guys, i need your help. my f4i is idling to high and the idle **** does not do anything. i took the bike apart to look at the cylinders under the air box, and thought the lever that is set against a stop screw is holding the butterflies open, so i adjusted that and it worked for literally 15 seconds (idling was going down slowly to 1.5k). then suddenly it started to go up to 4k, so i had to turn it off. ive checked the throttle cables and everything seems to be fine. i dont get any codes either. what should i do, guys? i cant think of anything. please help! it is embarrassing to be on a stop with all them cars and the bike revving like crazy.

btw i used this pic from another forum. i've adjusted the circled part a bit (did not remove it).

 

Sounds ECU related. Did you knock off the wire for the airflow meter or CTS?

 

i'm not quite sure what you're talking about (airflow meter or CTS wire),
but you think I should replace the ECU? Can you please explain? I'm new to this..

 

No the engine computer control the idle of the bike. It gives fuel and air at idle based upon reading from the engine sensors. I haven't dug into the f4i in a while, but it has some sort of airflow meter. Not sure if its one or 4. The engine also runs hard when its cold. There is a coolant temp sensor on the head. As the coolant warm up the idle is higher. Perhaps one of these is unplugged?

 

the idling is odd after warm up, even after it gets to 150F it reaches 4k. So the idle supposed to get higher after the coolant warms up? i thought it was the other way around..
I thought that if something is unplugged the FI light would come up, but it claims to have no codes. Could you please tell me what to do? I really appreciate your time and knowledge.

 

The bike should idle high until it warms up... Mine doesn't start idling down till about 110 degrees and is at warm idle around 150 or higher. Make sure the bike is at operating temp, at least 170, before you go adjusting the idle.

A few things to check,

Is your throttle cable adjusted too tight and is pulling on the butterfly a little?

Is the area around the butterfly's dirty, possibly something is keeping them from closing all the way?

If the butterfly's are closed all the way when your having the high idle problem then it's probably the cold idle system that's f'd up.

There is what's called a wax unit that controls your fuel during cold idle. I've attached an image, sorry it's not good but it's the best I can find. the "wax unit" is circled in red, the adjustments for each cylinder are circled in blue, and the rod that connects them all is circled in green.

The was unit pulls on that rod when it's cold and lets a little extra gas into the engine, when it heats up it cuts off that gas, hence the high idle when it's cold.

I would check your throttle cable and the wax unit to make sure they're not the problem. If the butterfly's are closed all the way and the wax unit is in the closed position and you're still getting high idle then you've got some other problem, obviously. I wouldn't start by assuming there's an ECU problem.

 

it is not tight at all. as a matter of fact i gave it some slack with no positive results..

i will check that. what should i clean them with? i dont want any dirt to get to the head.

The rods circled in green are controlled by the idle ****, which i could see after taking the air box off and turning the ****. however, this does nothing when engine is running, even after it's warmed up..

would you recommend replacing the wax unit if everything else fails to work? thanks so much!

 

I believe ndf4i is correct. The WAX unit is responsible for the cold/fast idle, it's controlled by water temperature and is a mechanical piece, like the thermostat. What's interesting though, is how you can't regulate the RPM with the idle adjuster, so it seems like it may be stuck, or stripped.
That would be a good place to start. Section 5-71 in the Service Manual.

 

what is weird that the idle adjuster does make the mini-struts move, but no response while the engine is running..

 

As for cleaning the throttle valves on the throttle bodies, there are multiple products out there for that. However, the manual states that the intakes are coated with molybdenum, and that commercial carb cleaners may harm this coating. That said, I used rubbing alcohol and cotton swabs to clean mine. It's an excellent degreaser, but very mild.