Drain Plug

[kjg1951]

I have a lehman 120 hp diesel engine... the oil is leaking out of the injection pump ... the PO had put in a drain line and I believe that that is why I am losing the oil .. What size is the screw/bolt for the bottom of the pump , where the oils drains from . thanks
Kevin
New Bern NC

[Panhdjoe]

The orignal drain plug at the bottom of the injection pump is 8mm 1.25 thread pitch (metric). The threads on mine were almost gone when we got the boat, The first time I changed the injection pump oil the threads striped complety when I reinstalled the plug. I had to drill out the threads and tap for a 1/8 npt pipe plug. To do that I removed the raw waterpump and drive, and basicly everything on that side of the engine to get a straight shot with the drill and tap. I coated the drill and tap with grease to catch the metal chips and then flushed sevral times with diesel fuel. I don't know if that is the problem on your engine on what setup was used to add a drain line, I had to crawl in alongside the engine to get a good look at that area nm my 120 Lehman. Good luck and let us know what to find.