Thanks for the info.  I’m not a pro, just a diy’er. 
Do you have any opinion on an outside air kit for a Burnham boiler?  Burnham makes one, not that expensive, I just don’t know if it’d be worth while.
I realize the air shutter would have to be adjusted for afterwards.
Thanks.

I only use Field Controls direct venting kits.

yes they are expensive but they are quality. 

If the manufacturer recommends their device, use that.

I think it might be around $150 or so.
Here is a picture from the Burnham manual.
They recommend galvanized pipe-I imagine it should be insulated somehow.

Just had to throw my .02 in, seeing how I did this for a living for 35 yrs. or so....unless you are willing to buy ALL of the tools (combustion analyzer, oil pressure guage, etc.) you’re better off hiring a GOOD pro...not just any hack off of the street. Newer oil burners are touchy, require set up with instruments....I learned to do it by eye, then compare to analyzer to see how close I got.

Thanks.  I’ve heard the advice about hiring a good technician here and from others too.  They might be hard to find, just like a car mechanic, and just like them, word of mouth is probably best.  What I do have going for me is that my unit doesn’t appear too complex.  I can imagine how other heaters might be nearing the complexity of car engines, with computer controls as well.  Heck, my washer and dryer have error code readouts!

Well I have been thinking about the lean condition producing excess CO.  Assuming everything reacted completely then there shouldn’t be more than a trace of CO, but if the combustion were very lean, then it might be incomplete, like a car engine misfiring, so producing lots of unburnt and partially burnt reaction products.  Or then again the test unit might be confused by other gases into assuming there was more CO than really was there (because it would err on the side of safety i.e. false positives for CO)?