Jetting

[Rw54450r]

Hey I just picked up a 2001 Kymco 50cc super fever. Been sitting for a long time. In great shape though besides a rat ate the air box and air cleaner. I put a K&N filter on it and it will only run with the air screw turned all the way in. Do I need to Jet this thing. If anybody can help me out here I appreciate it. The carburetor is absolutely clean

[Mr. Paul]

You need to remove the carburater bowl and clean the jets. They are most likely gunked up. Make sure in addition to using a cleaner, you remove and mechanically clean the small jet holes with a fine wire.  A lot of videos on Youtube on how to do this. Its a relatively easy job, and costs very little. After that I would run a little Seafoam in the fuel tank.  Did it run before you replaced the air box?

[Rw54450r]

Yes it did. The carb is clean. I just know on my dirt bikes the jet must be changed when a new filter is added. Wasnt sure about this thing

[Mr. Paul]

When you removed the air box and put on the K&N filter you increased the airflow into the engine which causes a too lean condition. You need to either put in a bigger jet or repair and reinstall the original air box. Check the spark plug to make sure the scooter is not running too lean. Hope that helps ya.