I have a 97 400 4x4 prairie. It has sat up a couple of months lately and would not run when I took it out of the shed. I opened up the carb and the jets had some gunk in them. Cleaned up the carb and put it back on the bike now it will not idle. If you choke it it will run but when you cut the choke off it will idle for about 5 sec then die out. I have checked the pilot screw and it is set right and if you turn up the idle set screw it will run but when you put it in gear it jumps and that is not safe. I have taken the carb apart again and replaced the spark pulg but still have the same problem. What should I do? Should I order another pilot screw? My service manual says a worn or damaged pilot screw will "prevent the engine from idling smoothly."