Ok I'm not even sure I have a cb450 caliper or a 750 caliper. Having no knowledge if there is a difference between the two. The reason I say this is because I had an issue with a caliper and the piston was stuck in there, and after blowing it out with a compressor and trying to clean up the piston, it was definitely trash. I was given a cb750 piston and caliper, though still have the 450 backing plate. Long story short, I have both, and it's not working. Can I get it to work correctly on my cb450, or is the 450 piston and caliper completely different? The exact problem is they are tight right to the rotor and no amount of adjustment in the caliper swingarm is changing anything. Can anyone help?