Generator with B&S 10 HP

YardMonkey

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I have a Troy Bilt 5550 generator with a 10 HP Briggs and Stratton engine. Starts on first pull, but will run for 4 or 5 minutes, gives a cough, and dies. Will start up again with one pull if I let it sit for about 5 mins. I pulled the carb bowl off (has 2 screws, not the single screw on the bottom) and cleaned it out. Shot some carb cleaning in all the holes and openings. Reassembled and did the same thing. It sound to me like it is filling the bowl, burning the fuel that is in the bowl and not filling the bowl while it is running. When it sits, it probably refills the bowl and runs through that cycle again. I am not a mechanic or tech, but would sure like some insight so I can use this thing again for the next hurricane....sure makes my wife happy when I can make the generator run and it in turn runs the fridge and small window A/C in the bedroom. Thanks in advance.....
 

kjvann

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Just a thought, check the valve clearance. When the engine heats up, the clearance could be too tight.
 

Lawnranger

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You are losing spark or fuel and you will have to determine which one. Next time the problem happens check for spark and if spark is present check fuel flow from the tank. You could have something in the tank obstructing the fuel outlet and restricting flow to the point that the carburetor bowl will fill with fuel but cannot keep up under load (possibly a plugged filter, if applicable). Engine off and cold, remove the fuel line from the carburetor and hold a clean container under the line to check the flow rate. The problem could also be the carburetor needle/float not opening far enough. There could be many possibilities but you will have to narrow it down.

Next time the problem happens and you have verified that spark is good, shoot a shot of carburetor cleaner directly in the carburetor throat (filter removed) and try starting the engine. If I understand you correctly, the engine needs to cool down before it will restart after it shuts down - this is your testing window to determine if the problem is fuel related.

Report back with your findings.
 

aandpdan

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One other thing to try, you may have a clogged vent in the fuel cap.

After you check fuel flow with the cap on, take it off and see if it improves.
 

YardMonkey

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I back tracked on recent events and this is what I have come up with....could this cause engine to run for a period of time and then shut off?

About 6 months ago, I loaned my generator to neighbor. He used it for 2 days and before he gave it back he changed the oil. He put, I believe 5W20 oil in it and I believe it calls for 30W...the engine has a oil level sensor that cuts it off if the oil level gets low. I checked the oil level and it looks okay...

Could having the wrong oil viscosity cause the engine to do what I have described?
 

Lawnranger

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It's possible but not probable. An easy fix would be to change the 5W20 out and put in 30W and test run your generator again. The oil level sensor senses oil level and as long as the sensor is working properly viscosity should not be an issue. There could be a problem with the sensor itself where it will shut off the spark but that goes back to what I previously said that you are either losing fuel or spark and will have to determine which.
 

lostinbaja

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You can run the generator with the wire pulled off the oil level sensor to see if it is the problem. All the sensor does is ground the ignition to kill the engine.
 

YardMonkey

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Thanks Rivet for the reminder to post the results of issues we have and solutions....

The cure for my issue was the Oil Level Sensor. I pulled the GRAY wire from its connection on the top of the engine block, gave it a pull and started on first crank. Ran it for an hour and it never killed.
Solution, faulty oil level sensor...Simple solution, gonna be a cheap fix, easy to get to after removal of gas tank.

Thanks for the help...
 

theoldwizard1

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It depends on the vintage of the engine !

Newer generator use a B&S OHV where the cylinder is on an angle (like half of a Vanguard vee twin, which it is).

Older generators have the cylinder mounted straight up and down. On the older ones there is a separate, external fuel pump. After a few years, the diaphragm dries out and it won't pump.

Trace the fuel line from the tank. If the line from the tank goes into a little "box" and then on to the carb, that is the fuel pump. There is a third line going to that box. That is the vacuum impulse line.

You would think that the fuel would gravity feed and it does refill the bowl when the engine is off. With the engine running, the pump is required.

There is no replacement for the pump diaphragm. The replacement pump is a generic pump. It is a totally different shape and will not bolt into the same place. Be "creative". Use longer fuel line if necessary. Mount with tie wraps if necessary.


(Guess how I know all this !) :biggrin:
 
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