The fuel I use says no after run oil required for typical use so check your fuel. Remember that when you put in after run oil it will displace some of the oil already on the parts. So next time you start up your engine it is essentially lubed by the after run oil until enough fuel goes through to wash off the after run oil and replace it with regular engine oil from the fuel. So make sure your after run oil is designed not only to prevent corrosion, but also to lube a running engine. this would make me shy away from anything that isn't intended for an engine. I doubt you would get a hard failure like a seizure, but definitely increased wear on the piston, etc..