Have a look on the engine for the model number and post it here, that way we will know what you have and tell you the right oil for that engine. And help you with the starting problem.
What color is the spark plug is it black, then check if there is a good spark, also check carb to make sure fuel is in it, when was the carb cleaned out last. may also have something to do with ignition switch as it starts no problem with the recoil starter.