Master Cylinder Questions

[YamadudeXS650C]

Last night I had a bit of a struggle with getting the circlip installed, so I closed down the shop and had a beer. Three beers, actually.
This morning, I made a modification to my internal circlip pliers in order to get down inside there more easily, and this time used the red grease instead of brake fluid on the piston.
It went in MUCH more easily, and the circlip went in more easily.
For this reason alone, I'll use the red paste from now on.
Even the dust boot went on well.
I use two 90 degree circlip pliers to work the dust boot onto the piston:

 

[YamadudeXS650C]

Completed the RD master cylinder. Initial bench testing suggests that the inexpensive rebuild kit is functional, yet we'll see for sure in the spring when I'm able to wheel it out of the house.
Also working on three of the XS's this past week, rotating from one to the next while awaiting parts, I've been impressed with the degree of similarities in construction and parts of these Yamahas. Perhaps I shouldn't be surprised; the RDs and XSs were probably constructed right next to each other, especially the '75s.

 

[Paul Sutton]

Is that master cylinder on the wrong way??

Edit: Just joking with you. Nice job!!

 

[MaxPete]

That looks nice and tidy Dude - can’t wait to hear that RD make some ring-dingy smoke!

 

[YamadudeXS650C]

Is that master cylinder on the wrong way??

It isnt actually on anything but a spare Euro handlebar, on the workbench. slipped it on the bar so the it wouldnt fall over while photographing it.

 

[robinc]

Looks good Dude. Looks like you repainted that RD MC. What paint(s) did you use?

 

[59Tebo]

 

[59Tebo]

'Dude,
I've seen worse. I have worse. Unfortunately, this one will require complete replacement. This is what happens when the Xs650 is used to hold up a shed for 10 years... It's all good, though. I'll be updating the whole bike anyway, so very little will remain stock when completed.

 

[MaxPete]

View attachment 111419

Oh dear me Tebo.....

 

[Paul Sutton]

Dude, will be nice to see the 350 running. I had a 250B for 5 years and it was great, but a 350 would have been much better. Make sure you always carry a spare set of spark plugs and spanner because you never know when they will give out due to fouling.

 

[YamadudeXS650C]

Dude, will be nice to see the 350 running. I had a 250B for 5 years and it was great, but a 350 would have been much better. Make sure you always carry a spare set of spark plugs and spanner because you never know when they will give out due to fouling.

Thanks, Paul.
I've read about the fouling plugs. Wish this bike had what my '75 F11 has, two threaded spark plug carriers under the seat.

 

[YamadudeXS650C]

View attachment 111419

Thats what my RD MC looked like. And it cleaned up quite nicely.

 

[YamadudeXS650C]

Is that master cylinder on the wrong way??

Edit: Just joking with you. Nice job!!

I didnt recognize my own brand of humor.

 

[YamadudeXS650C]

Looks good Dude. Looks like you repainted that RD MC. What paint(s) did you use?

Thanks Robin,
Since it was just a tiny, one-off job, and I was working inside the house in the winter workshop, I put two old shirts in front of the room air filter as pre-filters, and sprayed it right in front of it with rattle can Duplicolor gas and oil resistant Engine Enamel, then put it in front of one of my electric space heaters for awhile. "Oven cured".

 

[willis]

YamaDude, reviving an old thread but I am in the process of refurbing my 75 xs brake system. I am having issues finding a reasonable master cylinder rebuild kit, and your pictures at the beginning of this thread describe my exact dilemma. My master piston is the same as yours but cannot find any kits that resemble what came out of it. Did the replacement piston work out ok? Mine isn't in terrible shape but I definitely want to replace the rubber bits. Some of the replacement kits are listed at $80, and I'm not even sure they won't be different than the $20 kits I see on ebay like the one you used.

 

[YamadudeXS650C]

YamaDude, reviving an old thread but I am in the process of refurbing my 75 xs brake system. I am having issues finding a reasonable master cylinder rebuild kit, and your pictures at the beginning of this thread describe my exact dilemma. My master piston is the same as yours but cannot find any kits that resemble what came out of it. Did the replacement piston work out ok? Mine isn't in terrible shape but I definitely want to replace the rubber bits. Some of the replacement kits are listed at $80, and I'm not even sure they won't be different than the $20 kits I see on ebay like the one you used.
View attachment 135851

Willis,
The kit I got from Niche Cycle Supply,
http://www.nichecycle.com/ncs/categories/carburetor/mikuni-parts-by-category.html
did work OK for me. They sell on EBay, too.
However, that product was back in 12/17. They might be sourcing a different product these days.

Dude