Quote from: goatI realize that this isn't going to be the most accurate thing in the world. It's a 1 wire O2 sensor. I'm not looking for perfection. If I wanted higher quality, I would have sprung for the WB sensor and built a control unit. I'm just looking for something to help me get my carbs set correctly so I stop fouling up plugs and get better gas mileage than my car.

I want to mount the O2 sensor temporarily here (pic stolen from the gallery and altered):

Is this going to make the reading from the O2 worthless? Do I need to drill a hole and weld to my header in order for the sensor to work?

The 1 wire will not work well there.  The 1-wire sensor has no heater in it.  If you're using a 1-wire I would put it in the downpipe, tune both sides the same, and drive away smiling.  

Otherwise, get a multiwire unit with it's own heater and then you can put it where you want to.

OK goat ... I welded in the sensor by the centerstand but on the outside ...  It  works fine but takes 10 mins to get warm ...  Now 1 cyl being off ... there is a way to tell ... heck I could tell when my eli went lean on 1 cyl and it's a 4 cyl bike ... You will in case of a sudden change in mix composition get a reading that is like 800 or so sorta steady and a sudden flash to 200 and then back to 800 ... If you constantly have 1 mix diferent from the other it will be 800. 200, 800, 200, 800, 200 ... always ... The sensor has like a 2 nanosecond response time ... you just have to be looking at it to see it ... However it doesn't tell you which cyl it is that went lean ... but start looking at plugs and that's apparent.
Cool.
Srinath.