How long should my Burnham forced hot water boiler run for? It is a 65,000btu gas boiler. Running at 80.0% efficiency. Currently it is only running around 4 min at a time. It is 70 in the house and the thermostat is set at 74 and does not seem to be getting warmer

No heating tech here but until one comes along.

What type of hot water heating system, baseboard or radiators?
As long thermostat is calling for heat the boiler should only shut down for excessive temperature or excessive pressure. Excessive pressure could be the result of air in the system. Check water pressure of system. If radiators and you have bleeder valves at radiators, bleed all radiators.

Are the pipes into & out of all of the baseboard hot? Are the fins on the baseboard clean? Especially if you have pets, check both the under & tops of the fins.