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Curtis B.
Curtis B., Technician
Category: Small Engine
Satisfied Customers: 26059
Experience:  have worked on and around most engine models for 35 yrs./Polaris ATV expert
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My lawnmower keeps cutting off after running a few minutes.

Customer Question

My lawnmower keeps cutting off after running a few minutes. It will start off running for about 15 to 20 minutes and then it will cut off. It will crank right back up. The run time gets shorter and shorter.
Submitted: 1 year ago.
Category: Small Engine
Expert:  Curtis B. replied 1 year ago.

Model number? Rider or push model? What engine?Briggs?

Customer: replied 1 year ago.
13A2775S000. Riding mower. 420cc OHV Powermore engine.
Expert:  Curtis B. replied 1 year ago.

There is a solenoid, in the carburetor. It may be going out. It closes the main jet when it closes. That kills the engine. When you restart, it opens again, but is hot, so it runs shorter time!

Expert:  Curtis B. replied 1 year ago.

It is anti-backfire solenoid. Older engines did not use it. No good test for it!

Customer: replied 1 year ago.
I ran the mower and had my batter jump start box hooked to it and it kept running.
Expert:  Curtis B. replied 1 year ago.

Mower has to have 12 volts to the solenoid, or engine dies! It can be removed and disabled, and re-installed as a dummy for test.

Expert:  Curtis B. replied 1 year ago.

With voltage problem, is the charging system working?

Customer: replied 1 year ago.
Is that why it would run with the jump start box hooked up? If the battery is bad would this cause it to shut off after it is started?
Expert:  Curtis B. replied 1 year ago.

With voltage problem, is the charging system working?

Customer: replied 1 year ago.
My battery had went down. I jumped it and when I cut it off I had to jump it again. It seems not to be charging.
Expert:  Curtis B. replied 1 year ago.

The stator / alternator, is under the flywheel, and makes AC volts, it goes through a diode or rectifier/regulator to change to DC to charge the battery.

Expert:  Curtis B. replied 1 year ago.

With voltmeter you can test the system.

Customer: replied 1 year ago.
How would I do that?
Expert:  Curtis B. replied 1 year ago.

Start at battery . Needs to be good battery. Battery voltage should be around 12. 5 volts. Then start engine and run at full speed, voltage should increase to over 13 volts.

Expert:  Curtis B. replied 1 year ago.

If no increase, charging system is not working.

Expert:  Curtis B. replied 1 year ago.

Stator output needs to be tested. AC volts need to be above 28 volts AC. If it is, stator is good, and problem will be with diodes or regulator.

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