idle problem

[smiffy-0]

Hi new to the site so please go easy on me ive a gen 3 model (2016) and the bike after 25k miles the idle has started to slightly increases when say stopped at a junction and sitting in neutral , ive just had the valve clearances done and was hoping that may of sorted it but no luck, could it be the throttle position sensor? any ideas would be appreciated.

[Seeker]

Welcome. You certainly ask difficult questions.

I have no idea what is causing your problem but here's a few random ideas. Idle speed is controlled by the ECU via the ISC valve which is part of the throttle bodies (T-ISC?).

Idle speed should climb (on a Gen 3) when the clutch release switch is sensed (when in gear) to about 1500 rpm - is that still working?

Idle speed is raised for cold starts - maybe a temp sensor is not working correctly?

Out of curiousity, what rpm does it climb to? Does it keep climbing or stop at the same value.- Does it do it with a cold engine or just when hot? Have you tried reseating connectors (ECU, throttle body etc) whilst looking for corrosion? Do you power wash the bike? Is the bike stock?

Do you get on well with your local dealer? (j/k)

[Craig380]

All of what Seeker said above. In addition, check the clips securing the airbox to throttle body boots, and throttle bodies to cylinder head boots are snug and secure. After 7 years they may have relaxed a bit and allowing tiny air leaks at high vacuum, i.e. idle speeds. I found that they were not particularly snug on my own bike.

You need a L O N G 3mm Allen key or a 3mm Allen bit on a flexi extension to get at the clips for the front cylinder.

Worth checking the two rubber hoses that lead from the IAP sensors at the left rear of the airbox too. I remember a guy on the US forum had a random low-speed running issue with his Gen 3, one of those hoses had developed a split in it from chafing and that was throwing out the inlet pressure reading for one cylinder.

Let us know how you get on.

[Bibio]

same as above. my K7 does this if i leave the large hoses from the air box off.

tbh if you have just had valve clearances done and the problem has just started then take it back to the person that done the valves (unless it was yourself).

[smiffy-0]

Hi all thanks for your replies, it started before the valve clearances were done, but as seeker has mentioned about the idle increasing to 1500 RPM when put into gear this i only noticed happening Sunday just gone and most certainly hasn't been happening for the last 2 1/2 years I've owned the bike, the guy who did the valves said he had run a diagnostics test and cleared some errors that showed up, I've just started the bike up just now and when put into first gear the idle is staying at about 1250 rpm not increasing to 1500 rpm like it did on Sunday, is it something i should be concerned about or just see how it goes and live with it. Damon.

[Seeker]

Just to clarify - the "in gear" revs should only climb as the clutch release switch is sensed (ie the ECU recognises the clutch is being released) - it is to help new riders avoid stalling. If you're in the habit of releasing the clutch and opening the throttle to smoothly set off you wouldn't notice it but a novice rider that might not be so coordinated and releases the clutch without giving enough throttle would be helped by the bike's intervention.
If you put it in gear, slowly release the clutch (no throttle) you should see the revs climb as the clutch switch changes state.

[smiffy-0]

that was defiantly the case on Sunday, releasing the clutch with no revs and they increased to 1500 rpm, ill have a go tomorrow after work when its light and let you know what happens. Damon.

[Craig380]

You can use clutch assist when trickling in first gear in traffic, modulating the clutch lever at the bite point also gives a gentle lift in rpm without any throttle input.

[garynortheast]

Any resolution on this now, Smiffy?

[smiffy-0]

Hi, yes all is as it should be now, the bike had after market levers and the clutch lever wasn't activating the switch, put some OEM levers on and all is fine.