O K .

Does any one know how an Oxygen Sensor works ?

So the Harley has a diagnostic function in its computer.   There is an Oxygen Sensor on both exhaust manifolds .   On my way to Oklahoma this summer the motor started running a little ruff.   Well , I tried injector cleaners , and different spark plugs.   Still runs ruff.  Fuel millage is down a little too (48-52 now --- 52-58 before).   So , the Diagnostic code thing says the rear Oxygen Sensor is running Rich.  

I pulled the rear O Sensor and mounted it loosely in the vice , then heated it (gently) with a propane torch while a Volt meter was hooked to the two wire leads.  "Zero" volts cold , I went up to .34 volt testing it with  mild heat.  

The real question is :  If I put a spacer in to back the O Sensor back out of the the exhaust flow a little --- then the sensor will produce less voltage .   So should that elevate the running rich problem ?

You know thats not a bad idea ! (switch-en  around)

I thought it might be like adjusting the Oxygen/Acetylene torch --- as in the more Oxygen = hotter flame.    Being the more Oxygen in the exhaust flow the hotter it is , but I'm only guessing about how those things actually work.

One thing for sure is : the hotter it gets the more voltage it produces .    

maybe you had the same problem I had.
the muff are burnt out and the half the baffles are clogging up the others.

There you go. Textbook example of muffler bearings going bad.

I'll see if I can hunt up the internal baffles I used , but in short they are the "tune able" ones off ebay  .  

Mufflers are 1.75" one end / 1.5" other end

Two baffles meet in the middle with a homemade connector pipe and baffles are fastened on each end as designed.

I'll take "more detailed" pictures if ya need them.  

Effective action for when : Textbook example of muffler bearings going bad  

If you could find a link,..
I found these, but they don;t look the same...
http://www.ebay.com/itm/HARLEY-SPORTSTER-CHOPPER-CAFE-RACER-TWIN-CHROME-SHORT...

Yea guys that's the same mufflers
I'm won't be home till Monday afternoon for more pictures ,  but
The original heat shield covers the 1.75" end.
The rear  mounting bracket goes to the rear foot-peg.
The front mount goes to the mid-mount peg holes
Also
I put a 1\4" bolt through the connection of: muffler-clamp , muffler , and header-pipe / all three layers , just to make sure they can't come off  .

The connector pipe is heavyer than both new mufflers put together

OK

The rear :

I welded a "L" bracket on the end of the Supplied Mounting Bar to reach the rear foot peg.   Hope the picture shows it good.  

Under the "Heat-Shield" (from the top) is a 1/4" short bolt threaded through all three layers of Muffler-clamp , Muffler , and Header Pipe   just for added insurance against muffler blowing off on the road (both front and rear).   The internal baffle is the weakest link in the chain now !  

Versey , You rode my Sportster up at Daves place for a bit ,  don't know if you noticed the vibration that was going on then --- but its all gone now !  

Don't  base your Sportster point-of-view on the way it felt then . its back to its "Old-Self" now