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Bent valve stem need help


srwven

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I was mowing yesterday with my 7014 when it backfired loudly and quit. Pushed it back to the garage, checked spark and fuel. Checked compression by putting my finger on the spark plug hole and it wouldn't blow out air. So I took off the head and discovered the exhaust valve stem was bent and the valve would not seat at all. My question is could there be further problems I need to check or could this just have happened due to age/stress? There was a little leak in the muffler but not enough to burn the valve up, I don't think.
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A valve that bent almost has to have had a piece pf debris in the combustion chamber. Is your air cleaner ystem intact? If so look very carefully at the carb to make sure all of the butterfly screws etc. are in place. Sure sounds like something foriegn got in there. Ron
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Steve You can straighten the valve if you need the tractor and can't get a valve rite off. Roll the valve stem on a flat steel surface. Find the high spot and tap with a hammer. repeat untill you do not see light between stem and steel surface. Put in valve guide and check for binding. Lap the valve in and reinstall. This works I have done it. A friend installed the wrong spark plug in his 14 hp. It was on a Friday afternoon and snowing hard he needed it to clean his drive way. We called the dealer he did not have one in stock and could not get one till the following Tuesday. With nothing to lose we brought it into my shop tore it apart straightened the valve checked it in the valve guide for binding lapped it in and reinstalled it, checked for leaks with 100 lbs.air presure, turned the key and it started first crank. That was 15 years a go and it is still running strong. This & $1.00 might get you a small Coffee Maynard aka/UCD
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Well Ron turns out you were right. I looked around to see if anything was wedged in the exhaust port but nothing was there. I was going to clean up the inside of the cylinder head to put it back on and flattened against the inside right above the exhaust valve was a small screw. I was scratching my head wondering where it came from. Looked at the carb-it was the throttle valve screw! I guess it could have been worse than a bent valve though. I can't believe how these engines vibrate screws and bolts loose like they do. I am always tightening up stuff.
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