|
Consider your fuel pump. Could be weak and unable to pump the proper amount of fuel to keep the float bowls full. A failing pump may be able to supply the engine under light loads, but would cause the behavior you're experiencing under heavy load.
I had a 544 that had this problem once. Ran fine on the highway on level roads or on gentle hills, but trying to pull a steep hill, it would run like it had 2 spark plug wires disconnected. Turned out the little flapper (check) valves in the pump were corroded and couldn't hold full pressure when the pump was going through its cycle.
|