I have a '92 250X that idles very low when it's cold and dies. Once it warms up it idles fine. If I turn the idle screw in when it's cold to get a normal idle once it warms up the engine runs at 2,300-2,500 Rpm's

 

bills56f100 I have an Intertec Second Edition Manual it's not an O.E.M. manual so it doesn't cover the Honda TRX250X or any of the other Brands and Models , into very much detail as for as photo's for illistrations but it has all the specs. for a 1989 to 1990 Honda TRX250X ; but it does have the specs for the models it covers !

And i don't know if it covers a 92' model i know it cover's from a 89' up to a 90' and there might not be that much difference inbetween 89' 90' to 92' , but what it does cover is the carb brand and model ; check to see if your carb is a Keihin model number Qb29 it could be jetting Honda and all Brand's tend to set them a little on the lean side from factory to help pass EPA Emission tests !
On the one in my manual are some specs. that might help you , 1. Engine idle speed is 1300 - to 1500 rpm 2. Spark plug : NGK DR8ES-L and Nippon Denso X24ES-U Electrode Gap 0.6-0.7mm ( 0.024 - 0.o28 in. )try to set gap at 0.030 - to 0.032 in. some engine's like Honda run better with the bigger gap setting Stick ; with NGK uless you're willing to pay 10 to15 dolllars on an Indurim Platinum ( and that's for ea. plug ) !

Carburator Float height : 18.5 mm ( 0.73 in.) Ignition timing: 10 degree BTDC ( Top Dead Center ) Carb : Main Jet :#125 Idle Jet: #35 Clip Position : 3rd groove From Top And Idle Mixture Setting 2 1/2 turns out from light seat ( not to tight or you could damage the seat ) Throddle lever free play :3 - 8 mm ( 0,12 - 0.31 in. ) The idle mixture setting might be causing your problem !

Are the vakves may needing an adjustment , valve specafications are [img]i/expressions/face-icon-small-sad.gif[/img] Intake : 0.005 in. and the exhaust : 0,006 in.) this should get you started , but you might some fuel treatment in the tank ; the best i've found is Sea Foam it's a fuel cleaner/stabilizer that cleans the entire fuel system and cleans carbon deposits that build up in the ccombustion chamber and it has a drying agent in it as well to help keep condensation/ water from forming in the gas tank !
I still use stabil in fuel storage and when storing lawn and garden equpment mostly because i had a case of it left over from after i closed my shop in late 99' , but for cleaning gunk from a carb and the fuel system there's nothing better than Sea Foam for all it does to for a gas and diesel engine !

And it's safe for 2 and 4 stroke engines , you can find Sea Foam from Auto Parts Stores like Auto Zone , Advance And O'Reillys Auto Parts Stores ; I get mine at O'Reillys Auto Parts for $5.99 + tax for 16 oz. can that will treat from 8 to 25 gallons of gas or diesel !
i've seen it work with out having to remove the carb some time you can just mix some in a gas jug then pout it in your tank , and in some places where you need to spray it into the throat of the carb you can use Deep Creep ; it's the same as Sea Foam it just come in a spray can ! I highly reccomend Sea Foam and Deep Creep in over 20 yrs. in Small Engine Service and Repair , i've never found anything better ; try this and if you still have problem's let me know and i'll help as much as i can ! But no matter what the Brand Year or model Sea Foam will clean and stabilize fuel in all year makes and models when used as the direction on the can , you may have to adjust the valve's if they're off spec. but as far as cleaning the fuel system and combustion chamber there's nothing better or work's as good as the Sea Foam and Deep Creep !