I have the idle where i want it, but when i throttle it and let off, the idle stays higher.example is resting idle 1400 rpm, after throttle 1600 rpm, just as an example. Ive been told by dealers that it is probably the pilot screw but ive replaced all orings in pilot screw, and checked all turns on it and it has no effect. Dealer also said the float level could be off, but its at 18mm. Throttle stop screw seems alright. could it be the accelarator pump diaphragm? all jets are clean.

 

it might be that the boot that goes over the brake/throttle is stoping it from going all the way back to it's normal position. my 91 250X did the same thing, all i had to do was twist the whole throttle assembly up a little bit and it worked fine.

 

will try throttle assembly tomorrow. also does anybody know where i can get a replacement carb gasket kit for the quad? i think it is a keihin 28mm.

 

Check for air leak. On the 1987 250x I use to have somehow my air intake boot split alittle on the bottom side right after I had installed a Lectron Carb. I thought it was the carb because I couldnt keep the idle adjusted ( it would idle higher after I gave it gas and then let off ). After awhile I noticed the split,put some silicone over it,adjusted my Jetting and it ran great.