JD L series tries to start and backfires

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  #1  
Old 07-25-08, 08:23 AM
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JD L series tries to start and backfires

My L series John Deere quit on me yesterday. It tries to turn over but backfires instead. The spark plug looks good. I pulled the line between the fuel filter and the engine and gas flows freely through the filter. Don' know what to do next.
 
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  #2  
Old 07-25-08, 09:47 AM
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Could you post the engine model number, etc. please.
 
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Old 07-25-08, 10:02 AM
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Originally Posted by Airman View Post
Could you post the engine model number, etc. please.
It is a Kohler 17.5 in a JD L110
 
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Old 07-25-08, 10:14 AM
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We are getting closer. The engine will have a tag that has the model number and spec number on it. The numbers on this tag is what I am after.

Pull the carburetor bowl and see if it has water in it. Clean it of course.
 
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Old 07-25-08, 10:29 AM
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Originally Posted by Airman View Post
We are getting closer. The engine will have a tag that has the model number and spec number on it. The numbers on this tag is what I am after.

Pull the carburetor bowl and see if it has water in it. Clean it of course.
spec- PS 27509

model CV491S
 
  #6  
Old 07-25-08, 10:54 AM
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Install a new sparkplug, if that donít work check carburetor for water.
 
  #7  
Old 07-25-08, 10:57 AM
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Originally Posted by Airman View Post
Install a new sparkplug, if that donít work check carburetor for water.
OKay, btw it had been running fine for 45 minutes before it shut off.
 
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Old 07-25-08, 11:04 AM
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Try the plug.

Other things that can cause this symptom are timing and carburetor. As you said it had been running thats why I said plug and water in carburetor.
 
  #9  
Old 07-25-08, 11:38 AM
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Originally Posted by Airman View Post
Try the plug.

Other things that can cause this symptom are timing and carburetor. As you said it had been running thats why I said plug and water in carburetor.
thanks, the bowl was ok. I'll go out and get a new plug.
 
  #10  
Old 07-25-08, 03:12 PM
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Okay, new spark plug installed and now it backfires with renewed gusto! LOL
 
  #11  
Old 07-25-08, 03:15 PM
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Is it possible that it has to do with the pto [reverse] switch?
Or, the seat switch?
 
  #12  
Old 07-25-08, 11:39 PM
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Not likely. I don't generally tell folks to check the flywheel key on rider engines, but you might want to check yours. It does sound like the timing is off. Remove the flywheel bolt and you can see the key and verify it's condition.
 
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Old 07-26-08, 03:34 AM
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Originally Posted by cheese View Post
Not likely. I don't generally tell folks to check the flywheel key on rider engines, but you might want to check yours. It does sound like the timing is off. Remove the flywheel bolt and you can see the key and verify it's condition.
2 things;
am i supposed to know where the flywheel bolt is?

And is this something that would happen all of a sudden while mowing?
 
  #14  
Old 07-26-08, 04:40 AM
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Timing is set by the position of the flywheel, which is held in the position by a key. The key also serves as a shear device in case the engine comes to a sudden halt. As Cheese pointed out a sheared or partially sheared key is not normally associated with an engine on a riding mower. But it can and does happen, just from normal use - Murphyís Law.

Checking this key is simply the next step in troubleshooting. For someone who does this on a regular basis it is just the next logical thing to check.

If you do not know where the flywheel nut is, I suggest you take your machine in for repair. If the key checks out it only gets more complicated. To remove the flywheel nut requires an impact wrench or flywheel-holding tool and large wrench. If it is sheared, you will need a flywheel puller.

You have been take through the easy steps just as I or Cheese would do if he were working on your machine.

Good luck
 
  #15  
Old 07-26-08, 04:52 AM
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Thank you
 
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