If you could buy a brand new master cylinder...

[cafetools]

Dog bunny, that link for the 12.7mm ebay MC for only $13... It seems like it might be worth a shot. From what you guys are saying it seems like the smaller bore size is better VS 14 or 16mm.

Edit, however it has no brake light switch.
Please keep the recommendations coming, I appreciate the help. I need to get something ordered within the next 1 or 2 hours.

 

[5twins]

Yes, a smaller bore size is definitely better for "feel" or modulation, but the trade-off is more lever freeplay. I went with an 11mm MC because of all the recommendations but I don't care for all the extra lever freeplay. I need to pull the lever in about half way before anything even happens. Yes, it does give better "feel", much better than stock. I think I'm going to try a 1/2" (12.7mm) MC next. That should give me better "feel" than stock but not as much lever travel as the 11mm unit. I'm hoping it will be the perfect compromise.

I like the used Yamaha MCs off other models for the reasons stated. It's a crap shoot though. You may or may not need a rebuild kit to get it working properly. I think my 11mm unit may need one. It doesn't leak fluid anywhere but if I do a sustained pull on the lever, it will slowly come all the way into the grip. Finding a reasonably priced and good condition unit can also take some time. I watched eBay for a couple months before I found mine for $14. Most sellers wanted 2 to 3 times that.

 

[DogBunny]

Dog bunny, that link for the 12.7mm ebay MC for only $13... It seems like it might be worth a shot. From what you guys are saying it seems like the smaller bore size is better VS 14 or 16mm.

Edit, however it has no brake light switch.
Please keep the recommendations coming, I appreciate the help. I need to get something ordered within the next 1 or 2 hours.

It does have a brake light switch -- shown in the third pic -- you have to know what you are looking for, hard to see in the pic, but it is there. Accepts the slightly smaller spade lugs. The problem with this one for you, is that it comes from China.

 

[DogBunny]

https://www.ebay.com/itm/5x-Right-F...TV-Pit-Dirt-/122064505263?hash=item1c6b9c89af
This is the brake light switch that all of the Chinese M/Cs use. I had one switch go bad, but never any problems with the actual master cylinder. The aesthetics sometimes leave a little to be desired -- in particular the levers are often cast and finished pretty crudely -- but hey, $14.

 

[cafetools]

I think the 12.7 bore size is good on that China shopping MC. Is there any of that same model that are from the USA for the $25 range.

 

[member28833]

USA for the $25 range.

?
Yes , a used Yamaha one !

 

[gggGary]

https://www.ebay.com/itm/Yamaha-Bra...h=item4178d206a4:g:koAAAOSwUdlWcbDG:rk:1:pf:0

5twins you are a master but I think you're right that 11mm you have is leaking or some other defect exists in that brake system you should get a working 11mm and see what you think. I do find that I sometimes have to remove the jamb nut from the handle adjuster screw to get the proper lever travel adjustment, a bit of locktite and it's all good.

 

[cafetools]

I am getting this 12.7mm MC that ggggary posted, but with a black lever. And a $11 black stainless brake line on eBay. All from the USA!

https://www.ebay.com/itm/Yamaha-Bra...h=item4178d206a4:g:koAAAOSwUdlWcbDG:rk:1:pf:0

5twins you are a master but I think you're right that 11mm you have is leaking or some other defect exists in that brake system you should get a working 11mm and see what you think. I do find that I sometimes have to remove the jamb nut from the handle adjuster screw to get the proper lever travel adjustment, a bit of locktite and it's all good.

 

[cafetools]

One question. What's the best way to disconnect the brake wire to get ready for my new MC. Should I be cutting it by the handle bars or unplugging the whole wire inside the headlight ?

 

[gggGary]

https://www.ebay.com/itm/Yamaha-Bra...h=item4178d206a4:g:koAAAOSwUdlWcbDG:rk:1:pf:0

Note; this does NOT have a threaded hole to attach a mirror

5twins you are a master but I think that 11mm you have is leaking or some other defect exists in that brake system. You should get a working 11mm and see what you think. I just went out and made the rounds. I felt and measured the 11mm travel as about the same as stock systems with SS lines. Some modern sport bikes were a bit firmer with less travel. The modified Venture with a 14mm driving 2 4 pot calipers is a bit softer. I have that 11mm lever adjusted for about an inch of freeplay before it touches the piston so that full stopping power is where it is most comfortable for my grip, it still doesn't touch the thick soft silicone grips at full hard squeeze which would be well past tire lock up.

 

[gggGary]

Your existing brake switch and harness easily releases from your MC by pushing in a tab in a slot found on the bottom of the MC.

 

[5twins]

I do have a rebuild kit for my 11mm MC, guess I should install it, lol. I'm thinking that should cure the lever pulling all the way to the grip thing but not sure how it would effect lever freeplay and travel before braking starts? My lever adjuster screw seems to adjust up just fine. I have it set so there is a tiny gap between it's end and the MC piston. In other words, it's not depressing the piston at all which the way I see it, insures I'm getting a full piston stroke when I pull the lever.

 

[gggGary]

You can see I have quite bit of slack before the lever bolt touches the piston.

This does have the early standard type straight lever not the more contoured late model lever.

 

[cafetools]

Your existing brake switch and harness easily releases from your MC by pushing in a tab in a slot found on the bottom of the MC.

Thanks, I nearly destroyed the wire trying to figure that out. Didn't see that at the bottom!

 

[Superjet]

I found this one for $27 from a USA seller. Is it any good ?

https://www.ebay.com/itm/Yamaha-Bra...800563?hash=item4647696673:g:5G0AAOSwL7VWlKWw

I have this similar one, but purchased it from Dime City cycles. I have Goodridge Sniper 2 brake lines and fittings and like it. Not sure how it will work with my Brembo setup I may be on the hunt for another master cylinder too

 

[rick1956]

I bought one of these from Hugh... works great, and believe me--the "blem" was nothing but a little thin paint on the handlebar clamp.

https://www.hughshandbuilt.com/product/hhb-slimline-master-cylinder-blemished/

 

[halfmile]

This looks like it might work for me but the ad doesn`t say what size bar it fits and the cyl says Grimeca brand but it`s listed as a Gripon brand in the text. I tried to email the seller but no response. I`m sure the bikes it`s listed for have a 7/8 bar but sellers other ads are listed as 1". Also it does not give the length of the lever or show if it has a ball end? It would be nice to know more about this.

 

[gggGary]

Bar size, the fit list has a lot of yamaha dirt bikes....
and

 

[halfmile]

Got a reply from the seller a moment ago. Fits 7/8 bar. I ordered one. For $16.50 if it`s junk I`ll throw it away with the rest of the Chinese Crap!

 

[cafetools]

I'm looking forward to installing a new MC. The stock one is pretty ugly. My plastic is all corroded and the rubber layer is dried up on the top and cracking. I figure even a rebuild kit at $25 doesn't even include that rubber top.

I am going to go out on a limb and say that this new $16.50 12.7mm MC is probably better than my 40 year old unit. I will also probably not leak. Also, it can't really be complete trash. Something important like a front brake these manufactures are going to fix and redesign problems over the years. We have to assume that they can't continue to sell faulty dangerous units. .

So for around $16.50 I got a new MC and also a ebay seller was selling a $11 stainless brake line in Black! I decided on black VS shiny silver. I think it will look good. I am glad you guys talked me into replacing the brake hoses as well. Seems safer. Plus I'm never selling this bike... Hopefully. These bikes are getting so hard to find especially unmolested.