I have a 928044 Hustler Super Z with a 30HP Kohler 60" Deck. The engine is not always firing on the front cylinder lately and today it has not power. Last year my employees weren't keeping the engine area as clean as they should and grass got builit up around the engine and I had to have the exhaust valve and head gasket replaced. This year they have been much more on top of their maint. of the machine but, its starting to have issues again. It is burning oil and not running correctly so I was thinking of replacing the engine myself vs. having the engine repaired agin. My question is what engine do I need and how difficult is it to replace. I would also need to find engine removal/installation directions.