One of the pads always will touch a little, because there is only one piston in this design. Lift the front wheel and spin it. you will hear the slight contact, but the wheel should spin freely. If it doesn't the sliders are dirty and will need to be cleaned.

Not long. Sounds like the caliper may be froze up, or as arteacher said, the sliders are froze up. (where the caliper slides back and forth. ) Also, the pads themselves may not be able to move. Sometimes they fit real tight. You may need to file the edges a little where the pad contacts the caliper. A light coating of Sil-Glide brake lube on all the edges where contact is made helps prevent this from happening.

As far as the rotor turning blue---not a good thing. Overheated from brake pads dragging. Once that happens, the rotors are usually junk. Severe overheating creates hard spots, known as heat checking. Sometimes they can be machined and saved....usually not. The pads might be able to be saved, with some light sanding, until they return to their original colour. In most cases, though, the pads would need to be replaced also.

Not what you wanted to hear, I know. Next time around, make sure the wheel spins freely AFTER applying the brakes a few times. If you can feel it dragging, something ain't right. I assume you put on a few miles with it dragging---turning a rotor blue doesn't happen easily or quickly.

On a caliper that has been used for 23 years, and has probably seen less than marvelous maintenance for at least some of those years, it would be a miracle if the caliper is still smooth and shiny inside.  The piston is not moving smoothly and retracting to its proper position when you let go of the brake lever.  (the most likely problem on an old, well-used caliper)

There are lots of other possibilities: the caliper is not sliding smoothly over the bolts it rides on,... or the seals are sticking inside the caliper,.... or the pads are not moving relative to the caliper,.... etc.

The whole assembly has to be clean, corrosion-free, no pitting, smooth sliding surfaces, with flexible boots and seals, and very slightly lubed in order for it to work properly.  It is amazing that disc brake systems like this work so well when so many things have to perform properly for it to work at all!

Bad news / good news .........  
 -- Bad news: You may be looking for a new caliper soon.  
 -- Good news: A used caliper is as good as a new one if you can verify the cylinder inside is smooth (no pitting or corrosion), and you get all new expendable parts (seals, boots, etc.)  At Ron Ayers, a piston with a piston seal and dust seal is about $24.    

Clean up the pins the caliper sides on.

I cleaned and greased the slides.  It seem like it is working properly now.  Just to check I stuck my hand down ne'er the rotor to see how hot it was got after I rode it down the block.  I could still feel heat comming from the rotor but it isn't near as hot.  I'm not sure if it is normal or not to have heat from the rotors after about 4 blocks or so with very minimal breaking (only got it up to about 30).  If so how hot is too hot?

So the brakes are fixed and working as advertised.  But while I was riding the engine started to bog down and fuel started pouring out of the left side bowl vent on the carb but not the right side.  I know that this issue has probably been addressed many times in the past.  I was wondering what the problem might be.  Everything on the bike is stock.  It has never been rejetted to my knowledge.  I also have a stock, probably original petcock.  Stock airfilter.  Any help would be appreciated.
Thanks

justin_o_guy2 wrote on 09/16/11 at 18:50:09:

+1

not while it's running