I have a 100,000 BTU furnace heating a 1350 sq ft home. It is a 92.3% efficient unit. My question is, can you stop two of the orifices so it will not be so hot while the unit is running.
It only had a 75,000 old unit (20 Years old). Now it is so uncomfortable.

Most 90% furnaces should be set up to run as a two stage heat furnace

It really depends upon exactly which style of high efficiency furnace. Usually you cannot just plug off burners. I would have a professional service person check your unit on site to see what can be done. It would be foolish to try and give you a firm answer on a forum like this. To dangerous just to play with. Sorry.

As hvac1000 stated... you should by all means get a heating contractor to look at your unit. Some brands have de-rating kits that will drop the orifice size to run the unit at lower factory tested and approved BTU/hr input ratings... as well as other adjustments that have to be performed... way beyond this sites direction for advise... see a professional for your issue.