Suzuki master cylinder on a Yamaha?

[mharrington]

I am doing a street tracker-ish Yamaha XS650- the real challenge is my budget. I did buy the seat and fender from Gopherglass but the tail light is from a Kawasaki KLT 200 3 wheeler (just the right size). The front master cylinder leaks where the cup fits into the body. I have not seen a replacement seal for THIS area. I have a master cylinder from a 78GS750 Suzuki. The GS had dual front calipers and the 650 has single. I am asking for trouble due to fluid volume and psi differences?

The original XS650 master cylinder does not fit leveL on my non pull back handlebars ...so- I installed my spare XS1100 standard master cylinder on my 650....and this is the one that leaks.

The tail light is from a 1983 Kawaski KLT 200 3 wheeler I had laying around. Its the right size. The bracket for the light and plate are from metal laying around.


I ordered some small aftermarket turn indicators. I would like to re use these oem units but they stick out too far. My leg will easily "catch" them getting off and on the bike.



This is the extra master cylinder from an XS1100F. The fluid resevoir has a seal where it sets into the body. It leaks there-at the bottom. The XS650 master cylinder does not leak but is angled for the oem Special handlebars. I dont like the angle when mounted on the non pull pack bars. The 650 master cylinder looks similar to the 1100 but the only things that interchange are the lids. Resevoirs and seals are completely different.

[XS1100 Newbie]

Don't think you will have much brake with the larger bore.

[Schming]

What you could do after you put a new O-ring in the XS11 MC is add a front rotor to the left side and drill them using this tutorial:

http://www.xs11.com/forum/showthread...lled+rotor+pdf

Heres a look at mine with two sets of holes using the pattern in the link:



The rotors on your 650 are the same as the XS11

[mharrington]

I have not seen the new o ring available- if recall correctly the O ring is not a typical round O ring- but like the kind in the caliper. I like the drilling idea and may do it on the single disc 650.

[cywelchjr]

I have not seen the new o ring available- if recall correctly the O ring is not a typical round O ring- but like the kind in the caliper. I like the drilling idea and may do it on the single disc 650.

No, I've heard pretty clearly that it's not, and that more than one member has replaced it by taking it down to a GOOD parts house and having them match it up from their o-ring sets, making sure they know it's exposed to brake fluid so they get it from the right batch of o-rings. It would be nice if one of those who had done that had gotten the size of that o-ring they had gotten so we had a size to be able to order without having to go have it matched up.

[Schming]

The best I can measure the two different o-rings, which are both round, is in the first pic:



This second and third pics show the corresponding MC's, which are both stock 11/16" bores for dual calipers on the XS11:





If you check the following link you'll see different bores for the MC's based on application. ie...smaller bore for single disc rotor and larger bore for dual rotors.

http://www.mikesxs.net/products-71.html#products

HTH

[mharrington]

For some strange reason, I was certain the O ring was made from square rubber. I dont know why I thought that. I will take the O ring with me to work and start comparing it to the ones in their index (For industrial hyd oil) Thanks for the help!

[Rasputin]

This may help if you need to look for a different master.
http://www.vintagebrake.com/mastercylinder.htm

[fredintoon]

Hi Mike,
use Rasputin's link to Vintage Brake:-
http://www.vintagebrake.com/mastercylinder.htm
to learn more than you need to know about brake m/c dimensions.
Reader's Digest version.
The stock XS650 m/c bore is too big for it's single disk, it's the same one they put on the dual disk XS650s the rest of the world got.
The Suzi m/c is even bigger so it's even less suitable.
You don't need the dual disk's extra unsprung weight on a tracker and the extra caliper, disk & brake line will eat into your budget big time.
A smaller m/c from MikesXS won't come cheap neither.
OK then, stay with the XS650 stock m/c for now. The reservoir angle on straighter bars hasn't bothered mine in the 20 years since I dumped my rototillers so that's a non-issue.
It'll be the same ol' wooden brake feel as before; you can live with that until you can afford a smaller m/c.
See if you can find a bargain at your local bike breaker.
And yeah, drill the disk, less weight & better braking. Slow speed, heavy drill pressure, lotsa coolant, that disk material is tougher than old boots.
Or, as said, it's the same disk as the XS11, if the breakers has a slotted one it'll save a deal of drilling.

[Rasputin]

Fred. I do not think that the link I posted is "more than you need to know". Many members here look for other master cylinders that will work. Many respond with what will be a too big or too small answer and some reply with a Feel of the brake handle idea. Very few know this info or care to find out. Many could use it from those who chop to those looking for a unobtanium replacement. I think it is just one more link in our arsenal to find what we need to make our bikes, whatever they may be, work correctly.

[fredintoon]

Fred. I do not think that the link I posted is "more than you need to know".

Hi Rasputin,
yeah, you are right. How about "All you need to know - - - "?
Mind you, my brain was starting to hurt when I first checked out that link.
And I do believe my Readers Digest version did explain what was needed.

[mharrington]

I will just run the 650 MC. I removed it because I did not like the angle it has being mounted on non rototiller bars. If the angle is not a problem then it will go back on.

[fredintoon]

I will just run the 650 MC. I removed it because I did not like the angle it has being mounted on non rototiller bars. If the angle is not a problem then it will go back on.

Hi Mike,
the only thing to watch is when filling and bleeding the system.
For that you'll have to turn the steering & perhaps also rotate the m/c on the bars so the m/c reservoir sits horizontal while it's lid is off.
Once it's lid is back on tight the m/c can be tilted as required to put it at the correct operating angle.

[mharrington]

Thanks Fred!