Bike reving at 4k

[Nick Hood]

I have just started up my fz1 after a two month rest. It starts ok but after a couple of minutes it ticks over at 4k. I took it out for a 8 mile run . Everything seems fine power  wise but when you stop or pull the clutch in it's back to the 4k. It's not the idle adjustment screw. Any ideas ?

[Deefer666]

Snagged throttle cable? something in the swtchgear?

[Nick Hood]

No its not that Mark. Nothing's moved. The clue must be its ok when it starts, but after the warm up then it revs high.

[Falcon 269]

I think there's some kind of coolant temp thermo-couple device which controls the fast idle/cold start mechanism.  That's where I'd be looking to start with.

[The Male Whale]

Not personal experience but one of my customers had the same issue on his FS1 after a longish lay up.

A good blast and some fresh petrol sorted him.

Whale

[Nick Hood]

The tank was on reserve when I took it to the petrol station. It's done 4 miles after a fill up. Will a yam dealer have some diagnostic equipment that will find the problem

[Deefer666]

Oh the FZ1 has FI doesnt it? Hmmmm I havent had a good look at the fuel system on them... Are they auto choke or manual?

[Spud]

Could be the throttle position sensor.

[DekF]

Mike as ever is on the money.
The rod on the thermowax unit will be sticking.
Get the temp upto 75+, raise the tank and see if the plunger is pushing down on the throttle linkage.
If it isn't try wd40 and to physically move it.
It's not uncommon on the gen2 and is an easy fix.

[Gnasher]

Put it in to diagnostic mode and read the codes if any. 
  Main suspects are air/water/fuel temp sensors or the thermo wax, could just be damp, stuck, out of adjustment or one of them has packed in.  Sounds to me like the ECU thinks the engine is cold when at idle because one of the sensors is telling it the engine is cold when it's not you just got to find out which one/s, it could be other things but start here first.   

[DekF]

There is no need to complicate or overthink the issue.
The symptoms he describes are exactly as hundreds of us gen2 owners have experienced.
It is in almost every case a simple fix by freeing up the thermowax plunger.
The thermowax unit incidentally won't give an error code.

[Nick Hood]

Thanks guys i will have an explore inside the dark depths below the tank tomorrow. The light in the garage is a bit dim, so weather permitting I will have a look outside.

Nick

[Nick Hood]

Fixed it. It was the thermomax widget that couples with the thingy that auto couples with the tick over watsit.

Nick

[pitternator]

You will not outfox Dek on gen2 issues.... verily he is the master  !    8)

My only comment Dek is when you mention " hundreds of gen2 owners" ... was that not  being a bit over ambitious ! 

:lol

at least on my gen1 my only issue is " sticking ear wax" .... largely due to old age of the donor !