Riding mower runs for about 20 mins then stops

JP98

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My Bad Boy MZ Magnum runs for about 20 mins then stops. It starts to sputter like it's running out of gas then quits. I have a full tank of gas in it. I'd let it sit for about 10 to 15 mins, start it again and the same thing happens. Runs for a bit then quits. Fuel pump? Fuel filter? Carb issue? Any suggestions where I should start? Thanks!
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Rivets

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Two things to check the next time it happens. As soon as you feel it starts to quit open the gas cap. If it continues to run, your gas cap is bad, vent plugged, and needs to be replaced. If this is not the problem, purchase an inline spark tester, and check for spark as soon as it quits. No spark coil has either a hot short or hot open and the coil needs to be replaced. Let us know what you find.
 

JP98

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Two things to check the next time it happens. As soon as you feel it starts to quit open the gas cap. If it continues to run, your gas cap is bad, vent plugged, and needs to be replaced. If this is not the problem, purchase an inline spark tester, and check for spark as soon as it quits. No spark coil has either a hot short or hot open and the coil needs to be replaced. Let us know what you find.
Awesome suggestion! I'll start with that gas cap. Easy enough to do. I did not realize gas caps go bad like that. If it is a bad gas cap, can I drill a tiny hole on it?
I'm going to go ahead and buy a spark tester online. It's cheap enough and I'll probably need it at some point anyway. Thanks for your suggestions.
 

MParr

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Does it have a Yamaha engine on it? If so, get rid of it.
 

JP98

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The next possibility is debris floating around in the fuel tank and blocking the fuel pickup tube. That or the fuel shutoff solenoid on the fuel bowl is getting hot and shutting off.
 

JP98

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The next possibility is debris floating around in the fuel tank and blocking the fuel pickup tube. That or the fuel shutoff solenoid on the fuel bowl is getting hot and shutting off.
Thanks for your suggestion. I'm going to try the gas cap trick first. I'll add this as a possible cause if it's not the gas cap and/or the ignition coil.
 

MParr

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How old is this mower?
Fuel lines deteriorate with age. They might look good on the outside but can be flaking off on the inside. Trash inside of the tank can cause the described problem. It can float around until it blocks the pickup tube. The engine shuts down and the trash falls away from the pickup tube.
 
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