Broken oil drain fix

Andy L

XS400 Member
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Hi all!

First time poster, long time reader/user of info found on here. So thanks to all that partake in the sharing of the know-how!

So, the oil drain on my '79 XS400 is fairly obliterated (see attached photo). It had been JB welded by a previous owner, only i wasn't aware of that, so when i tightened the drain bolt after my first oil change to spec torque, it started a slow leak. It then completely came apart after I removed the engine to redo a few things on it over this winter.

I am looking for suggestions, but had something in mind that i wanted to throw around to see if it'd work:
  • Cut away the drain that extends out of the crankcase, and grind the area down around the hole.
  • Find a small piece of aluminum, drill it out and tap it to size for drain bolt
  • Affix said aluminum piece to the crankcase over the existing hole using aluminum brazing rod/torch (I don't actually weld).
I've already got the crankcase split, but don't want to take anything more apart than I already have if possible, and would really prefer to salvage this crankcase half.

Does this seem like a viable solution? I've pulled the oil screen out, but not sure if there are any other temperature sensitive bits buried in there anywhere.

Any thoughts are much, much appreciated.



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Mabey, if you know someone who can tig weld aluminium really well. Build it up then mill the surface level. Drill it out bigger and re tap the hole. A lot of work, expensive too. Hope you know them really well. Definatley doable though.
Thanks for taking a look! A friends' dad has a tig welder, so i am going to have a chat with him. We'll see how it goes.