Oil leaking from odd place

Hey guys, I've noticed oil leaking from the front bottom right hand corner of my 1982 XJ750. There is a hex head and I can't tell its purpose but even after tightening down on it, I still have a leak. I'd like to know what replacement part/gasket/other I need to pick up on my upcoming front brake rebuild. And just to put you at ease, I haven't ridden since being on the forum and learning about the dangers of old brake lines.

Here's a couple of pictures:

 

I'd be willing to bet that your leak originated elsewhere and found it's way down there. My first guess would be somewhere around the valve cover. Second guess would be from the cam chain tensioner. You'd be surprised at how far oil can travel around the outside of an engine before finally finding a spot to drip from.
Clean the oil from the engine and put some baby powder on it, run the engine and find the trail of oil...Bingo!! There's your leak!
Good luck!

 

Common problem! That leads to a major oil gallery. It always cops a hit when the bike comes down (as has yours by the looks!) I fixed mine with a little silastic on the threads

 

Yep, that's a "non maintenance" plug, there's no reason to ever remove it and it's pretty fragile. If the plug is cracked I'd replace it.

It has an o-ring on it; and both the plug and o-ring are still available from Yamaha if Len doesn't have one.

 

Thanks for posting this andrew. I have the same issue, small, but I have been meaning to ask about it for 2 years.

Other issues were priority.

Adrian, did you pull it/put it back without problems? Did the silastic replace the o ring?

 

It comes out easily. I can't remember if I replaced the o ring. The silastic fixed mine but damage varies...

 

i had the same issue on my xj900. i pulled it out and teflon taped it. hasnt leaked since ^.^

 

Thanks to all for the input. I'll check it when I get home from work today and update tonight.

 

Thanks adrian!

Excellent, plenty of that on hand! I may try to match an o-ring too.