? about bad servo motor on M7

Mjunkie

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• Dec 26, 2009

• #1

Over the summer, I put new power valve cables on because the cable housing was coming apart. Didn't do anything else to them, but now the servo motor doesn't turn. I'm pretty sure it is suppose to cycle when you first start the motor, but it doesn't do that, and the check engine light blinks. So I pulled off the motor and did a bench test. I hooked up the power leads to a 12 volt battery and it turned. To me, that would mean that it isn't getting the power to the motor itself to make it turn. The my lights works, so the stator is producing elctricity. My question is what do I check next? Is it the ECU that isn't sending the signal to power the servo motor, or is it something else? Thanks in advance.

 

mmsports

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hubsperformance.com

• Dec 26, 2009

• #2

Check the code

That blinking is a # and it will tell you whats up. The servo does not move when you start it it moves when you get it to about 6500 RPMs.

 

B

bigrodney

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• Dec 26, 2009

• #3

After working on my power valves for the last week. Here is what my servo does on the rack. When you hit 6800 it will make a quick move and that it. I have been told that if no codes flash it should be fine.

Not sure what yours is doing but if the cables are adjusted good and no codes. Look to other issue areas.

My problem was the fuel regulator and I thought it was valves the whole time. check the fuel psi if the stator is good. This is another problem area.

 

A

ARICH

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Dec 5, 2007

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• Dec 26, 2009

• #4

Check the tail light wire at the very end of tunnel, if that is shorting out it will do all kinds of retarded chit, and its very simple to check

 

Mjunkie

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• Dec 28, 2009

• #5

Thanks for the advice. Tommorow I'm going to borrow my buddies servo motor and put it on mine to see if his works on my sled. If his doesn't work either, I'll check out what you guys have said. The check engine light comes on immediately after starting and it blinks at a constant rate, not flash, flash, flash, pause, then flash, flash, flash, or something like that, but I still might get it checked out. Thanks!!

 

D

dgreet77

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• Dec 28, 2009

• #6

Mjunkie said:

Thanks for the advice. Tommorow I'm going to borrow my buddies servo motor and put it on mine to see if his works on my sled. If his doesn't work either, I'll check out what you guys have said. The check engine light comes on immediately after starting and it blinks at a constant rate, not flash, flash, flash, pause, then flash, flash, flash, or something like that, but I still might get it checked out. Thanks!!

Click to expand...

Just went through this on my sled. Thought the Servo was toasted but turns out my power valves were just sticky as hell. A good cleaning took care of the issue.

The constant flashing is usually because the engine is hot....but funny it is doing it right after startup....

 

PowerJoe

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• Dec 28, 2009

• #7

When converting my M6 to a M7 I got an ECU from the dealer to use and then my servo motor wouldn't work. Did all the same things as you to verify that the motor was good. Turns out the ECU I got from the dealer was bad and would not send power to the servo. So it can happen. Try a buddies ECU if you can

I thought the servo DID cycle a couple times at start up, but you can always throw the track on a stand and shift out the clutches to see if it will open.

 

D

dgreet77

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• Dec 28, 2009

• #8

PowerJoe said:

I thought the servo DID cycle a couple times at start up, but you can always throw the track on a stand and shift out the clutches to see if it will open.

Click to expand...

Carbed versions will cycle at startup; as will the older Kings and Mountain Cats. But as far as I know EFI M-series sleds don't cycle at startup.

 

Mjunkie

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• Dec 29, 2009

• #9

Weirdest thing happened. My dad had taken the servo motor home to do some testing on it. He's very knowledgeable with electrical and mechanical stuff, anyways, he said he opened it up and cleaned everything out (said there was some moisture inside), and tested it and found a few dead spots, but said I should put it back in just to see. So I put it in, and now it opens, and the check engine light isn't coming on. I had cleaned the valves just a couple weeks ago, so I knew they weren't sticking. Don't know what the deal was, maybe just the moisture, but thurs. after the storm I'm going riding! They didn't cycle at start up, but when I revved up the motor on a stand it turned and opened the valves. Thanks for the advice!!

 

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Frostbite

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• Dec 29, 2009

• #10

So once you ensure your cable length is correct do you just put the cables back in their respective slot on the servo motor and go?

I also rotated the motor clockwise a bit to take up the slack in the cables and I'm hoping all is well.

It should be fine, right? Maybe I need to cycle the valves on my track stand?

 

D

dgreet77

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• Dec 29, 2009

• #11

Frostbite said:

So once you ensure your cable length is correct do you just put the cables back in their respective slot on the servo motor and go?

I also rotated the motor clockwise a bit to take up the slack in the cables and I'm hoping all is well.

It should be fine, right? Maybe I need to cycle the valves on my track stand?

Click to expand...

Yup. You got it. You can rev it on the trackstand or just run it down the road or whatever if you have any snow on the ground at your shop/garage/wherever. You'll know if its not opening or working properly in a hurry.

 

B

bee1971

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• Dec 29, 2009

• #12

When you reinstalled the cables , i bet the servo spool was 180 Degrees out of rotation

Yes you probably had them installed on the proper side , but at sometime you rotated the servo spool by hand , and reinstalled them 180 Degrees out of rotation

When your old man was cleaning the servo motor , he probably was rotating the motor/servo spool by hand - You can doo this all day long 360 Degrees - However the Servo Motor can not bee / Will not function 180 degrees out of rotation (It will only function properly one way) - It will throw the check engine light everytime out of sequence 180 Degrees

Actually you will see index marks behind the servo spool - Look at the aluminum spool itself when reinstalling cables and make sure there put in the same spots - Mark them with a marker when taking off the cables or just look for the wear/dirt marks in aluminum spool from where they were installed from factory

 

Mjunkie

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• Dec 30, 2009

• #13

bee1971 said:

When you reinstalled the cables , i bet the servo spool was 180 Degrees out of rotation

Yes you probably had them installed on the proper side , but at sometime you rotated the servo spool by hand , and reinstalled them 180 Degrees out of rotation

When your old man was cleaning the servo motor , he probably was rotating the motor/servo spool by hand - You can doo this all day long 360 Degrees - However the Servo Motor can not bee / Will not function 180 degrees out of rotation (It will only function properly one way) - It will throw the check engine light everytime out of sequence 180 Degrees

Actually you will see index marks behind the servo spool - Look at the aluminum spool itself when reinstalling cables and make sure there put in the same spots - Mark them with a marker when taking off the cables or just look for the wear/dirt marks in aluminum spool from where they were installed from factory

Click to expand...

Thanks, I didn't think of that, and that probably is what did happen. Now all I need is more snow and I can go for a real ride.

 

M

Monster700

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• Jan 4, 2011

• #14

m7 problems

I bought an 05 m7 laste year it ran great. Then this year it is running so rich going through plugs and im on a farm so my tanks arent premium so i started filling jugs after about 100 gallons of it still ran to rich then found out ams oil hp is bad on the sled. K so switched oil to arctic cat still same problem with it. Some times when i pin it it just sputters and does nothing from the plugs. Is it the ecu on how they made the 05 run richer. Now the check engine light came on fialure in servomotor could it be the bad oil biting me back makin the valves stick. I need some serious help to get back out PLEASE HELP!!!!