Help Needed on Master Cylinder Choice

[Guest]

I need to purchase a front master cylinder for my 550 which has twin rotors, I have come across this new item on EBAY Item No. 120694922080.

It says in the description it suits a double caliper brake system, but it also says it is 14mm piston & bore. The usual standard for twin rotors is to use the 5/8" (16mm) bore master cylinder.

Could someone that is in the know have a look at the item and give me some advice on whether it will work on my bike or not. Presently I have a single rotor master cylinder on my 550 which is I believe 14mm and is a bit spongy. Will this master cyl be any better, it's a good price and new, but wasted money if there is no improvement.

Thanks for any help given.

[Nessism]

Don,
A 14mm bore master on a dual disc GS will have a more spongy lever feel than a 5/8" master. Simple physics. The larger master will take more hand effort though so there are trade offs involved.

[waterman]

Don
I have the master cylinder from the same Kawasaki calipers that you have. When I get back home, I will check to see if the size is listed on them and report back.

I haven't had a chance to run bike yet so I can't say how they feel. I assume the master cylinder will work okay with these calipers. If I get off my rear and get some lines made/purchased and it stops snowing here, I will be able to give a better account.

[waterman]

I did a little eBay checking and I believe that stock size for those calipers is 5/8 inch like Mr Ness suggests. So I would think the one you are looking at will not be what you are looking for.

Here is the link where I found a clear picture with the size shown.

http://cgi.ebay.com/ebaymotors/Front-Brake-Master-Cylinder-Kawasaki-ZX600-Ninja-600R-_W0QQcmdZViewItemQQhashZitem5881cf0204QQitemZ380134949380QQptZMotorcyclesQ5fPartsQ5fAccessories

[Baatfam]

Magura...16mm...a little pricey, but good quality...

http://www.schnitzracingstore.com/ca...showprevnext=1

[makenzie71]

How important is it to you that it look like original equipment?

This is what I would get: http://cgi.ebay.com/ebaymotors/02-GS...Q5fAccessories

If money weren't an object: http://cgi.ebay.com/ebaymotors/BERIN...Q5fAccessories

Or, if money were the ultimate object, I'd just go HERE and ask. I bet you could score one for free.

[Nessism]

Magura...13mm...a little pricey, but good quality...

http://www.schnitzracingstore.com/ca...showprevnext=1

Why would anyone with dual discs want a 13mm master?

[waterman]

Why would anyone with dual discs want a 13mm master?

Hit the "next" button and you get a 16mm master for dual disks.

[Baatfam]

Hit the "next" button and you get a 16mm master for dual disks.

Thanks...that's the one I wanted... 16mm=5/8" duh!!

I edit the other post.

[Nessism]

16mm is the ticket.

That Bandit master doesn't have a mirror lug. Some of the GS masters have the threaded lug on the removable bar clamp piece so you could possibly use your old clamp (assuming the lug is built in) along with the newer master.

Partsnmore.com has some masters for reasonable prices. Check in the Yamaha section.

[makenzie71]

That Bandit master doesn't have a mirror lug. Some of the GS masters have the threaded lug on the removable bar clamp piece so you could possibly use your old clamp (assuming the lug is built in) along with the newer master.

Then I accidentally posted an S master...the naked ones have the mirror lug. So do SV1000 masters. First-gen Hayabusa masters do as well...I ran those on everything for a long time. Now I run radial Yamaha masters when I can and I have a clamp that dedicated mirror lug.

[Suzuki_Don]

Thanks for the replies

Thanks for the replies. It has been a challenge for me to find a 16mm master with the mirror mount, a lot of the masters suggested by different members on this post are fine but do not have the mirror mount. I have noticed though that the later model Suzukis particularly have that half clamp with a threaded section on top for the mirror to screw in as suggested by some on here.

Personally I would like to keep the bike original with the 16mm master with the round screw-on cap from about '78 to '79. But these seem as rare as hen's teeth. Failing that I would like to buy a brand new master so I know it will work perfectly without the need to be rebuilt. I rebuilt the 14mm stock master that is on my bike now, but i think the fluid is leaking past the piston, seals, etc.

The other night I thought the system had air in it so I bled both calipers. No air bubbles evidenced themselves. So I pulled the brake lever in and cable tied it to the handle bar. The following morning the lever was loose inside the cable tie and after removing it I pumped up the lever three or four times and I then got the pressure back in the front master.

So I am thinking the bore of the master might be worn and fluid is passing past the seals. The piston and seals are new factory parts so I know it's not that. Having said all this the front master has never caused a problem with loss of pressure when riding the bike on the road. It pulls up fine just feels spongy and the single rotor with the same caliper (only a single though) on my VX has a much better and firm feel to it.

Any other opinions greatly appreciated, or even if anyone has a master cylinder they would like to sell me or if anyone can point me to a master cylinder on Ebay that they come across that would be appreciated as well. There is a brand new GS1200 master cylinder here in OZ for sale for $150 but it is minus the brake lever which would cost me another $100 or more new from Suzuki here in OZ, it is a Nissin Master. Maybe I should just bite the bullet and pay up or maybe search the bike wrecking yards over here.

[Nessism]

Don,

I have one of those master cylinder clamps with the mirror lug built in if you want it. Could measure the center to center hole distance if interested so you can figure out if it will match some other master.

[Suzuki_Don]

Don,

I have one of those master cylinder clamps with the mirror lug built in if you want it. Could measure the center to center hole distance if interested so you can figure out if it will match some other master.

Thanks Ed for the offer. I will keep it in mind. I have just purchased off EBAY a master off an '88 ZX10 which should be 16mm as it has twin rotors. But it has the rectangle lid that screws down with phillips screws. I have asked Tarbash to look through his stuff to see if he has an original round lid master that is the 5/8" one. I plan to put the ZX10 master on when it arrives but would change over to the round lid type if I can find one eventually. Will probably need to make up new brake lines as the ones on the bike now are just long enough and might not reach the new master sufficiently. But that's no problem.

Thanks again Ed.

[Suzuki_Don]

This is the ZX10 Kawasaki master cykinder that I purchased off EBAY. It should work OK. Guess I should rebuild it with new seals at least before I install it.





88 KAWASAKI ZX10 FRONT BRAKE MASTER CYLINDER



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