I have a 13.5 HP yard machine it will start and run fine untill I engage the blades and the it strart blowing black smoke out the muffler and will not hardley run.
#2
Padroo
Is the engine up to temperature and is the choke confirmed wide open?
check that you havent blown a head gasket , should be able to hear this when pressurised air is fed into cylinder when piston isxat tdc , and valve cover is off . or a fuel pump if model has one , may not be getting enough fuel , could also be a air leak at intake manifold