C28 FI error after winter break

[slimjim650]

Hi,

A few days ago I brought my 2006 DL650 out of winter hibernation. It’s been sitting unused for about 4 months which is the longest I’ve ever left it as normally I ride pretty much all year.

Anyhow first ride out I notice a massive drop in power at high revs. Bike feels like it’s been restricted or in limp mode. Then I see the red light on the clocks and the FI error on the LCD. Back home I read about the dealer mode and make that change on the connector. Error code is C28 (secondary throttle valve actuator) and happens after about 5 -10 minutes of riding - but the power drop is present all the time.

Further research and I’m beginning to understand most likely cause is something has seized in the throttle bodies. It’s a little out of my comfort zone but I’m probably going to attempt a repair myself. There’s quite a lot of stuff to take apart and put back together before knowing if it’s going to work, so I’m a little hesitant. Could anything else be causing this? Any quick fixes or tests I can do before the tank comes off?

Cheers

[greywolf]

Most of such cases involve a stuck butterfly and WD40 is the usual cure. The book says any of the following may be the culprit. I haven't heard of any motor problems so the valve itself or the wiring to the motor are about the only real possibilities otherwise.

STVA malfunction.
STVA circuit open or short.
STVA motor malfunction.

[mr_diver]

I had this fault on my k6 wee.

Turned out the secondary throttle mechanism was gummed up.

Off came the panels, tank and air box.

Nearly a full can of WD40 and plenty of hand turning the mechanism by the nut on the end of the actuator shaft cleaned out the gunk.

Never had any other issues over the next 35k miles.
I did however keep spraying the area with wd40 whenever I had the tank off.

[slimjim650]

Thanks to you both. I'm going to get a large can of WD40 and give it a go. I've noticed a bit of corrosion appearing in various areas so I highly suspect the mechanism is gummed up.