I'm working on a 2004 YZ250F that a relative has picked up from someone recently. It has major idle problem's with out the choke. The carb is absolutely spotless and every passage squirts a good flow carb cleaner, especially the idle circuit. The fuel is fresh as well. This carb has a power wing plate welded in the intake side. I have tried jets ranging from 38 to 52 with no significant change in performance. I am at almost full idle with the adjuster to get it to roughly idle without the choke. Once again the pilot circuit is 100% clean. I have verified the valve clearances are good, the timing is good and leak down is good. I am stumped. Any ideas?