[angel0913]

Hello everyone, I'm currently reassembling a 400ex engine. Full Rebuild. And came across this little guy lodged in the oil port (from oil filter to oil pump) I've build many engines and have never seen this plug in an engine before. So I thought I'd reach out for help. It was blocking probably 80% of the passage. Most likely main cause of engine failure. I'd like to know if anyone has ever came across this part before, It's a solid black rubber plug with what looks like a o-ring shape around the top, but still solid. It was lodged in the oil port so I figure it belongs somewhere in the engine but don't know where. Any help is apricated. Thanks.