These kinds of sounds are usually easy to tell apart from normal lawn mower noises as they will often come on very suddenly for no apparent reason. Symptom 1 is excessive vibrations. Troubleshooting Guide For Honda Hrc Lawn Mowers Honda Lawn Parts Blog Easier way to tell if the saft is bent remove the spark plug place mower on its side turn the blade with a srew driver and look at the center bolt If you see it turn in an oval circle then you have a bent shaft. How to tell if lawn mower crankshaft is bent . Try and GOOGLE Lawn Mower Crankshaft Straightener and you will find Youtube Ebay and all sorts of good information. Sometimes I use a big hammer or sledge hammer on the shaf. Anything that seems out of the ordinary can be an indicator of a bent crankshaft. This is a terribly expensive lawn mower repair and most of the time youre better off looking for a new mower. If the shaft is bent its not going to look right as it goes around use a glove. Joined Jan 3 2013. ...