2006 CRF250X Valves checked and within spec Previous owner had let the bike sit for 4 years, fuel drained, supposedly. Bike ran OK but would not idle and was hard to start. Found a deteriorating air filter and replaced. Replaced petcock. Would not shut off fuel flow. Replaced all three fuel lines. Rebuilt carb (Stock jets). Bike now starts and runs but can't get it to idle. The idle screw is all the way in. No more adjustment left. If you hold slight pressure on the throttle, the bike runs fine. Any ideas or thoughts would be great.