Front Master Cylinder questions

I put some cafe straight bars on my 78 KZ650 project, and as others have found, my master cylinder is too big. It works, but it forces installation of the throttle tube to be sticking out and not pushed in all the way.

So I bought a smaller one from a Cycle shop, off of a new suzuki scooter/moped thing. It's about 2/3 the size, and me and the parts guy just kinda figured that a master cylinder is a master cylinder. Problem: It's not pushing the piston hard enough. After bleeding, the brake works at about 30% stopping power, so I haven't ridden it.

Do you think it's:

Needs to be bled more? Maybe there is still air in there, but I went through almost a whole bottle, until the fluid is clean + about 3 MC's full of extra bleeding so it should be done.

Is there too much brake line? Could this cause it, because there seems to be about 6in extra brake line, but I figured hydraulic fluid would push regardless of length.

Is the MC too small? The scooter it came off seemed to weigh at least as much as a KZ650.

Lastly, is there a major difference between a single disc MC and a dual disc? My KZ is single, but I didn't check the moped to see if it was dual, but that shouldn't matter?

I'm leaning toward it maybe being too small, but I have seen others with pretty small MC's so who knows.

Any input? I'd hate to try to take it back. It looks great on there.:huh:

Ah yes, one little change (like handlebars) leads to another.... Master cylinders (MC) are matched to the brake system they control. Different MCs have different volume and flow characteristics. Even the same brand bikes (i.e. KZ650) used different MCs depending on whether they had single or dual disks. You need to find one that moves the same volume of brake fluid per squeeze of the lever as your original. Ed

No eBay APP ID and/or Cert ID defined in Kunena configurationThis should work for your bike but you need to verify the bar clamp will work with your bar size and the angle of the reservoir is not going to be an issue;



The seller has others for sale and the yhave different lengths and angles so check them out as well first.

I one like this on Bad Juju (superbike bar though) for 4 years without an issue.

So the dual caliper thing isn't an issue? (that one is made for dual, but I guess you're using it with one disc brake?

Good to know.

But that one looks like it's almost the same size as the stock one. Is it much smaller?