Brakes - ID and quickfix rec

[puftas]

Can someone help me with an ID?

I'd been operating under the assumption that my MC assembly was stock to my 77D, but from what I can gather from forum/manual that's not true?

In any case was poking at my misty level-gauge and it crumbled under my fingernail. Yes that's brake fluid coming through the center.

Would like to replace without redoing fitment/hosing. Best option I could figure out is this on Mike's: https://www.mikesxs.net/yamaha-xs650-1mh-master-cyl-assembly-13mm-bore.html

I can't tell if that's the right size though. Only marking I could find on current MC was a small "SD" logo. Standard?

Manual states 77 is first 14mm year, but that stock replacement says 13mm.

as always, any advice is much appreciated.

 

[jetmechmarty]

For new, your best move would be to call 3M (Michael Morse) at 650 Central (www.650central.com) You call and talk to him and what you get will be right.

Or buy a used OEM one on eBay. Rebuild kits are cheap. (www.georgefixs.com) OE brakes feel a bit wooden. Call 3M to do better.

 

[gggGary]

Yeah that's not stock

But that might be fine.
Kinda down behind the handle bar they usually have the bore size marked, that's the most relevant MC thing.
Well and yeah your MC IS in desperate need of cleaning at least.

https://www.xs650.com/threads/front-brake-master-cylinder.57923/post-655822

 

[5twins]

For better modulation and "feel", many of us downsize from the stock 14mm to an 11 or 13mm, or a 1/2". The 1/2" will give a slight improvement in "feel", the 11mm even more but at the expense of more lever travel. I get used ones off eBay from other Yamaha models. You can usually score one for $20 to $30 if you shop around and are patient .....

The only replacement parts needed on both of mine were new top screws.

 

[puftas]

Thanks for help guys. I'm correct in thinking if I change MC bore I have to change hoses? Thats my main question.

Had seen Gggs chart and 5twins reccys, just didn't have this answered anywhere explicitly

Had no problems with feel on what I was running, so wondering if it is actually 13 already? Couldn't find a listed diameter anywhere on that MC. Looked closely too.

 

[grizld1]

Every factory manual for every Japanese motorcycle I've owned (Honda. Kawasaki, Suzuki, and Yamaha) has specified a 4 year service life for rubber brake lines. Braided stainless lines have no replace-by date. Yes, if you reduce MC size you'll increase line pressure and that means better lines that will not lose every potential gain to flexing. I installed a Brembo MC, braided stainless line, and Brembo rotor from 650 Central around 15 years ago and couldn't be happier. Your bike, your hide.

 

[puftas]

yep, I already did stainless upgrade a while back, but I'll go you one further: redid them twice cuz the first two braided hoses I got (mikes I think) failed on me after a season or three. Popped right open where the hose meets the coupling, thank f*ck I was just flexing on my brake lever at a stoplight and not on the highway. Upgraded again to DimeCity braided lines, and no problems there since then.

 

[jetmechmarty]

Upgraded again to DimeCity braided lines,

MikesXS & Dime City are both in the same building with Z1 and Randakks under the Revival Parts umbrella. I once bought a stainless hose from MikesXS and the quality was very poor. Z1 was selling first quality Goodridge hoses. Now, those four businesses have their catalogs mixed. So, Dime City has the first quality Goodridge hose and the junk MikesXS hose. MikesXS also has both. When shopping there, you need to know what you're buying.