Operator's manual does not show how to adjust the carburetor. Mower engine dies when blade is engaged. Normally it will idle lower with blade engaged, but not stall.

If the carburetor needs adjusting then you have another problem, like the air filter is dirty, or you have trash in the carburetor float bowl or jets, or fuel tank. You should not have to adjust it. If trash is starving it for fuel then adjusting it will not help. You may need to rebuild it.