Sustain is in reverse yamaha p-85

No you can't as our PROPER Expert Cindy says.

Casio Ct-636 does not support any sustain pedals.Amazon.comhttps://www.amazon.com > ask > questions
A: Casio Ct-636 does not support any sustain pedals.

The other 'Contributor' probably saw this

CT-S1000V - SupportCasio https://support.casio.com > manualPDF

This Digital Keyboard does not come with a pedal unit. • You can use the PEDAL1 jack to connect an optional (SP-3, SP-20) sustain pedal. You can use the.

every sustain pedal got different polarity.. normally just go to global setting on your keyboard and change damper polarity setting to plus or minus (select which one work with your sustain padle).

Sorry, but the Yamaha pedal has the opposite sense (it is a normally open contact) than what is REQUIRED by Roland equipment. Roland requires a Normally Closed contact. Unfortunately, one is confused because the Roland jack for the sustain shorts itself to no sustain when you unplug a pedal. SOMETIMES one can open a pedal and with soldering iron change a wire to reverse the pedal sense IF the particular pedal has both contacts available.

The function setting is for the PANEL sustain (Page 68 of your manual)

The other method of sustain is by footswitch or pedal option. See page 13.

If you use a footswitch, it needs to be a normally open contact type. If you plug a Roland type in, it is opposite polarity and will sustain UNLESS the pedal is pressed. Make sure nothing else is plugged in the sustain jack... headphones that are inadvertently plugged in there would sustain.

1.Make sure you are plugged in to DAMPER (not FC1 or FC2) 2. Check to see if the notes STOP sustaining when you PRESS the pedal. If that is the case, first try turning off the Roland with the pedal plugged in and restarting with the pedal pressed down. 3. Press the EDIT button and scroll to Damper Polarity. See if it's set to Standard or Reverse. 4. If problem persists after all that, try holding the pedal jack into the Roland at different angles and then try the same with where the cable connects to the pedal. At that point, you can either attempt to repair the pedal or get another one.
Hope this helps, Stewart

It is IMPORTANT to realize that the SUSTAIN is NOT attached to a note, but is an independent MIDI message. Hence it is up to the external MIDI device to associate the sustain with whatever notes are still active.

You may have a pedal that is ROLAND compatible which is OPPOSITE sense from what the Yamaha requires. The Yamaha takes a NORMALLY OPEN contact.

Some Yamaha keyboards such as TYROS have a parameter that you can set to permit using either type pedal.

Some pedals have a switch to change them to use with either type keyboards.

The Yamaha FC-3 uses a TRS (three conductor plug). The PX330 does NOT use TRS jacks for the sustain and sostenuto pedals so they are NOT compatible with the Yamaha FC-3. Therefore I would conclude that continous sustain that the Yamaha pedal would be used for is NOT supported.

What I figured out is that when i turn on the keyboard, if i hold down the pedal by accident, it will work in reverse. I dont know if this is what you mean. If it is, just dont touch the pedal when you turn it on. If it isn't, try to return the pedal. I dropped one, it had this problem, and they gave me a new one. Your cord for it might have been bent (?). Also, turn the keyboard on with the pedal already plugged in. It's not made to be plugged in while it's on. Hope this helps. - Matthew

Not if its like mine, its a completecircuit vs.incomplete circuit problems.

I had the exact same problem with my Casio keyboard and a Yamaha sustain pedal I bought.

I'm not an electrical genius, but I was able to get it to work by opening it up and doing a little modification. Of course I first just tried switching the white wire with the black one but that didn't change anything at all when I tried it. It turns out the Casio wants the circuit completed to sustain, and broken for no sustain, which is the opposite of what the Yamaha pedal does.

I opened it up and mine had three three flat metal strips let's call them Top, Middle and Bottom. The Middle and Bottom ones were joined together on the right side, and the Middle and Top ones were touching on the left side when the pedal was not pressed. These seperated when the pedal was pressed, thereby breaking the circuit because the wires were on the top plate and on the joined Middle/Bottom plate.

So to flip it I:
1. Unsoldered the Bottom wire
2. Cut apart the Bottom and Middle plates on the right.
3. Bent the Middle plate on the right to touch the Top plate instead and soldered those together.
4. Soldered the Bottom wire back on.

That's it! Once I figured it out, it took only a few minutes to fix.
Good luck!
Paul