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richardb

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I have a Tecumseh 20hp Vtwin, someone got to the carbs and lost some parts,ordered to new bowl's, fixed the fuel coming out the carb ,but it still runs rough,I set the valves(ohv)at .004 it seems to run better but it still is running rough but don't know what to do next. sure could use some help.
 

richardb

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I have a Tecumseh 20hp Vtwin, someone got to the carbs and lost some parts,ordered to new bowl's, fixed the fuel coming out the carb ,but it still runs rough,I set the valves(ohv)at .004 it seems to run better but it still is running rough but don't know what to do next. sure could use some help.
Sorry for the rough, The motor would run fine for about 30sec,then would start spitting gas out the carb and back firing.I ordered to new bowls and put them on,but it still would backfire,so I set the valves to.004 and that just about fixed it but still has some erratic noise from the carb's.I will try setting the valves to .004& .006? let me know what ya'll think or what's you advice. Thank in advance.
 

richardb

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Well I gave the carbs a good cleaning and the right cylinder has oil coming out but the left has next to no oil coming out.I disconnected the right cylinder and the machine ran good,but it's no the way it should be. I guess the next thing is to remove the motor and take the bottom end off and see what is going on.The carb cleaning didn't do anything to improve the performance. If anyone can suggest anything other than taking the motor off the machine,please give me your suggestion.
 

bertsmobile1

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Sound like a blown head gasket on the duff cylinder
 

upupandaway

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The behavior sounds like the intake valve is warping as it heats up being spitting back up the carb again...
A bad gasket would not cause this.

I don't know why but of the 4 briggs 12.5hp that i found over the years, they were sitting around for decent periods of times some several years.
Upon getting them up and running, all of them a valve warped on the second cutting of 1 acre after fix. Replace and no problems since. Strange - sitting around makes them go bad?!?!?!? Same behavior - runs for no more than 1min then spits back up the carb.
 

richardb

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Thanks guy's, I took the head off, and am waiting for a gasket. He said it will be a bout 2 weeks. I got 4 more mowers to play with, I have 2 Craftsmen, 1 MTD,and 1 yardworks,and 1 Murry. I will probably have more questions as I try to get them going, only 3 of them don't work the way they were meant to be.
 

richardb

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Aug 26, 2017
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Thanks guy's, I took the head off, and am waiting for a gasket. He said it will be a bout 2 weeks. I got 4 more mowers to play with, I have 2 Craftsmen, 1 MTD,and 1 yardworks,and 1 Murry. I will probably have more questions as I try to get them going, only 3 of them don't work the way they were meant to be.

Well I got a new head gasket and installed it, It is 90percent better, but I'm not 100percent sure it is fixed. I don't have a lot of faith in my work. I need a link to the transmission, so I can get it to run with the speed it should have. To me the motor still has a bit of a miss?,If I can get it to run the way it is meant to go I will be content.The problem is when I am driving it you have to put it in #4 before it will go. There are 6 speed's, when it is in 6 the clutch is bouncing like crazy. and the speed doesn't really change. Any help is appreciated. Thank's ever so much to ya'll for the help.
 

bertsmobile1

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Rich,
Start a new thread
We don't know what mower the 20Hp engine is in.
So make, model number and full description of the problem.
Remember we can not see ,hear, smell or feel your mower running.
In real life we use all of these senses to make a diagnosis.
 
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