Model #'s are always useful!

What happens if you top off the gas tank? IF it runs good again, I'd replace the fuel filter.

Better check inside the engine shroud, for a mouse nest. They love to build their nest in amongst the fins, and the spark plug wire. And, that wire is their dessert. They chew off the insulation, for lunch.
Its possible, if the cooling fins are blocked off, for the engine to get too hot, with results as you describe. And, a mud wasp egg in the gas cap breather hole has been known to shut off the gas supply to the carb.

Thanks for some feedback... I will post the model number tonight. I do not have that in front of me.. Topping off the fuel tank does not help. I had just replaced the fuel filter, oil, gas, and oil filter. No luck so far.

As for nests... I will have to double check. I did try to blow everything out with a leaf blower but maybe I need to do a little more inspecting... I initially thought I had the clogged gas cap breather hole. I have run with the gas cap extremely loose, which I would think would allow air into the tank for the gas to drain. No luck there either.

Inspected for nests and chew'd spark plug cables.. No luck.. All is clean. The model number of the engine is
31p777-0299-e1

Did you actually remove the cooling shroud and clean between the fins?
The problem sounds heat related.

Also, make sure the vacuum hoses to your fuel pump are intact. Possibly, a marginal connection may "open up" slighty when warm, causing the pump to produce a bit less flow.

The cooling shroud was removed, the fins were not clogged... The flywheel fan is also all cleaned out.

I am not sure where the vacuum hoses are. I am not sure if this has a fuel pump, Maybe I am wrong, but I don't think there is one. I can find the fuel solenoid. If you are familiar with the engine, can you tell me where approximately the fuel pump is....

Thank you
Eric

Part N on page 2
http://www.briggsandstratton.com/pdf/owners_manual/100%5C276344TRI_B-Domestic.pdf

Looking at the IPL, I don't "think" you have one either. It appears the 0299 Type uses a non pump carb.

You did use the Briggs WHITE fuel filter, didn't you?

Looking a little more-
The White filter(75 micron) is typically used on engines with fuel pumps, while the Red filter (150 micron) is used on gravity fed systems.
The IPL shows the White filter for the 0299 Type??????

The white fuel filter is what came with the lawn mower and I have replaced it with the identical type. Thanks for all your help, If anything I am getting to understand and better maintian this small engine....

I am still having problems, maybe I can shed some more information. In July and August the tractor would run for about 20 mins then shut down, These are on days when its been warmer. Now that in the end of September I can get it to go for almost 1hour before shutting down. and now in October I can get it to run for almost 2 to 2 1/2 hours before it wants to chug and shut down. Its cooler now in October and the tractor has been running longer... In all cases if I let it cool down for 1/2 hour I can get it to go and cut the lawn again.... Any ideas...

Thanks
Eric

My GT500 w/25hp Kohler does this same thing. I have checked the coil after it quits, and both plugs spark, I have been advised to clean the fuel cap vent (which didn't make a difference), I have replaced the fuel filter, and fuel pump as well as the breather tube. Nothing has changed the fact that it quits after about 30-45 minutes. I have taken it to 3 different repair shops and none of them can find anything wrong with it. 2 of them suggested either mowing without the fuel cap, or drilling a bigger hole in it. I am wit's end.

gunzlingr@gmail.com

Easy fix. Mine did same thing. Fuel cap breather is toast. I drilled a tiny hole in top of fuel cap and problem was solved. I t took alot of figuring out but it did the trick