'81 xs400 2A2 dies upon throttle

[marbar]

Hello all,
Yesterday my XS400 would idle at about 3000-4000rpms and even higher when warm. Problem was air leak in fuel hose. I found solution for this on this great site so thank you all for that.

After I got rid of the high idle issue, the bike now idles low (under 1000rpm) and dies when I turn the throttle too fast. I have to be really gentle with revving it, 3-5 seconds till it builds up to 3000rpm otherwise it will die. Once the rpm is above 3000 the engine runs fine and goes back to low idle.

I had the carbs ultrasonicly cleaned and rejeted for new air filters and exhausts. But I think they set the carbs with the air leak in fuel hose (very poor job ) and now the idle mixture screws has the plastic caps on the so I can turn them only 1/2turn which doesn't seem to make any difference for the idle speed. Is there any way how to set the idle higher? I don't want to unseal the fuel line back . I guess I will have to remove the plastic caps from idle mixture screws and try to mess with them?

Thank you for you suggestions

 

[bornIIloose]

http://www.xs400.com/forum/showthread.php?t=11048

I think you are adjusting the throttle cable adjusting screw (in between the carbs I think), not the idle screw. The idle mix is a small screw that has a metal plug over it that needs to be removed before you can adjust it (on an 81 which is what I have). Everyone says the our bikes were jetted fairly lean from stock, so they recommend 3 turns out to start I think. The link above should help. I'm just summarizing info I've read, so if anyone else has a better answer they can chime in