Mystery Holes; Downpipes

[CrazyCloud]

Hi Guys, I just bought a used 1980 gs850 exhaust to put on my 1978 gs750. All 4 of the down pipes have an open threaded hole towards the bottom of the pipe. It goes through both layers of the pipe. One of the pipes seems to be drilled and missing the threaded insert.
Has anyone seen this before? Any ideas on what it could be for?

[hillsy]

They're for O2 sensors.

[CrazyCloud]

That makes sense, thanks. Should I look for the missing bung at my local auto parts store then? Are they usually threaded in or friction fit? I was thinking plugging them with bolts and high temp RTV, think it will hold? Or should I weld it?

[uk gs nut]

google nutserts we use them at work often, there are cheap kits you can buy. There needs to be a correct sized tool for each nutsert.

[tkent02]

O2 sensors on a 1980 850?

[uk gs nut]

More like highway peg mount frames

[hannibal]

O2 sensors on a 1980 850?

For tuning only maybe? I doubt you'd mount pegs on the downpipes.

[CrazyCloud]

Thanks guys. Whatever they did before, they'll be plugged now.

[Crankthat]

The 02 sensors were put on by a po.
Was a way to tune.
Read a article on it for my Seca I I .
Being on the downpipes gives it away.
Some would insert the sensors only while working on bike.
Some would mount the E-bay reader on the bars and use it all the time.
Has been a long time since I have read the thread or been on that forum.

http://www.xjrider.com/viewtopic.php?t=21

[CrazyCloud]

Thanks for the info Crankthat, good stuff!