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YPVS servo test

Posted: Wed Oct 19, 2016 2:14 pm
by RBP3
Good afternoon all,
I tested two RZ500 YVPS servo motors (connected black/red & black/yellow only directly to the battery) as per Troubleshooting Chart 1 on page 7-49 of the Service Manual. Both turn freely & smoothly but in opposite directions of what the test shows to be correct. Is the manual incorrect or do I have the same problem with both servo/potentiometers?
Thanks much,
RBP

Re: YPVS servo test

Posted: Wed Oct 19, 2016 2:33 pm
by MK
Switch cables and if turns the other way, everything is fine.

Re: YPVS servo test

Posted: Mon Oct 24, 2016 1:17 pm
by RBP3
Thank you for the reply Martin. The test I'm referring to (servo plug pulled & servo connected to a battery by the black/yellow and black/red wires only) says when the black/yellow wire is connected to positive & black/red is connected to negative the servo should turn clockwise. Both I tested turn counterclockwise. Also, when the wires are switched the manual says the servo should turn counterclockwise. Both I tested turn clockwise. The cables are correct as per the manual. If I switch the cables I doubt that the oil injection will operate correctly since that cable is also connected to the servo pulley. Should I switch the wires? Either the wires or the manual are incorrect.
Thanks,
RBP

Re: YPVS servo test

Posted: Mon Oct 24, 2016 5:22 pm
by phildu31
Hello.

The manual is correct. It's surprising that you have two motors with wires inverted.
So it's possible that your control box has wires also inverted.
Don't invert the cables as, like you said, the oil pump wouldn't operate correctly.

At the end, the only thing that counts is that the ignition sequence be correct.
Turn the ignition key ( without kicking on ) and the sequence should be : valves closed -> opened -> closed -> opened.
When the engine is started, the valves should close.

If you're not sure of your wiring, it should be better to test without the cables, but I don't remember what the sequence should be : clockwise vs counterclockwise.
If needed, let me know and I will look further in the bike.

Phil.

Re: YPVS servo test

Posted: Mon Oct 24, 2016 6:39 pm
by RBP3
Thanks for the information Phil. Both servos turn in the wrong direction when sitting on my workbench with only the black/yellow and black/red wires connected to the battery. With the servo installed & the key is turned on the power valve does not open - close - open as it should as you & the YPVS test say it should. Even if I manually close it and then turn the key on it only opens, pulls slightly toward closed, and then appears to pull past full open. Good to know the manual is correct. That puts me a little closer to solving this problem.
Thanks much,
RBP

Re: YPVS servo test

Posted: Mon Oct 24, 2016 8:08 pm
by phildu31
So you can invert the wires.
Also check the potentiometer of the servo motor with an ohmmeter on the 3 other wires ( white/black, white/red and yellow/blue ).
This potentiometer sends the position feedback to the control box. It is not a power component and should be fine but worth the check.

If all that is good but the servo motor still doesn't operate correctly, it is your control box that needs to be repaired/changed.

Phil.

Re: YPVS servo test

Posted: Tue Oct 25, 2016 10:01 am
by phildu31
Hi,

Checked on the bike to be sure.
The servo motor and the oil pump lever will both turn clockwise when opening the valves.
And counterclockwise when closing the valves.

If you stop the engine with the ignition key from idle, the valves stay in closed position.
If you stop with the kill switch ( power still on ), the valves will move to the opened position, ready for the next start.

So, depending on the initial position of the valves, the power-on sequence will be :
optionnal : closed position -> clockwise rotation -> opened position
and always : opened position -> anticlockwise rotation -> closed position -> clockwise rotation -> opened position

Phil