Brake master cylinder

[Whiskeyracer]

Anyone know where to get a rebuild kit or an upgrade for an 93 r65

[mrclubike]

Moto bins in GB
You need to know the Diamter
It is cast into the body
https://motobins.co.uk/bmw-parts.php?model=R%20Series%202%20valve%20Twin&bikeref=R90-6
Are you sure it is a 1993?

[Whiskeyracer]

Thank you. Not a 93 its an 83.

[montmil]

Let the wallet bleeding begin!  

You have the rectangular-shaped master cylinder, correct? Have you disassembled the MC yet? If the bore is pitted or otherwise gerfunken, it may not be useful. Have heard of some folks doing a re-sleeve but that's not always possible.

You may want to look for a used replacement that is in good nick. They are out there. I have had good luck sourcing used Airhead parts from Re-Psyle BMW Parts in the small town of Lithopolis, Ohio. Suggest you call them and discuss your needs. Emailing and going thru their website is about as fast as molasses on a cold morning.
http://www.re-psycle.com/Default.asp

Good luck, amigo.

[Whiskeyracer]

Definitely thinking replace. I had to pound out the piston and the head got mangled.

[SoloLobo]

Go for the new master cylinder complete.... or have yours lined.  I doubt it would still be serviceable as far as only fitting a new piston.

IIRC, Motobins has the best pricing on a complete M/S

[nhmaf]

Ya - might as well replace the whole thing when it looks that bad

[mrclubike]

Moto bins in GB
You need to know the Diameter
It is cast into the body
https://motobins.co.uk/bmw-parts.php?model=R%20Series%202%20valve%20Twin&bikeref=R90-6
Are you sure it is a 1993?

After thinking about what I said here you really should determine what dia should be on the bike and not go by the dia cast into it.
When I got my R65 (single disc) it had a 16mm when it should of had a 12mm

Before ordering also check to see if your caliper is serviceable   No reason to waste time and money on shipping 2 orders
If you need a New caliper don't have a heart attack.
You can use this instead of getting the OEM http://www.mgcycle.com/index.php?main_page=product_info&products_id=1034 

[Whiskeyracer]

Caliper isn't in bad shape so I'm going to rebuild it. And also upgrade to the steel brake lines. Thanks a ton for the info. There will be plenty more I'm sure.