My 2003 400i 4x4 auto will run with choke on but dies when I switch the choke off. THought it was the air filer being dirty but after cleaning that I noticed a small crack in the exhaust pipe right where the muffler joins it. Would that caust it to do that?
I did haul butt off-road(dirt/gravel roads) for hours with the arctic cat on the trailer and the front strap broke allowing the cat to move around thus damaging the tail pipe.
Thanks,
Roger

 

Dirty pilot jet.

 

I fixed the leak. Problem still there. Got a friend that is a expert at motorcycle carbs, might give a case of bud for him to look and clean the carb for me.
Thanks,
Roger

 

Yup, classic symptom of a plugged pilot jet.
Having the "choke" on, is really a starter jet or enrichener, and as soon as the choke is off, theres no more fuel coming in. The pilot jet has the smallest hole, in the carb, and thats why it plugs first and so easily. After the carb is clean, put an inline fuel filter on it.

 

thats what popped into my head when I read the thread title


Pull the pilot jet,,,,inspect it,,blow air thru it,,,,(sometimes I even use a small strand of wire to run thru it)

could just be a grain of sand,,,or some sludge

 

Roughtly, how much should a atv shop charge to "deep Clean" a carb? Also, what carb is on an 03 400I auto 4x4 cat? By friend went on leave for a month and I prefer not to wait.

 

If you are at all mechanicly inclined, do it yourself. Its not that tough to do, and you already know what to clean, the pilot jet.
Look over these two articles, and see if you want to do it yourself.
carbclean
carb clean

 

I pulled the carb and went to my local motorcycle/atv repair shop and he cleaned it via air compressor. Charged only ten bucks. I reinstalled the carb and still doesn't run right. I upped the rpms (the hand adjuster on the carb) and ran it without the air filter for a minute. It will run now without the choke but still isn't right. Cleaning the air filter right now. I also pulled the spark plug (less than 20 miles on it...2 months old) and its totally black, alot of dry carbon telling me its too rich.
Now I lost on what to do next....
Roger

Could it be bad fuel causing this??

 

did you have them pull the pilot jet out of the carb and clean the PILOT JET?

just blowing air through the carb will not clean it.......

 

I think I do that after work monday. It runs now but just don't sound right. If really cleaning the jet don't work, I have to tow it to the dealer (2hr trip one way) on saturday.
I want to thank everyone for their help.
Roger