Mowing 2201 D

[stone54]

I have a 2201 D , and when i was running it the other day i had a loss of power....it seems the fuel lever which was a little harder to use than the pedal...seems easy now, it don't feel the same...like it did. when im running and say go in a circle cut, it dies down....does anyone ever had or know what could be wrong?.....i was mowing....the lever is hooked up and looks like it is right, may be something inside where throttle is? need help bad.....this is a diesel....4 cylinder

Thanks....hope you can help