First place I would look would be the carbs, and fuel system.
If it a miss, you may have dislodged a bit of a crap in the fuel bowls, partly blocking a jet, or an emulsion tube. Maybe the sludge in the bottom of the tank could be partly blocking the fuel filter tap unit.
Unless you have broken or cracked an engine case I would it hard to beleive any harm was done internally. But shyte does happen.