83 xt 250 carb frustrations

My bike has run very rich since I picked it up this summer, it won't idle at all, despit cranking the screw in all the way. I didn't have time to mess with it, and tried my local dealer. A week later, I'm told by the mechanic that he tried everything, new needle and seat, smaller pilot jet, different float settings. Still rich, but now I have a mid range bog to boot! Extremely pissed by this. The tech thought maybe some nutball drilled out a passage or something, but I could only guess.

Am I better off getting a used carb for this thing, or keep screwing around with this one?

You made no mention of adjusting the fuel screw, only the idle screw, or inspecting the CV diaphragm, or  needle jet, or the vacuum line to the CV diaphragm.

All common causes of your symptoms.


Your mechanic is obviously out of his element.


Screw 31 is the idle, Screw 37 is the fuel screw.

Turn the fuel screw out 1.5 turns.

Turn the idle screw for approx 1800 rpms

If it idles ok, your pilot jet is fine




here's the carb I have for the 83: I think it's a simpler design, but may have one of the issues u mentioned, although the needle valve is new.


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