Fast Idle Knob, problems?

[slowngreen]

Was having my bike stall today when ever I pulled my clutch in going slow. Went to turn my idle up a little and found out the fast idle knob is already turned all the way counterclockwise. I took it out and made sure it looked good, which it did, screws in and out good. What might be causing this? If I turn it clockwise at all, the knob has to be out for it to stay running.

[slowngreen]

I removed my throttle body and cleaned it all up, which wasn't very dirty. Checked my fuel filter which only has about 6 hours on it and it was clean too. Cleaned the air box sensor as well and nothing changed. The second I push the knob in, it dies. 

[slowngreen]

Where are all my problem solvers? @Shawn_Mc @EnglertRacing 

[luckypunk]

I want to help you out but I'd be spitballin' have any luck yet? change plug?.how about clutch drag, ie does it happen in neutral? also, you in boise area?

Edited April 15, 2018 by luckypunk

[slowngreen]

I'm a few hours from Boise. Havent changed the plug, I will though and check back. It will do it in gear or in nuetral, its just like the fast idle screw does nothing and has to be all the counter clockwise to run. 

[MedicDaddy03]

Hello Slowngreen, I am also having the same problem with my 2005 crf450x. I took the carb apart and cleaned the pilot jet and then went to adjust the idle abs broke the idle adjustment. Good times! Please let me k ow of you find anything out and I will do the same. Fingers crossed it was just a plugged pilot jet.. cheers

[slowngreen]

Mines an efi, should have said that. 

Although I don't really have a problem with it running like it does since it stays running, just cant idle any higher, I just worry its a problem that will get worse and then what? No one seems to have any ideas, thats not a good sign. 

[slowngreen]

I'm at a loss with this. Checked everything I can think of. Everything clean and in spec.

 

Could it be a failing ecm? It's getting harder to start too.

If it is, will other years work on it? Like a '15? Mines a 2014. 

[Shawn_Mc]

That passage that the idle speed knob plugs or opens up is probably filthy. I've spent quite a bit of time cleaning throttle bodies. It's absolutely amazing how friggin filthy they get. Pull the throttle body off, pull the fuel injector out, pull the cold start/idle speed knob and clean the hell out of it with spray carb cleaner. Brake cleaner wont work, its the wrong base chemical.  Carb cleaner. The Gumout brand stuff seems to work the best. Dont take the TPS off unless you have the ability to reset the closed throttle voltage reference.

[slowngreen]

21 hours ago, Shawn_Mc said:

That passage that the idle speed knob plugs or opens up is probably filthy. I've spent quite a bit of time cleaning throttle bodies. It's absolutely amazing how friggin filthy they get. Pull the throttle body off, pull the fuel injector out, pull the cold start/idle speed knob and clean the hell out of it with spray carb cleaner. Brake cleaner wont work, its the wrong base chemical.  Carb cleaner. The Gumout brand stuff seems to work the best. Dont take the TPS off unless you have the ability to reset the closed throttle voltage reference.

 

I went through and cleaned the throttle body and injector and new in tank filter too. It seemed to help it start for maybe a couple hours of ride time but it didn't change the problem with the high idle screw, still has to be all the way out for it to start and run. It will run fine once its started.

[Shawn_Mc]

Ok, when you say all the way out, are you pulling it out, or unscrewing it?

[slowngreen]

30 minutes ago, Shawn_Mc said:

Ok, when you say all the way out, are you pulling it out, or unscrewing it?

Both. It has to be all the way counter clockwise to idle. Any less and it won't start or if I screw it in at all after it's running it dies. I have to pull it out to start it. Although there isn't a noticeable drop in rpms when I push it back in.

[slowngreen]

Think Shawn bailed on me haha.

 

Today it will not start at all. I checked my valves again and they are right on. Dumped my gas and checked my filter again which I just replaced and it's still spotless. 

It fired a couple times but only for maybe a second.

[Shawn_Mc]

When you get it started, does it seem to run ok? Im wondering if you're not being fooled by the symptoms. Recently Ive come to find a bunch of different starting issues and symptoms are coming back to the fuel pressure by pass leaking back into the fuel tank. The pump makes enough pressure to run and run correctly for the most part once running, but while kicking, the pump isnt able to make the pressure because it only runs for a split second. And with the by pass leaking, the pressure falls off the injector and you get almost nothing past the pintle. One way to check this is to put 12V on the Red wire coming out of the condenser and ground to the chassis and then see how the bike starts. Basically, you're going to run the fuel pump full time, that will take the momentary problem away from the fuel pressure bypass on the pump and the bike should start first or second kick. Ive found this to be the case a couple times now. One bike I remapped around the issue and once I corrected the pump, I had to undo my map change because it was wildly too rich.

[slowngreen]

Just to update this, I've replaced the condenser and fuel pump assembly. It's back to running but the idle knob still needs to be all the way out.