Craftsman LT4000 wont start

rett98

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My mower suddenly stopped while working in the yard. (Grinding noises were heard prior to the stopping) After checking the engine for leaks and cleaning various parts the mower will not turn over now unless the spark plug is removed. I charged up the battery and it is fully charged. Any suggestions as to why it turns over when the spark plug is removed???
 

bertsmobile1

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Removing the spark plug lowers the resistance to turning over .
At a guess, the grinding noise could have been the starter pawl grinding against the flywheel teeth
So start by taking off the blower housing and watching the starter when you try to crank the engine
The other possability is the ACR on the cam shaft has fallen apart so now there is no decompression .
The starters on mowers are deliberately weak so if there is no decompression most will not be able to crank the engine.
Check for decompression by removing the rocker cover and watching the rockers while turning the engine over by hand.
You should see one of them open slightly then close just before the piston is as far foreward as it goes ( TDC ) .
Each engine maker does this slightly differently so we are just giving general advice till you provide us with the make & model of the engine + its numbers.
 

rett98

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I really appreciate the help guys....I'll look at the suggestions you have made and report back.

Bertsmobile1...According to the Operators Manual my lawn mower is as follows:

Craftsman Model 917.28851 - Repair Parts Manual says 917.288512
21.0 HP 42" Mower
Electric start
Automatic Transmission.

One thing I should of mentioned is that after the mower stopped working I checked the oil and it was very low. I will complete an oil change before I try to repair it.

I'll let you know.

Again thanks for your help
 

bertsmobile1

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Thank you.
That is the mower , now what about the engine ?
Briggs
Kohler
Tecumseh
Power more
LCT
Chinese import
 

rett98

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Bertsmobile1 - it is a Briggs & Stratton engine
 

Gord Baker

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No sense checking valve lash if Grinding noises were heard.
A bearing is gone away somewhere, or other expensive part.
 

rett98

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Update:--- I had a mower expert come out and look at my machine. It has a camshaft issue (he thinks the ACR) which needs replacing. He has taken it away for repair. I'll found out the full extent of the repair once he has taken it apart for further inspection. He thinks it will be about $350 (which includes a deck leveling and mower blade sharpening)

Thanks for all the input and suggestions. They have been helpful.
 

bertsmobile1

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Sounds about right.
The ACR is a weak spot on these engines so don't go beating yourself up about it .
 
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