Repairs John Deere Z425

jewisian

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My Z425 won't run. I cleaned and put a new kit in the carburetor, new spark plugs, changed the oil & filter, new fuel filter, new fuel pump, new air filter, new starter ( which is why started this project) and all it will do is sometimes start but won't keep running. When it runs it runs sluggish then dies. It ran before I changed the starter. I pulled the flywheel and reinstalled it to get to the starter. Any ideas of what to do next?
 

mechanic mark

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Engine is out of time. Pull flywheel again & make sure flywheel key is in position in crankshaft & flywheel before torquing flywheel nut. Make sure flywheel key is in good shape.
 

jewisian

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I thought that was maybe the case so I removed the nut and washer on the flywheel and the key looks to be ok. Do I need to pull the flywheel again and check the key? What would I be looking for? The key is flush with the top of the flywheel. Should it be farther down inside?

Thanks for your help :)
 

bertsmobile1

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The key is square.
The two keyways are rectangular that form a square when together.
usually I just do a visual, perfect square = OK.
When I am having probles I pull the flywheel to be doubly sure.
Up / down is immaterial , it is left right that you worry about.
Timing will also be out if the ignition coil is in the wrong position.

Check that the choke is fully off and that nothing is fouling the choke control rod preventing it from returning to the fully open position.
Nearly all chokes are spring loaded to open fully
 

jewisian

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Ok, I pulled the flywheel and the key didn't look square and I replaced it. Put everything back together and it started right up, but now I have a loud squeal. Runs good but the squeal is loud. Any ideas what that is from? Its hard to tell where its coming from. Is it possible the nut isn't torqued correctly?
 

bertsmobile1

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Check the coil is not rubbing on the flywheel.
If you smacked the flywheel with a hammer to loosen it good chance you have knocked off one of the internal magnets.
IF you are not sure it is comming from the engine , slip off both belts just to count out a belt .
 

jewisian

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This is becoming a nightmare. Today I went out and started it and it runs with the squeal and now has no power. It idles but but will not throttle up. Yesterday it ran fine except for the squeal. Am I doing something wrong installing the flywheel? I have done this before and have never had this problem. I rechecked the armature settings and they are set at .25. The specs say between .20 and .30 Where do I go from here???
 

bertsmobile1

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Is there oil in the sump ?
Did you carefully torque the flywheel or wack it on with an impact ( over tightening it )
Next is it a squeal or squeak ?
Rotating things squeal
Reciprocating things like Valves & pistons squeak
Is the starter fully disengaging the flywheel ?
 

jewisian

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What is the sump and do I check it for oil? I tightened the nut by hand as tight as I could. Could it be I'm not tightening it enough? When I removed the flywheel the last time the key was deformed or looked partially sheared. I replaced it and it started right up but squealed. And it is a squeal like to pieces of metal rubbing together??? Guess I need to get me a torque wrench??? And yes the starter is disengaging ok.
 

jewisian

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OK, I now have a torque wrench. I looked up the engine and it should be torqued at 150 lbs. I'm gonna pull the flywheel again, check the key and reinstall. I'll let you know what happens. It may be I'm not getting the nut tight enough?? Thanks again for all your help.
 
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