K301 Won't run under load
 

Guys:

I have this K301 in a cub 73, it was running fine, then just died a couple weeks ago. I rebuilt carb, replaced coil & condenser, new spark plug. She starts right up & runs but as I engage the blades about a minute later she dies. The 2 things I haven't replaced yet are the points & the spark plug wire.
I would appreciate your experienced input on this. No amount of carb adjustments have changed anything spent all day on it.

Fuel starvation.
Check the flow of gas thru the sediment bowl for blockage from crap in the gas tank.

If that is good, loosen your gas cap. If it runs ok, clean the air vent in the gas cap.

If the flow of fuel to the carb is good, check for a blown head gasket.

I fixed the problem bought a brand new $16 carburetor on ebay runs like a top again!