# LT1000 will not crank after running into a rock



## wponder (Apr 29, 2015)

We have a Craftsman lawn mower LT1000 20HP model 917.271920. It had been running and cutting great. 

The operator was riding the mower through a gate from the back yard to behind the fence when he ran into a big flat rock that was sometimes used to hold the gate open. 

As he recalls, the blade was not engaged, and only the outside of the deck hit the rock. The blades look fine. However, the engine shut down immediately, and we have not been able to start it again.

When we turn the key, we just hear and feel a single loud thunk -- not just a click. With the transmission engaged (via rod in the rear), we feel the thunk under the hood and under the seat; when disengaged, only under the hood. The engine does not crank. 

We tried to jump with a battery booster, but still only the single thunk.

The following sums up what we know:

•	Battery is new and has well over 12V
•	We also see 12V at the solenoid and at the starter
•	Cable connections look good
•	The fuse by the solenoid is good
•	We jumped the seat switch to make sure it was not the issue
•	The mower deck moves freely up and down
•	The mower freewheels, we can push it around

What would you suggest we check next? Thanks in advance!


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## Bill Kapaun (May 8, 2007)

The starter solenoid should make a load click.
A "thunk" pretty much has to be the engine not being able to rotate when the starter motor tries to spin it.
Either internal damage or somethings messed up down by the PTO.

I'd probably disconnect the belts and then see what happens.
Maybe you'll see the problem right away.


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## jhngardner367 (Apr 5, 2011)

Look under the tractor,at the engine pulley,to see if anything jammed the drive belt.
As Bill said,remove the belts ,and see if it starts,then .
If it still does it,then the operator had it engaged,and may have bent the crankshaft.
If it stars,check the trans belt,and the deck , to see if it is jammed,or bent.


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## wponder (Apr 29, 2015)

Thanks to you and Bill. We'll remove the belt to see if that will stop the interference and let the engine crank.


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## wponder (Apr 29, 2015)

Thought I would report on the solution to the cranking thunk. Before I could make it down to take a look at the mower, a neighbor stopped by and “fixed” it.

He lifted the deflector shield on the mower deck and noticed that the vortex baffle (159770) was folded back over the discharge. After using a hack saw to cut off the bent section, the mower cranked and started with no problem.

I don’t see why a bent baffle would prevent the mower from cranking, since the blade was not engaged; but it did. The rock must have bent the baffle when the mower hit it.

Thanks for all your suggestions. We saved them for the next incident!


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