RiderSite.com - Motorcycle Forums

I went home the “long way” last night and got home about half eight. The Falco was running like a sweetie however for the last half hour I was riding spiritedly and noticed a bit of a glitch when closing the throttle.
It just wouldn’t back off the revs immediately the way it usually does. Normally when you back off the throttle it drops the revs so quickly you don’t need the brakes. Well last night I was finding that the revs just didn’t drop. The revs stayed high, before tailing off after a couple of seconds. It made changing down very interesting.
So when I got her home I checked all the cables and throttle operation and all seems well. No sticking throttles which was what I suspected. So I tightened the cables, lubed em up and tightened up the fast idle cable too.
It was late when I got finished and I didn’t want to wake the neighbours so I thought I’d give it a spin to work this morning. Apart from having tightened the fast idle cable a little too much the falling revs problem is still there.
I’m kind of suspecting a sensor somewhere. TPS maybe or Lambda (sp??) sensor.
Has anyone experienced this before and where should I look next?

Yes, although the delay was very small.
This was due to the fact that I fitted heated grips and have zip tied the power lead to the throttle line. It also happens when I have the tank bag on and route the head stock strap poorly.

So it was the cables in my case, but you have that checked already.

Have you balanced the throttle bodies recently?

Dalemac wrote:Have you balanced the throttle bodies recently?

Yeah I did them at the tale end of last year.

when i balanced mine, i left the rear a bit too rich. in warm air, this causes a similar delay when backing off. I fixed it by turning the rear balance screw in by about 1/8th of a turn.

Obviously, double check all your cables first, and check your sensors.

Dale

Spooky

I had a similar thing happen on Tuesday night!

I was travelling down the M62 at about 6k (revs that is, I know mine is the fastest colour, but) when I exited the M/W the last 1/8th of throttle didn't slow down the bike, not enough to make gear changes a problem, but enough to need the brakes.

Weird

Obviously the same problem with two fast Black bikes just not wanting to slow down!
Just something you have to live with when you ride on the Dark Side!
When did you start the nasty habit of backing off anyway?

Seriously, if you've sorted the obvious cables, I would certainly have a look at Dale's suggestion, unusual but could just be that if mixture is slightly rich on one pot. There are very few obvious options after ruling out the throttle and fast idle cables. The TPS and Lambda sensors in that order are good suggestions as well, but not sure how you would check them, (as never had to do it). I would have thought the latter is less likely, as I reckon it would have been upset when cans were swapped and inductions modified, but does not seem to be.
The other Andy will probably be along in a bit with another sensible suggestion, he's good at faults like this.

Good luck.

check the butterfly thingys are closing and the screwes are tight ,

Maybe your bike's just bored.

Nooj wrote:Maybe your bike's just bored.

...... to 1060cc or 1123cc ?

.... though I doubt that would give this problem

Tsk!

Bored as in it wants to keep going and have an adventure.

I'm with Joecrx, check the butterfly screws are tight.

D-Rider wrote:

Nooj wrote:Maybe your bike's just bored.

...... to 1060cc or 1123cc ?

.... though I doubt that would give this problem

And I said you'd be along soon with a sensible appraisal !

Well after tightening up the cables, adjusting the "choke" cable and getting her all settled down I rode the Falco to work today and everything seems fine.

Dunno what went wrong.

Weird.

Oh and this weekend I might go out and play on the big red Honda for the first time.

I do hope the Falco doesn't go in a strop cos of it.