Post carb rebuild, dies when I give it throttle

[firegugg]

I just rebuilt the carb on my 2005 CRF450X. I got it to idle smoothly but it dies when I give it the slightest bit of throttle. When the choke is pulled it runs at higher RPM, as expected and I can throttle it. I checked for any possibility of an air leak and the plug is brand new. Fuel screw is out 2x.

Any help is appreciated.

[Doc Brown]

Hard to say from here without having the bike. I can only guess, but think it is a carb related problem. What you say indicates that it dies because it does not get enough fuel and now you need to find out why. So I'd try the usual steps.

[mlatour]

What exactly was done as part of the rebuild?

OEM / genuine parts or aftermarket 'kit' etc

Carb dunked in solvent, TPS removed, etc.

[firegugg]

All balls carb rebuild. Took off the bowl and cleaned out green gunk from not running it 6 months. Replaced all O rings and gaskets, removed throttle slide and cleaned, replaced needle. All new jets, o stalled the external fuel screw. There is a hose at the top now that I'm wondering if it isn't a vent hose and I need to connect it to something. TPS stayed on, just removed thottlr cables, hot start and choke.

Edited June 4, 2019 by firegugg

[firegugg]

This is pre- re build but the 'vent is the top hose coming of the left side of this picture. Should that go somewhere?

[mlatour]

Carb vent /overflow hoses just 'vent' to atmosphere, none plug into anything else.

A shorter one usually loops around above, the rest just dump near the linkage.

 

Here's a thread I often link when FCR carb rebuilding is discussed:

 

Edited June 4, 2019 by mlatour

[firegugg]

E clip is on the 2nd position if that helps

[firegugg]

Been doing research like a crazed man. I might have messed with the accelerator pump timing screw, would that cause these symptom's?

[mlatour]

If it dies when slowly opening the throttle probably not,

but if wacking the throttle open no doubt yes.

[firegugg]

6 minutes ago, mlatour said:

If it dies when slowly opening the throttle probably not,

but if wacking the throttle open no doubt yes.

It's dying with very slow, very slight throttle. For whatever reason it will rev when under a load. (1st gear engaged, on stand) 

[mlhill]

I would recheck the pilot jet. Make sure you can see light through it. The pilot and the main overlap some so with choke on or simular circumstances it will seem to rev normally. 

 What you described tells me pilot jet clogged. Could be other issue but start there especially if you didn't look through it to see light.

[mlhill]

I may have spoke too soon. I just realized you installed new jets so the pilot jet shouldn't be restricted but it could be loose. 

 Why did you rebuild the carb?

[firegugg]

I let the bike sit for awhile and even with fuel treatment it was green goo throughout the carb. Cleaned all the surfaces, changed out all the jets and the needle. Installed an external fuel screw as well. Im testing the accelerator pump now

[Jason Curry]

If you pulled the slide.    You put the  plate with Oring upside down happens all the time      It’s number 14 in pic 

[firegugg]

If you pulled the slide.    You put the  plate with Oring upside down happens all the time      It’s number 14 in pic 

I did double check this and after pulling it again it was I stalled correctly.

[firegugg]

I took out all the jets, re blew out all the circuits, adjusted the accellerator pump and now we're good. Thanks gentlemen.