What size front master cylinder for kz305

Thinking of keeping my bike and just keep fixing everything until I put so much money into it that I can never sell it.

What size master do I need for my 305 single front disc? 13-14mm 5/8s?

Also looking for the best site to order one from. Currently dime city cycles seems to be the best. I am in Canada so any Canadian sites would be great.

Single front disk brake system uses 14mm bore master cylinder. Dual front disk brake system uses 5/8" bore master cylinder. Ed

The Fr Br mc on my 81 650-CSR has 1/2 cast on the underside of it. 1/2" = 12.5mm. I'm assuming it means 1/2".
You can probably use one from a Ninja 250 or something. usa-motorcycles-inc has various new aftermarket.

Thanks guys.

The EX250 has a "dummy cap" in the mc --- hopefully the hole where it fits is threaded to accept a mirror.
Some modern mc's don't have a mirror orifice.

I've installed bar end mirrors anyway and have a renthal bar so I need a smaller master reservoir as my stock on currently hits the mounts.

I'm also not sure how the front brake actually works since the fluid in the resevoir is crusty and very low.