Idling issue

[DavidR3R]

Hi guys, took my 2015 Roadster to the dealer because it was surging on a steady throttle at 4000rpm. The revs would increase and decrease about 500rpm either side of the 4000 mark without the throttle being moved. Only noticed it when the bike was run in and I was regularly up in that rev range. Haven’t noticed it happen at any other revs.

Anyway, got it back yesterday and they said they’d adjusted a few things – and didn’t they just!

It now idles at 1200rpm for about 5 seconds on a closed throttle before dropping back to the proper idle around 900rpm. This is a problem because the bike isn’t slowing down properly when the throttle is first closed which makes it difficult to judge when approaching traffic or filtering and generally makes it hard to ride smoothly.

The other thing I’ve noticed is that all the slack has been taken out of the throttle. I’ve got the OEM heated grips so I know from this forum there needs to be some slack to stop the cables wrecking the grip and leaving me stranded, so that’s definitely got to be sorted.

So…anyone heard of this 5 second ‘high idle’ before it drops to the ‘real’ idle’ and is the high idle linked to the lack of slack in the throttle cables?
If it’s just a case of adjusting the slack back in I can do that. The obvious comment will be to take it back to the dealer but I don’t trust their mechanics and I’d rather not if I can fix it myself.

Appreciate your help!

Dave

 

[charlie farley]

Hi Dave,
there should be a little play in the cables 1st to account that the bars pull on them when they are turned and 2nd to allow the cam that is attached to them to sit on the throttle stop as this is the start point for idle air motor to calibrate its self ( the noise well one of them you hear when you first turn on).
i think its about 5mmish rotation of the twist grip both cables if the push cable is tight it will hang up i.e. if your feet up going round in a circle you wont stop .
id take it back and get them to adjust them correctly if they know how.

 

[DavidR3R]

Cheers Charlie, I'm not sure they do know how as they set it like this! Agree on the amounht of slack

 

[idk]

It is not unusual for the bike to rev high for a couple of seconds before dropping back to idle when starting the bike. This is programmed into the ECU when starting under certain conditions. However, after that it should drop back to idle immediately when you return the throttle to 0% - unless you are in gear and moving.

 

[DavidR3R]

Yep!