I hit a metal protrusion (probably a piece of an old farm implement) with my less than a year old mower(Toro with the 6.75 TQ). The motor stopped instantly and as quickly as a gunshot. Started it up and ran fine but with a vibration. I looked at the blade and it is bent (hopefully that means it absorbed some of the shock). The reason I want to run it without the blade is to see if the crankshaft is bent. Is this advisable? If not, how can I check to see if the crankshaft is bent?