Need Help. '04 EX Won't Run Right.

[hotrodtba]

I bought an '04 400EX and I can't get it running right. It had been sitting for a couple years, and the carb was all gummed up. I tore it apart, cleaned everything up good, and got it running. My problem is it will start and idle fine, but stumbles and spits and sputters at about 1/8 to 1/4 throttle. I've torn the carb about countless times. I've pulled out both jets and the air mixture screw, pumped half a can of carb cleaner thru the all the passages in the carb, put fresh gas with SeaFoam in it, and still for the life of me can't get it running right. What am I missing? I am almost to the point of purchasing a new carb. Please help me. Thanks.

[CJM]

Did you stick some wire thru the pilots and main to make sure they arent clogged?

[hotrodtba]

Originally posted by CJM
Did you stick some wire thru the pilots and main to make sure they arent clogged?

I can see light thru both jets. When I first cleaned the carb, the main hole thru the length of the pilot jet was completely plugged. Generous amounts of carb cleaner got it open. I haven't been able to find any wire small enough to get thru the pilot jet. I have one that will go thru the side holes, but it won't go thru the main hole.

[CJM]

Its probably gummed up. 1/8-1/4 throttle is the pilot jet.

What size pilot is in there btw?

[hotrodtba]

Originally posted by CJM
Its probably gummed up. 1/8-1/4 throttle is the pilot jet.

What size pilot is in there btw?

Everything, bike and carb, is bone stock. So 148 main and 38 pilot. Any idea what size the hole is that goes thru the pilot jet? The fact that I have a wire that I get thru the side holes but not the main hole makes me think there is a problem. Wouldn't the main hole be bigger than the side holes? Thanks for the replies. I appreciate any help.

[CJM]

Agreed. Something seems very off if the wire fits thru the sides but not the hole itself. Can you spray carb cleaner thru the hole?

Id just replace it, infact buy yourself a 40 pilot if your motors mostly stock as the 38 is a bit lean.

What you could also do is play with the air/fuel screw on the bottom of the carb. Tighten it lightly all the way in then turn it counter clockwise 2.5 turns out

[hotrodtba]

Originally posted by CJM
Agreed. Something seems very off if the wire fits thru the sides but not the hole itself. Can you spray carb cleaner thru the hole?

Id just replace it, infact buy yourself a 40 pilot if your motors mostly stock as the 38 is a bit lean.

What you could also do is play with the air/fuel screw on the bottom of the carb. Tighten it lightly all the way in then turn it counter clockwise 2.5 turns out

Yes I can see thru it. I will say while I can see thru it, it doesn't appear to my eye to be a round hole, which makes me wonder if something is in there. Yes I can spray cleaner thru it.

I put the screw at the factory 2.25 turns out.

[Stickman400]

When you spray cleaner thorugh the pilot does it come out of the end in a fan shape? If it doesn't then it has something in it. The hole in the end of pilot is a VERY tiny hole. I don't think it's the same size or any bigger than the side holes.