GS1000 Guru's.... M/C question

[Rover]

Went on Part Shark to look for a M/C piston and cup set OEM.
for a 79 GS1000.They lump 78-79 together,but have two part numbers
The GS1000c is 59600-33810
The GS1000ec is 59600-47810
So there were two different master cylinders for those models?
News to me.Any body got pics?

[hampshirehog]

One will be for the single disc and the other for the twin disc. I'm not sure which way round though. But if you have the twin disc set up on your bike just get the one for the GS1000SN -it's the same as the one fitted on the other 79 twin disc bikes.

[salty_monk]

C is the single with 14mm piston
EC is the dual with 5/8" piston.

No I don't know why one is marked in metric & one in inches but they are...

[LarryC]

I just worked on my front brake(GS1000N). I bought parts from Z1. To make a long story short- u may have larger or smaller pistons in your caliper. I bought a set off ebay and the one I wanted had a smaller diameter. Bakes said he'd seen that in Kawasakis b4. Didn't say if this was a first in Suzi's for him but...

The MC for a dual disc brake will be of a larger size than that for a single. I moves more fluid- provides more pressure to suit. They look identical on the outside.