Carb issue

[Brcbd]

On a 89 70hp evinrude, what would cause the motor to choke out just under mid throttle but idle all day & run in reverse just fine?

 

[Boobie]

Lean condition in the carbs.

 

[bobbyc]

Fuel delivery problem....bad fuel pump or filter, fuel line, connector o rings. Internal or external tank ????