Caliper write-up
I recommend that every time you change your pads, you service the calipers, he's my write-up to help you out. It should fix your initial problem, and keep your calipers in top working order.
I also recommend flush and fill with new brake fluid, also I'd go with 5.1DOT.
No matter what kind of brake fluid you choose, always periodically flush and fill with new fluid.
This is the one I use
https://m.motul.com/ca/en-us/product...-1-brake-fluid
Also inspect the brake lines, replace is needed,
http://faq.ninja250.org/wiki/Stainle..._lines_upgrade
I have these stainless steel lines on my Ninjette, and so far, some good, I recommend getting the stainless steel banjo bolts, I noticed my chrome ones have started to rust slightly, a good excuse for me to upgrade to titanium
On my 91 EX500 I have Spiegler, in orange to match that bike.
When it comes to safety items like brakes, when in doubt, throw them out, it's your safety in your hands, and is cheaper than a visit to the ER.
Buy quality pads,I personally recommend EBC brand either the HH, or the Extreme HH.
EBC full floating rotor, replace the OEM rubber line with a stainless steel braided brake line, cheaper than replacing them with OEM.
On my 500 I have Spiegler line
http://www.spieglerusa.com/brakes/cy...line-kits.html
On my Ninja 250 i went with Venhill
http://www.venhillusa.com/products.html
With all that, it will stop on a dime, and leave you nine cents in change.
look here
http://ebcbrakes.com/products/motorcycle/
And also read this,
http://www.ex-500.com/wiki/index.php...otors_and_Pads
That should answer any questions you might have.
And of course my response about the magic of SS lines. Don't get me wrong I have them as well, but I used them as replacements for old OEM ones that needed replacing anyway, not to gain performance.
All this BS about SS lines is usually caused by poor caliper/disc condition. the brake system is notorious for binding slider pins that warp the disc. this warp or coning of the disc is what causes the long travel of the lever as the disc must be bent straight before it can be clamped properly for hard braking.
This longer travel is caused by the disc retiring to it coned condition which pushes the pucks back too far into the caliper.
You must get a flat disc and replace the pads after to clean and re lube the slider pins. Then bed in the new pads to get a good brake. The SS line alone will do little or nothing.