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John Deere L120 will not start


fast88fox's Avatar
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03-06-18, 12:31 PM   #1  
John Deere L120 will not start

It is finally warm enough to start mowing the grass here in NC and my L120 John Deere mower will not start. It was running fine when I last used it October of last year. The battery was dead to begin with and would not charge so I replaced it. Now the mower cranks but will not catch. I replaced the fuel filter and this did not help. It is a clear filter and I don't see any fuel in the filter housing. Is there an easy way to tell if the fuel pump is bad or a line is clogged? Any other suggestions would be helpful. The fuel pump appears to be a mechanical pump and not a vacuum one.

Thanks in advance for the help.

 
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aka pedro's Avatar
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03-06-18, 12:58 PM   #2  
Hello and welcome. You said that it "cranks but will not catch". Is the engine spinning, or just the starter? If the engine is spinning, is it at the speed that it should, or still sluggish? Did you clean the ends on the battery cables good? If the engine is not spinning, I would start by removing and cleaning the connections at the starter as well.

 
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03-06-18, 01:01 PM   #3  
It sounds like you did not do anything to prepare the mower to sit long term without use. So, I would suspect the gas has gone bad and may have clogged the carburetor. Try putting a teaspoon of fresh/new gas into the cylinder via the spark plug hole or by putting the gas down the throat of the carburetor then try starting. If it sputters and runs a few seconds it indicates a fuel problem and likely the carburetor is gunked up from sitting with gas in it.

No, spraying carb cleaner into the carburetor will not clean it. The carburetor should be removed, disassembled and cleaned to get to the small internal passages and orifices. If attempting this yourself make sure you take plenty of pictures before starting so you know how the linkages attach to the carb and then inside so you know how to put the carburetor back together.

 
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03-06-18, 04:59 PM   #4  
The motor spins and I cleaned off the battery terminals and connectors when I changed the battery. I'll get some starter fluid and try to start it that way tomorrow. If I have to take apart the carb and clean it I may leave that to someone that knows what they are doing. Thanks for the replies.

 
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03-06-18, 05:17 PM   #5  
Others gave good advise so I wont comment on answers already given, but in answer to your question;
Is there an easy way to tell if the fuel pump is bad or a line is clogged?
I'll tell you what I did last year when mine was clogged with trash build-up over the years. I took the fuel line off the carb & took my little air compressor & turned the pressure down low like 10 PSI & blew air through the hose to the tank. Lines clean for the rest of the mowing season. This year, at tune up, oil/filter change etc, I'm gonna take the tank off & clean it out.

Someone with more experience might comment on whether or not this is a bad idea, but personally, I didn't have any issues. Just turned the pressure way down low.

 
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03-07-18, 05:27 AM   #6  
Be very stingy with the ether (starting fluid) as it is hard on the engine. Only give it a small shot to see if the engine fires. If the engine pops, sputters or starts for a second that's all you need to know. Do NOT hose away with the ether to keep the engine running. If the engine does start, pop or sputter with the ether then I'm betting the carburetor needs cleaning. Fuel pumps can go bad but it is far more common for the carburetor to gunk up from sitting for a long time without being run.

If taking your mower or just the carburetor to someone to clean do it now. Everyone else that also just let their machine sit over winter will be taking theirs to be fixed so try to beat the spring rush so you don't have to wait weeks+ for your's to get fixed.

 
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03-07-18, 07:25 AM   #7  
Be very stingy with the ether (starting fluid) as it is hard on the engine

Don't remember where I heard this but they said to use WD-40 instead of starting fluid. Never tried it myself.

 
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