Vented gas cap?

[cmyoung2]

BCS 850, B&S Vanguard V14. Motor runs fine for a while, then quits. Figured out it was a fuel supply issue, then realized the cap does not seem to be vented. Loosen the cap, everything is ok. I don't know if the cap is original or standard. It has an aluminum disk on a plastic post over a rubber? membrane on the inside, but there is no vent through the cap to the outside. Do I look for a different cap or just drill a small hole through the top?
BTW I did take pictures, just can't seem to figure out how to post.

 

[Looking4new]

I would look for a vented cap for it. If you keep the motor inside out of the weather when you aren't using it, then the cheapest way would be to punch a hole in the cap.

 

[bilrus61]

Check your fuel line filter first. I had a engine doing the exact same thing and replaced mine even though it looked clean and it was the issue and now it runs like a top. Mine was a Kawi but I think Briggs has the same in line fuel filter system.

 

[cmyoung2]

Finally figured out the problem. The 850 had not been used much when I got it. Changed gas cap, fuel filter, fuel lines, still would run a bit, then quit. Finally took the carb apart, somewhat gummed up, not bad, but bad enough. So after three trips inside the carb, 2 cans of carb cleaner, and two tanks of non-ethanol gas heavy with Seafoam, I think it is on the road to recovery. What was really weird was it would run better with the motor tilted down, tended to cut off when tilling and the motor was tilted up. But I think problem solved