1990 TT250 Carb Issues
 

Hi all, new to this site so hopefully you can bear with me. I have an 1990 TT250 with the TK YDIS carb setup. The issue i have is that the bike will not idle without choke and is running very rich. Ive disassembled carb numerous times, checked float height and removed and cleaned all jets and needles. Ive checked air passages with compressed air and all seems ok. I have adjusted pilot screw from fully closed to fully removed and the bike actually runs ok with the screw out! But still wont idle and runs rich. The bike blows alot of black smoke and with the choke off seems to splutter whilst running. Is there anything i am overlooking? Would the secondary carb have any effect on idle? Adjusting the pilot screw does make it run marginally better but still very rich and smokey. Any help would be appreciated

this forum is essentially 100% xt/tt600 centric
you'll have more support posting in thumeprtalk.com IMHO

If you need the choke on to idle, youre running lean in the idle curcuit.
Its usually a partially blocked idlejet, but can alo be a very low fuel-level in the carb, and drawing in unfiltered air around the carb/carb-boots.


So it looks like you have several issues, maybe someone tried to cure it by riching up the needle or mainjets, and thats why youre also running rich at other throttlepositions.