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Craftsman lawn mower with Tecumseh eng.

frogman1's Avatar

Join Date: Jun 2007
Posts: 1

06-20-07, 09:27 AM   #1  
Craftsman lawn mower with Tecumseh eng.

I have a Craftsman lawn mower thats about 4 yrs. old. I tried to start it this spring and removed blade and sharpened it. I had old gas and added new to fill it. Started the mower, it ran but made a rattling or ratchet noise which quieted down after about 20 min. I finished the lawn, and in about an hour I shut it of and then I tried to restart it to see if the noise had gone away. It started and made the same noise, so I shut it off. I tried to restart again and it pulled the cord our of my hand and it did this four or five times in trying to start it. I pulled the engine apart and found the flywheel key sheared so I replaced the key and tried to restart and it did the same thing, pulling the cord our of my hand. I took it apart again and found the key sheared again.I called a lawn mower place and they said it could be the water in the carborator, so I rebuilt the cargorator and because of week sp0ark I replaced the solid state module also did a compression test and obtained 90 psi and also added new spark plug and completely changed the gas. I tried to start it again and it ran again for 30 sec. and making the same noise and died. Upon trying to start it, it again pulled the cord out of my hand. I have not done anything with valve adjustments, but this is all I have left to try. Do you think there could be anything wrong with the valves? I would appreciate ANY HELP, I am completely stumped!!!!

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jsouth's Avatar

Join Date: Jul 2005
Posts: 205

06-20-07, 07:20 PM   #2  
Did you happen to hit something like a tree root or pipe in the yard could have a bent crankshaft,or have a loose blade,turn the mower on it's side with the carb. up,and turn the blade and see if your crank is bent,before doing this disconnect the spark plug wire first,and ground it to the engine,hope this helps.


cheese's Avatar
Forum Topic Moderator

Join Date: Jul 2001
Posts: 16,567

06-21-07, 12:09 AM   #3  
There are a few things that will cause it to yank the cord out of your hand: The blade not being tight enough, the blade adapter key being sheared, allowing the blade to move independent of the shaft, and the flywheel key being sheared.

The flywheel key being sheared could also be a result of the kickback created by a loose blade. The continued shearing of the flywheel key is likely because either the original problem hasn't been solved, or the flywheel nut is not being torqued to spec.

Water in the carb would never cause this.

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