Need advice...WR450F not running with choke off

[RAKxp]

Hey everyone,
I'm working on a 2006 WR450F. The bike will run all day with the choke on but the second you push it in, the bike automatically dies. The bike was sitting for a while so I tore down the carb and cleaned it out. No change. So I pulled it down a second time, this time more thoroughly, and still no change.

The bike is completely stock with the exception of a cut grey wire and the baffle removed. Jetting is completely stock: 165 main, 45 pilot, 50 leak, and the needle only has one position. I fiddled with the fuel screw and at three turns out, it would idle for about two seconds before it would die.

I am completely stumped and starting to think that it's a jetting issue. Can anyone give me any advice. I want to make sure it is a possibility of lean jetting before I drop $80 on a JD jetting kit. Thanks for any info!

 

[Cabot]

Any temperature changes?
And did this problem happen right after you removed the baffle?

Choke makes it run richer, so my geuss would be running to lean. But there are many people around here that could make a better geuss then me.

 

[RAKxp]

No temperature changes...the bike has always run a bit rough, but now it won't run at all off choke. When the choke is on, it runs well. I thought I had the problem pinned down to a dirty carb but I cleaned every passage and jet with carb clean and compressed air. It's too bad you can't dip these Keihin carbs.

 

[_JOE_]

Don't expect to find your answer in the JD kit. Mine only had main jets and a couple needles. It's a pilot circuit issue. Are you POSITIVE the pilot isn't clogged? Have you removed it from the carb?

 

[RAKxp]

I removed every jet, every diaphragm, everything. Cleaned and recleaned and still nothing.....

I've heard these bike were lean from the factory. Does anyone have a baseline jetting for Florida weather?

 

[Shaw520]

It's a pilot circuit issue.

+1

 

[Ol'89r]

It's a pilot circuit issue.

+2

Did you remove the pilot jet and make sure you could see daylight through the orfice in the jet? Also, remove the air/fuel screw and blow compressed air in the orfice. Make sure the air comes out of the pilot jet hole. Nine times out of ten, if your bike wont idle without the choke it is a clogged pilot jet.

 

[RAKxp]

Thanks for the advice. I'll clean the circuit again and let you all know.

 

[riot983]

Raise Idle? or is that way off?

 

[RAKxp]

Idle increase doesn't do anything. I have new jets on the way and when they come in, I'll clean the circuits one more time and let you all know.