Engine dies off choke

[QUIJ95]

Working on a friends 03'YZ250F that will quit as soon as the choke is closed. Pilot jet is clear, pilot air jet is clear, float level is on spec. (8mm) new spark plug, leak down test is good, valve clearence is good, pilot screw is open 1.8 turns, fresh fuel. All i can think of is to take the carb apart one more time and hope to find an obstruction in the idle circuit, and make sure the slide is installed correctly. Am I missing somthing here, if so, you experts out there please let me know.

[JohneB]

my 02 had the same prob. get the carb cleaned at a shop you trust, there are passages in the carb body that are very hard to clean and can easily be missed. now she purrs like a kitten

[tacotory]

get the carb cleaned at a shop you trust, there are passages in the carb body that are very hard to clean and can easily be missed.

Agreed

[QUIJ95]

Taking it to a shop is not on my option list. Thanks for the input but I am looking for somthing different. Will tear down carb. again and get back to you.

[mkporn]

make sure the plate in the front of the slide is in properly and the little ribbon O-ring is in good shape...

[William1]

Also, try a new pilot, not just a cleaned one. Make sure the slow air jet in the bell of the carb is clear too. It it is an adjustable one, be sure it is set right.

[hopkijm]

I'm having EXACTLY the same problem with my 02 WR250 it starts and idles great until you push in the cold choke even when the motor is hot. I torn down the carb a couple of times and even replaced my air screw with and after market field adjustable one. Sure would like an idea from someone out there besides taking it to the dealer

[JohneB]

did you clean the little jet on inside of body going to accelorator pump??? access it from body side. also supersoak that O w/ carb cleaner and use compressed air to clean. blow both the direction the flow naturally is and against, sometimes gunk gets caught in a slendering passage and air blowing other way jars loose. tighten and loosen air/mix screw BUT return to same postition, again to loosen gunk that can be trapped. Your friend should break bread and pay the $150-$300 shop time to get carb cleaned and tuned in right, plus if it gives you any trouble after that you can bring back to shop.

[QUIJ95]

Thanks for the replies everyone. I had to go out of town for a few weeks so I had to leave the YZ. After I finally got back to it i found the hot start valve was out of adjustment or sticking. I adjusted it, lubed it, and checked the cable for binds. Problem solved. Thanks again.