There has been no work done on it to my knowledge. I got it used about 2 years ago. About a year ago the check engien light came on and I went to Autozone and they hooked it up and they said then that's what it was. They told me to play with the plugs and most time that will fix it. Seem to do the trick till know. I went out and took the Breather off and messed with the Throttle and started it up, and it runs fine now with all the power its always had. So I got some carburator cleaner and I am going to spray in it.