Idle problems yz 250 1990

[sn00ky]

Hey everyone, havn't been on in a while....but of course here I am when I need help!!!

Yz 250 1990 2 cycle...Just rebuilt top end and running good.
Before rebuild, since I owned bike (approx 30 running hrs) the bike never wanted to idle, at all.

Now that it is rebuilt, and running strong, still nothing...atm, it is running rich, mainly because I am playing with it.

Can running rich cause it to not idle?

I have replaced Pilot - 45 / Main - 310......Needle was at pos 2 (lean) and changed to 3 with no better, just richer again.

Before rebuild, plug burned perfectly with those settings (needle @ 2)....nice and brown...but no idle of course...

Any ideas? I don't want it to idle a tank of fuel, but for a few seconds at least....and mainly for some lube when going down hills n stuff....right now I have to clutch and rev all the time...kinda annoying....

Thanks!!!!.....

[Modman]

Did you play with the air screw at all?

how about just turning the idle screw up?? That's the first thing I would do before touching anything at all.

[sn00ky]

hey there,
yes, tried idle screw, it is maxed out...and brand new...(the original was worn a bit)...and it is operating as well as i can see that it moves my barrel properly....also tried air-screw from 1/2 turn all the way to 2 1/2 turns with no luck...replaced all jets in carb....including pilot jet....adjusted needle, with appropriate adjustments in air/fuel screw...still no luck....