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Briggs-Fan, Small Engine Technician
Category: Small Engine
Satisfied Customers: 1264
Experience:  over 15 years experience in small engine repair, multiple certifications
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Engine ran fine 1/2 hour then sputtered, back-fired twice

Customer Question

engine ran fine for over 1/2 hour then sputtered, back-fired twice and died. Would not restart. Cooled down about 1/2 hour and restarted for about 3 minutes then sputtered, back-fired one time and died. Started fine the next morning ran five or so minutes before I shut it off.
Submitted: 2 years ago.
Category: Small Engine
Expert:  Briggs-Fan replied 2 years ago.

Hi my name is ***** ***** welcome to just answer. There's 2 things I would check for first , the coil and compression . The coil when it's bad will produce spark until it gets hot then stop which in turn kills the toy , the coil will not produce spark again until it cools off and will stop when hot again , the other thing to check is compression before starting the motor and right after it dies , a 4 cycle engine needs 60 psi of compression or higher to run and a 2 cycle needs 90 psi . So if you test it and you have 70 then run it till it dies and test it and have 55 psi , you know you have a compression issue wether it be valves or rings. And if you have no spark right after it dies you know you have a faulty coil .

Expert:  Briggs-Fan replied 2 years ago.

I know you said good spark but did you check it right after it dies

Customer: replied 2 years ago.
I checked the spark a little while after it quit, but it did cool down a little. While trying to start it right after it quit the first time it did not seem like it did not have any compression or spark. The starter seemed to be spinning the motor very easily with no other noise. After a few minutes I tried starting it again with it seeming to crack normally but not starting. I am not at home right now but I will run it until it dies and check the spark this afternoon along with the compression.
Expert:  Briggs-Fan replied 2 years ago.
Ok let me know , a engine needs spark , fuel and compression to run so I know something has to be missing once it heats up . Also check the oil to see if it's thin or smells like gas
Customer: replied 2 years ago.
oil is good and clean
Expert:  Briggs-Fan replied 2 years ago.
Ok. Let's see that you find with checking for spark and compression. The oil being good is a good thing , tells us the carb isn't allowing gas down into the crankcase