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APV servo motor turns the wrong way (counter clockwise)

8K views 8 replies 4 participants last post by  optistartremote 
#1 ·
I have a 2002 ZL 600 EFI.
I just spent two days trying to get my APV servo working properly.
I have two servo units.
I disassembled both (one at a time) and cleaned the commutators, brushes and oiled the bearings.
I took out the potentiometers, disassembled them and cleaned the carbon tracks and brushes (everything was fine to begin with).
I can supply 12V to the motor terminals and the motors spin as they should. Reverse polarity and they spin the opposite direction as they should.
I used a digital ohm meter on the pots and they are smooth and work great. No glitches in ohm readings when turned slow, nice and even sweep readings.
Both of these servo units are in great shape and work and test well out of the sled.
When I put EITHER of them in the sled, they turn the wrong direction. They are supposed to turn clockwise to pull the cables over 7000 rpm. They turn counter clockwise then stop in a downward position instead of where they should stop (about 7-8 o'clock).
That lead me to believe I may have put something together wrong inside. After many hours of taking both apart , inspecting and installing to retest. I am sure they are together right.
So my thought is the ECU is sending false or bad signals to the servos.
Yes, the ECU will flash 6 times once the servo cycles. Then I have to manually rotate the servo to a different position and restart the sled so the ECU light does not flash. All is well until revved up past 7000 and the servo cycles (in the wrong direction) then the ECU flashes 6 times indicating a problem with the servo. Manually rotate servo, start , no light is flashing, rev, cycles wrong, repeat....
I can replace the servo unit with my spare unit and the same thing happens.

Now. before I buy a new CPU, is there any way I can test mine to confirm it is bad?

The next step would be to swap my ECU with a known good one to be sure mine is bad before I buy one.

Does anyone have an ECU I can use to confirm mine is bad?

My ECU number is 3005-967 (33900-88BK1-OBO EC7262) it has the square symbol on it.

Thanks.
Danford1
 
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#2 ·
I had a similar issue with my F5....turned out to be damaged wiring. The 2ndary had nicked the wiring bundle when it went fully open.
I, too, dis-assemble the servo motors & bench tested them with good results. Check the wiring before you start swapping ECU's.....hope it's sumpin simple in your case.
 
#3 ·
I think I fixed it.

I think I fixed it. I say "think" because for the moment it is working. I'll have to wait until I can ride it to be sure.
Sometimes you just have to walk away from a problem then revisit it another day with a fresh mind.
I figured the servo must be in the wrong starting position and when the computer sent the signal, it would go in the wrong direction.
I pulled the cable pulley off then turned the shaft 180 degrees and installed the cable pulley again.
It worked !
But I also was playing with the connectors coming from the magneto and checking ohms. I didn't see any corrosion or any loose connections, but , it is working now so I'm going to leave it alone.
Thanks for the help and guidance.

Cheers
Danford1
 
#4 ·
I want to resurrect this old thread of mine.

My power valve troubles never went away. I hooked up a light bulb to the wires on the power valve so I can SEE when the valve opens while riding. It sometimes works and sometimes doesn't work.
I think the CPU is bad. Where do I get another CPU? How much are they?

My ECU number is 3005-967 (33900-88BK1-OBO EC7262) it has the square symbol on it.

I want to get this sorted out before this season starts.

Danford1
 
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