The carb needs adjusting. Try to give it gas by hand to see if it stalls out when the throttle is opened up. Depends on the engine there are adjusting screws on the carb, by unscrewing it a quarter turn at a time you should be able to throttle up from idle to wide open without stalling.

LOAD IS TOO MUCH FOR THE ENGINE. the trans or what ever sets up a gear ratio could be the issue or the air fuel ratio could be off.

Make sure the governor is not in a bind so it can open the throttle. By shut down, do you mean die, or lose power?

Try and let it go through a cycle without a log , The mech. might be jammed .

the engine shuts off.