Chances of bent crankshaft?

[CharlieJ]

My dad hit a cement block while mowing last week and bent the blade. The blade was replaced but he says the mower vibrates more than it did before. What are some ways to check if the crank is bent?

 

[Colt45ws]

Turn it upside down and spin the blade. Watch and see if its off.

 

[Brett Miller]

She's bent. Crankshafts today are very soft. It it still cuts okay I would run it 'till she blows.

 

[rshaw125]

I thought the engines had a 'shear pin' to protect the engine. I remember years ago having to replace one.

 

[RWEST]

 Originally Posted By: Onmo'Eegusee

Turn it upside down and spin the blade (with the spark plug removed). Watch and see if its off.

Safety first!!! The shear pins usually only protect the flywheel, at least the ones I've seen/replaced (my sister used to wipe out the one on my Toro about 3X a year).

 

[JTK]

 Originally Posted By: Brett Miller

She's bent. Crankshafts today are very soft. It it still cuts okay I would run it 'till she blows.

Exactly. It doesn't matter if it's a $120 or a $800 mower. One solid whack and it's done. The only commercial pushmower I've ever seen with a "crankshaft protector" is on page #3 here: (whadda solid looking mower BTW) http://www.ingersolltractors.com/images/EastmanSpecSheets_011007LR.PDF Joel

 

[Colt45ws]

 Originally Posted By: RWEST

 Originally Posted By: Onmo'Eegusee

Turn it upside down and spin the blade (with the spark plug removed). Watch and see if its off.

Safety first!!! The shear pins usually only protect the flywheel, at least the ones I've seen/replaced (my sister used to wipe out the one on my Toro about 3X a year).

Ah yes. I was very tired last night. Will make it easier to spin it as well with no compression.

 

[Canawler]

Does it still vibrate after removing the blade and/or blade adapter? If so, its bent. My wife hit something with our Honda powered walk-behind a few years ago and bent the crank. The mower was only a couple of years old and the shape of the deck seemed to mulch better than any other mower I had ever used so I kept it around figuring I would one day fix it. Last winter, after pricing a new crank and a used Honda engine, I picked up one of the China specials at Harbor Freight for $80 (on sale for $100 and then an additional 20% coupon.) It bolted up and only required slight rerouting of cables (this engine is not a direct copy of the Honda as I have read on this sight) to get the mower back in action. It seems to run just as well as the Honda and holds a lot more gas... and it was way cheaper.