Went to mow yesterday and when I pushed the throttle cable to the fastest position it would run there for a few seconds and then slowly slide back to about half throttle. Did that every time I moved it back to fast. Took the air cleaner off and watched it and I could see some part (not sure what it is called) that had a spring on it and looked similar to a vacuum connection on an old car distributor. About a week ago I cleaned and sprayed WD-40 on all the moving parts under the air cleaner. (Guess I should have left well enough alone).
Anyone have an idea about what is causing this?