# John Deere 425



## Skyhawk (May 2, 2015)

I have a JD 425 that stops running after 7 to 10 minutes, sometimes I am able to restart it and it may last for 3 to 5 minutes - After sitting for a bit it will do the same thing all over again.

New fuel filter, it gets spark and gas - radiator is working and I am out of ideas!

Anyone have any ideas as to what is causing this?


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## jhngardner367 (Apr 5, 2011)

Welcome to the forum,Skyhawk !
You may have a bad fuel cut off switch,or a defective igniter module,or if it's equipped with an oil guard,it could be dirty or bad.
it sounds more like the igniter module,from the way it is acting .


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## Skyhawk (May 2, 2015)

Apologies I could not answer, my internet went down last night - Where is this igniter module located and how can I test it?

Thanks for your input as I really appreciate it


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## jhngardner367 (Apr 5, 2011)

That,I'm not sure of. Sorry.
I do know the igniter is a small box,and it's usually behind the dash,or firewall area. As for testing,it's a CDI unit,so you would have to ask a JD tech.


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## Skyhawk (May 2, 2015)

Thanks jhngardner367


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## Country Boy (Mar 18, 2010)

Another thing to check is your fuel tank vent. Many times they are on the fuel cap. I've had it enough times where a bug will build a nest in the hole and plug it up. Mower will act exactly as you describe. What John said about the ignition could also be the issue. What I usually do with mowers acting like this is to run the mower until it dies, then crack the gas cap loose slightly and restart. If it runs fine after that, then the vent is probably plugged. If it still dies, then test the spark as soon as it dies (be careful, it'll be hot!) and see if you have a spark. No spark when hot is usually an ignition issue. Kawasaki uses the two part ignition system on many of their engines, most other brands use a one piece coil/igniter assembly.

There is one other issue I have seen is where the engine overheats and boils the fuel out of the carburetor. I doubt it would happen on a liquid cooled engine, but I've seen air cooled engines get dirty or the intake screen blocks on the flywheel and the engine ends up getting so hot that the fuel in the fuel line or carb boils off and vapor locks the system. It won't run again until it cools down and the fuel can flow again. Fuel has a very high vapor pressure, so it evaporates easily and pressurizes the container its stored in. That includes the carburetor or fuel line. The vent on the carb can bleed off that pressure during normal operation, but when it gets too hot, the fuel is vaporizing faster than the vent can get rid of it. Its like the old carbureted cars years ago on a hot summer day. You'd pull out of your garage and drive to the store and park in the sun. The sun would heat up the engine bay enough to boil the fuel out of the carb and then it wouldn't start when you'd go to leave. Happened a few times on my grandma's 1974 Dodge Dart.


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## jhngardner367 (Apr 5, 2011)

The same thing happens on "AnnaBelle"my '85 C10 . 
Above 95*f,she'll stall,and I have to add fuel through the vent tube,to get her running,again.
The fuel just evaporates out of the carb.
If I run non-ethanol unleaded,it doesn't do it.


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## Skyhawk (May 2, 2015)

Some more great ideas everyone - I will check all of these but for now we are having a week long run of rain..

Thanks again


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