Can valve adjustment cause a lean condition?

[RideRed84]

I just got my 06 back together after taking apart the carb and cleaning it. I bought it off my buddy who bought it new in 07 and never really did much maintenance. It sat for maybe a year. I pulled the carb and cleaned it, changed the oil and filter, replaced the plug and cleaned the filter and air box. The quad runs ok but is lean and pops really bad on decel. It also doesn't like to idle for a long time and the idle fluctuates. I'm waiting on a D tool to come in for the mixture but should I check the valves as well?

[JOHNDOE83]

Well it wouldnt hurt to check the valve setting just to check it.

If it sat for a long time the carb was deffinetly gummed up, the pilot jet is the hardest to get clean, if you cant physically blow threw it, its still clogged.

Everything you described is pilot related so your on the right track, try to clean it again if you try to stick something threw it becareful, I broke more then a few pilot jets doing that. Some pilots dont have a hole to poke threw either, I cant remember if 400ex is one or not.

[300exBorg]

If I were you I would without a doubt take that carb apart and put a 40 or 42 pilot jet in there. You will be amazed how much better it will run if it has not been done already.

[RideRed84]

Thanks guys. I'm going to adjust the valves and replace the pilot jet.