I've recently changed my injectors to bosch ev14 a upgrade from tills in Germany, piece of cake to fit and the bike was great and very responsive then all of a sudden on a ride out the revs went high and idle was 17k ish I backed the idle screw right off until it wasn't touching the base, revs stayed the same. I've checked for air leaks and throttle Cable tension and also removed the tps just in case that was keeping the butterfly's open. Nothing is getting in the way of the tb's to prevent the idle Screw from not seating. I'm thinking maybe the maf but unsure so I'm putting it out there Help............

Forgot to mention it happens when the fan kicks in

Hi Jibe, idle AT 17K I hope you mean 1700rpm
Do we take it that it runs normally UNTILL fan kicks in then is normal again when fan stops,

17K can you imagine... Whoops it ticks over a little lumpy and revs jump up as it gets warm like a magic trick. I cut the engine after the fan kicks in and never waited to see if the revs drop IF the fan stops spinning, I expect my neighbours are planning to string me up.... Temp switch maybe???

Jibe wrote:17K can you imagine... Whoops it ticks over a little lumpy and revs jump up as it gets warm like a magic trick. I cut the engine after the fan kicks in and never waited to see if the revs drop IF the fan stops spinning, I expect my neighbours are planning to string me up.... Temp switch maybe???

Good place to start, 

Jibe wrote:17K can you imagine . . . 

No. The tachometer faceplate numbers only reach 10K. The idle is likely at 1700 revs.

You might be have bumped the idle speed control (choke) lever on the clutch lever assembly or the lever's adjustment linkage down by the throttle switch. Find adjustment instructions in your shop manual and check it.

I've removed the fast idle as I like to twist and go so can't be that unfortunately

jibe wrote:I've removed the fast idle as I like to twist and go  so can't be that unfortunately

You've made yourself quite the bomb there.   It wants to go fast regardless of your intentions.  

This condition seems to coincide with your recent labors; therefore, it seems to me like the disconnection of a plug or mechanical interference is at its root rather than an electronic component's out-of-the-blue failure. 

If the engine was running sluggishly before you installed the replacement injectors, you might need to readjust the air screws on the throttle bodies. If that brings down the revs then you'll need to balance the throttle bodies and adjust the CO.

How long does the engine run before the fan kicks in?

Jibe wrote:I've removed the fast idle as I like to twist and go so can't be that unfortunately

But is it possible the removal is the cause?

The bike idles nice when cold but holds revs slightly when throttle is snapped back. As I said early nothing is getting in the way and the throttle cable has enough play the problem appears when it's nice a warm which is pointing me to the temp sensor. The fan kicks in after a few minutes like you would expect on a early k100 lump as they run hot. Was thinking of hooking up a lead to swap over the resistors!!?? Is this problem ringing any bells to anybody

I suspect that by removing the fast idle control you have allowed the mechanical linkage it controls to float freely, allowing at least one or more of the throttle bodies to open slightly even when the throttle is closed. A warm engine doesn't require much additional airflow to substantially increase the idle speed.

The fast idle control not only opens the throttle butterflies, but also pushes the mechanism to a closed position when deactivated. This is important because the fast idle mechanism overrides the main throttle.

Jibe wrote: The fan kicks in after a few minutes like you would expect on a early k100 lump as they run hot. 

I wouldn't expect that, if by few you mean five minutes or less.  The coolant in your moto might need replacement or topping up; the cooling system might need flushing.

Addition to .75: if you've replaced the TB oetiker clips with worm drives, be sure the fast idle mechanism is not snagging against against the worm drive.

Nothing is snagging. I had the body's off on the build last year and replaced the clips like for like with new. It's doing me head in

Also suspect your throttle cable. Disconnect it at both ends and pull gently to feel for any snags (snags = breaking/broken strands). It only takes one broken strand to screw up the throttle. I think the fan might be a red herring - disconnect it and then see what happens. It won't damage the engine unless you're short of coolant and get it really, really hot.

Double checked throttle cable which is fine. Went to it today and would not fire up, I ended up having a look at the coolant temp sensor all clean and reading 2.2k on both sides happy with that contacts on plug and sensor are clean. When I pull the connector off the bike fires OK soon as I place it back the idle goes up to about 1.5k and then drops to a stall. I'm now thinking maf adjustment as I have fitted the ev14 injectors????