Exhaust Valve Servo Motor not happy!

[Whitey]

The servo motor for the exhaust valve on my 2010 GSA sometimes continues to whine after completing its calibration/test when the bike is first turned on. It seems to happen after I’ve been for a run and the bike is hot.

Most times when turned on from cold the bike cycles the valve then rests up ready for the engine to be started. I thought it was the valve sticking when hot but today I removed the cables from the valve and tied them out of the way while I went for a ride.

On first turning on the bike, it did the calibration cycle (cables went in and out) and was then quiet. But, when I got back from my ride I turned the bike off, then when soon turning it back on again it did it’s test cycle (you can see the two cables moving in and out) then again carried on whurring from the servo motor. The cables weren’t moving, and the noise is an on/off buzzing/whining sound, (like a stuck motor that keeps attempting to move). As the cables aren’t moving and they aren’t connected to the exhaust valve, it can’t be the valve sticking.

So any ideas what’s making the servo keep buzzing after it’s done it’s test cycle?

I haven pulled the cover off the servo yet and removed the cables as I wondered if there was anything I should test with them still attached.

I thought I had this solved and was ready to leave the valve in the open position and remove the cables,, but this has me confused. Any ideas?

If it’s relevant, I removed the can and had eyes on the valve when the cables were attached and the engine was running. It seems to idle at just off closed and then open a bit as the revs rise, but never fully open - a bit over half, 3/4 maybe.

The valve is lose and moves freely by hand when cold.

The same when the cables are disconnected from the valve, it doesn’t seem to pull the opening cable all the way back… not sure if this is right or not.

Any thought on the matter? Is a sticking servo motor a know issue?

Thanks


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[dub 24]

Hey Whitey . I had the same problem,well known problem with these. As recommended I removed the valve altogether and replaced it with a piece of exhaust pipe. I removed the cables from the servo and blocked the holes where they came out with a plastic reg plate nut and bolt and with a good dollop of sealant to protect the innards from water and crud. You don't get any warning lights on the dash and it doesn't effect performance in any way.
Hope this helps.
Cheers
Dub 24

 

[Whitey]

Thanks Dub 24, that was the route I was going to take but the noise from the servo motor with the cables disconnected from the exhaust valve made me think there could be another issue.

Does your servo motor still make a sound like it’s struggling to turn even after you disconnected the cables. Beyond the usual start up routine I mean.

If so is I case of just letting it chirrup away and ignoring it?


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[dub 24]

Can't remember to be honest gimme 5mins and I'll go to the garage turn on the ignition and report back

 

[dub 24]

Hey mate PM me your number or email and I'll send the pictures I took and the little video clip of the unit during start up

 

[Slipperyeel]

Sounds like the servo it's having trouble, exactly as you think. If the exhaust butterfly is working on as you describe, I'd just find a replacement servo from somewhere. Probably some in garages as people do disconnect these when the butterfly becomes jammed - I think that's the expensive bit!



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[Mistacat]

There is not any difference whether you disconnect the cables at the motor or unplug and remove the motor assembly.
Both options show the same fault code when you scan the ecu, but nothing on the dashboard.
There is a device from https://www.healtech-electronics.com/products/ese/
If you don't want any codes on the ecu after removing the flap and motor assembly.

 

[Whitey]

There is not any difference whether you disconnect the cables at the motor or unplug and remove the motor assembly.
Both options show the same fault code when you scan the ecu, but nothing on the dashboard.
There is a device from https://www.healtech-electronics.com/products/ese/
If you don't want any codes on the ecu after removing the flap and motor assembly.

On that note, I’ve removed the whole lot and problem solved. I don’t have any diagnostic equipment and I can confirm that no warning shows on the dash. So, as long as the ecu isn’t getting confused by it’s absence I’d say this is the best option.

Many thanks to all who’ve chipped in, most helpful.


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