gageebees, my lawnmover is a rotary lawnmower. The blade is a counter balance, It has to be mounted on the engine. Without it, it is very difficult to start and if it doe's start it will run rough and damage the engine. I took it to the repair shop and told them what happened, and the mechanic told me never run this engine without the blade. All I can say is $175.00 later, the engine runs like new again.
Paul