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Curtis B.
Curtis B., Technician
Category: Small Engine
Satisfied Customers: 28910
Experience:  Service manager and technician for all brands of engines with 40 + years of experience.
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I have a ride on mower with twin cylinder Briggs and Statton

Customer Question

I have a ride on mower with twin cylinder Briggs and Statton engine. After approx 20 mins work the engine dies. Changed in line fuel filter, also checked fuel tank breathing ok. If I apply some choke it will keep it going a bit longer. When cooled off a bit it will run again for a while.
Any ideas? Thanks, John
Submitted: 1 year ago.
Category: Small Engine
Expert:  Curtis B. replied 1 year ago.

Does it have the electric solenoid in the base of the carburetor? With engine cold, flip key on and off, listening for the click of the solenoid. Learn the sound, Then when engine quits, flip key on and off, listening for the click. No click, no fuel. This solenoid closes the main jet in the carburetor when it closes. Has to have 12 volts to it at all times the key is on. It may be getting hot and closing the main jet.

Customer: replied 1 year ago.
Hi Curtis, sorry for the delay rain and being away has prevented me from trying the suggestion out. Have just tried it and I can still hear the click near the carburettor when it stopped.
I can get it to fire up again with a lot of choke but it does not last and doesn't have power to run the blades. It does seem like a fuel problem.
Do you have anymore suggestions after the solenoid?
Many thanks, John
Expert:  Curtis B. replied 1 year ago.

with twin engine, I always want to check t be sure both cylinders are firing! If you can, loosen the spark plug wires and with engine idling, remove one wire at a time, engine should continue to run, if engine dies when wire is removed, the opposite cylinder is not firing. Check it for spark and compression, and if it has both, check the pushrods.

Customer: replied 1 year ago.
Hi. Tried plugs. Removing leads both cause the engine to stop. I can verify there is a powerful electric pulse going down the leads (and my hand!) Still seems to be a lack of fuel symptoms as the engine gets hot. Adding some choke can help for a short while. The engine tends to hunt when it starting to give up. Any more thoughts?
Thanks, John
Expert:  Curtis B. replied 1 year ago.

If it has spark and both cylinders are firing, do you have fuel getting to the carburetor from the fuel tank? Is this a gravity flow to carburetor, or does it have the pulse fuel pump?

Customer: replied 1 year ago.
There is a fuel pump. It has a short hose connection to one of the cylinder covers - this means it is pulse?
Thanks, John
Expert:  Curtis B. replied 1 year ago.

Yes, pulse pump, and the hose from rocker cover should have a slight pulse when cranking.

Curtis B. and other Small Engine Specialists are ready to help you
Customer: replied 1 year ago.
Hi Curtis
I stripped the pump last night. Bits of debris found in around the rubber disc valves. Cleaned up and reassembled. Will try running it again tonight to see if it has improved. This debris may also have made it into the carburettor.
I have now rated your service. Thanks for your help
Expert:  Curtis B. replied 1 year ago.

Thank you!

Customer: replied 1 year ago.
Hi Curtis,
It was the pulse pump that was at fault. When engine cuts out there is no fuel in the carb. Set up a gravity feed from the tank which allows it to run without problem provided the tank is reasonably full. Will replace pulse pump as not very expensive a new unit.
Cheers, John
Expert:  Curtis B. replied 1 year ago.

Good job! Thanks!