750 Seca bar-mounted master cylinder conversion

I got tired of messing with the dreaded master cylinder on my Seca, and decided to replace it with a standard bar-mounted unit.

Required things:

1. A big-bore master cylinder, without the angled reservoir.
2. Aftermarket handle bars, cause otherwise you'd have to lose the covers
3. Right-hand controls (since the original set has the brake lever mount built-in)
4. A brake line splitter and a piece of brake line (12-14" or so)

I used the master cylinder, splitter and the controls from a donor 650 Turbo Seca. I hope the soon-to-be-rebuilt Turbo won't need them! :roll:
The standard 750 Seca throttle cable does not have enough of a tail on the top, so I had to carve on the throttle tube a bit so that it would not keep the cable tight.
All of the wires inside the control box had to be re-soldered. The gang plug on the end is the same on both bikes, but the pin-out is different.

The end result is much smoother brake action, less creaking in the front, and more breathing room for cables and such behind the headlight.

Here's the switch I added to the Turbo controls (1.5A, Radio Shack):


The control body had to be carved a bit...


Inside of the control body... I put the switch as high as I could so I had room to add another one in the future (who knows what I might need to switch!)


The splitter ( I had to drill another hole in the mount so the splitter would be centered)


AAAAGH!! Kill it with fire!!!


Controls and MC mounted to the bars


Another view...


All done!


Bonus bike pic


My (kinda hungry) helper.

 

nice, is the right hand control absolutely necessary? I am about to do this, and see that my new R6 master cylinder just clips to the bar.

 

It's not 100% necessary, but you'd have to grind off the mounts for the original brake lever. I did not want to damage the original parts, so I went with another set.

 

got'cha. I don't give a crap about my bike's originality, so I'll just be grinding away.

God that non-bar mounted MC was a dumb idea on yamaha's part.

 

why not get two brake lines and do away with the splitter then that whole bracket thing can get pitched and just use some cheap headlight ears
then the whole front end is cleaned up

 

Sweet seca my friend. Once I get all my cylinders firing this will be my next project. I'm really looking forward to having a front brake again. -_-

 

Haha. I was wondering what the heck that thing was. I have two (project) 750's, both with bar-mounted master cylinders. It appears this is a popular mod. The non-bar-mounted cylinder seems to be bypassed on one bike, not on the other. The breaks seem to work on both.

 

I'm doing this as soon as I have the extra $$$ for the lines. I had to use what I had on hand, save the MC rebuild kit.

Hey, thanks! I have other plans for this bike, but there are two other projects sitting in the garage. Gotta make some room.... Keep us updated on your project!

 

I have very little experience with brakes and hope someone can provide guidance
I have the Master cylinder from Mikes XS in my wishlist
16mm bore.(Wondering if that is big enough) :?
OEM type. Complete with brake lever, brake light switch, banjo bolt and washers.
$79.00
Is this a good buy for my application?
I will be doing 2 SS lines direct from the MC to the caliper. Phasing the anti-dive out.

 

It will work, but you would have to bypass the level sensor... Who cares though -- you have the sight glass!

 

Will definitely love having the r6 MC. looks so good, and brembo parts > yamaha perts!