC I am looking to get as a replacement below. There looks like there is an orifice for the a mirror to be placed. Do you guys think this will work?

Does anyone know where the 12v reserve lighting device goes on the bike?

TS wrote: Does anyone know where the 12v reserve lighting device goes on the bike?

Am uncertain, but would look for a connector from the main electrical harness that's located underneath the fuel tank.

Good Fortune!

No eBay APP ID and/or Cert ID defined in Kunena configuration

TS wrote: This is the MC I am looking to get as a replacement below. There looks like there is an orifice for the a mirror to be placed. Do you guys think this will work?

One consideration would be whether the threads on the mirror stalk at hand are the same size as the threads in the replacement master cylinder.

And if the thread sizes are different, another mirror would be needed to fit the replacement master cylinder.

Good Fortune!

Hi Patton,

The 12v reserve is already connected to the harness, I just cannot figure out where it was mounted.



I am not too concerned with the mirror, my state only requires one on the left side.

Would look for an attachment location just above the lower grommet under the right-hand side-cover.








These pics are from the KZ550 service manuals downloadable via the links in the signature of KZr member loudhvx.

home.comcast.net/~loudgpz/GPZweb/index.html#home

home.comcast.net/~loudgpz/GPZweb/Mnls/Mnls.html

Good Fortune!

On my 1980 kz550 ltd. the reserve lighting unit is located under the fuel tank and sits above the coils and frame tube using the front two mounting bolts that the coils are mounted with. If you hold the unit in position above the coil mount brackets you will see the hole centres match the reserve lighting device bracket.
Hope this makes sense.

No eBay APP ID and/or Cert ID defined in Kunena configurationNo eBay APP ID and/or Cert ID defined in Kunena configurationI had the same issue with finding a MC rebuild kit so i ended up buying this unit new from ebay, works a treat although I have fitted flatter bars to mine.