New Craftsman 24hp, runs fine until load, then dies after about 1 minute.

I have a 3 month old Sears Craftsman 24 hp Elite, Kohler 7000 engine. It starts fine and will run fine as long as the blades are not engaged. Once blades are engaged it will run for maybe 1 minute then stalls out. Will restart easily in about 30 seconds but will die again within a minute or so of re-engaging the blades. I can let it idle for 20 minutes or more with no issue, or drive around the yard without the blades engaged for as long as I want. Problem only occurs when blades are engaged, and then not for at least 20 seconds or longer.

Just tried again (briefly as too dark outside) w/ gas cap loosened, seemed to run longer but had to stop test due to darkness. If that proves to be the issue, how do you unplug a plugged gas cap? Odd though that a plugged vent wouldn't stall it out when running around the yard. Again, only an issue when blades are engaged.

 

It's either a plugged gas cap vent, fuel filter, or fuel line. It's getting a small trickle of fuel into the carb... enough to run with no load but once you turn the blades on, it needs a good bit more fuel and suddenly the small trickle that was marginally sufficient is now insufficient.