Master Cylinder issues?

I just picked up my first KZ bike. I have always rode Hondas and Yamahas. I like it so far. It is a 18978 KZ650SR. It has dual front disc brakes. The brakes were spongy so I went to bleed the brakes again. When I took apart the master cylinder I noticed that the gasket was ripped and the entire cylinder was a mess. I decided to throw on a new master cylinder because I don't want to wait for a rebuild kit since I would like to ride before it snows (I live in Cleveland...it could happen). I threw on an aftermarket master cylinder. i bled the brakes, I am positive that there was no air in the lines. I cannot get the pressure in the lever to build back up. I went through these things a hundred times. The only thing I can come up with is that maybe my master cylinder isn't big enough for the dual system? Is that possible? Or am I missing something? I've never had a dual front disc, so i don't know the systems that well. Thank you for any help!

bleeding brakes can be a major drag to say the least!
put a piece of clear vinyl hose like they use on fish tanks on the bleeder valve and watch for bubbles as you bleed the brakes.
ive had to pump the hell out of the lever and zip tie it down to the bar to keep pressure on it overnight then crack the valves open plenty of times to get pressure to start in system before

I use a pressure bleeder (KD-2222). It pushes fluid from the tank through the M/C to the bleeders. One nice thing is that you can open both front bleeders at the same time and let 'er flow until clean fluid comes out both sides. I made the adapter from an old M/C cap. If you can find a friend with a service station they may have one of these units. If so, all you need to do is make an adapter. Let me know if you need help with that. My wife bought this for me as a Christmas present years ago so I can do the brakes on our cars and truck without needing her to pump the brake pedals. :laugh: Ed

Thanks for the help guys! It ended up being that the master cylinder was too small for dual calipers. I just took one of them off, problem solved. haha