Small Engines (Lawn Mowers, etc.): Mower wont stay running, vent hole, intake hole

Question

Carb   I have a rear drive Troy Bilt 21 xp TB350 lawn mower with a B&s ready start professional motor(11p9022693B1)that is about a year old. The mower was running fine then just cut off with a puff of white smoke and would not start. The dealer said B&s would reject the warranty claim if any foreign object or bad fuel in the carb caused the problem so this is what I found. The carb is getting fuel and I have spark. I pulled the card cleaned the float, bowl, and main jet with a wire. This carb is auto start no prime or adjusting. I put it all back together and it still would not start. Then I noticed a tiny brass colored hole right where the air filter assy bolts to the carb. I did not know what this was (air intake hole?)so I tried to put a wire through the hole but it seemed to end or T off in the carb. I shot some carb cleaned through it and decided to try it. The motor started on the 1st pull. I cut grass twice and it ran ok, although the motor does surge a bit. On the third use it started surging badly then cut off again and would not start. I sprayed carb cleaner in the same hole again and it ran for about 15 minutes then cut off again??? I can make it run by spraying carb cleaner in this hole but I am not sure where it goes as it seems to dead end when I push a wire in it.I attached an image of the carb (PN796608)with a a line to the tiny hole I am talking about?

Answer
Larry
The whole that you are pointing too is a Vent hole which allows air to mix with fuel,when you spray into it you are forcing fuel into the carburetor. You may have debris clogged in the air & fuel passages sometimes it is hard to clean these out unless you completely soak the carburetor in a cleaning solution and even then they may not clear. You may have to just replace the carburetor,and the dealer is correct Briggs will not warranty carburetors for bad fuel any more as the fuel we get is really full of junk and when they sit for a while they evaporate and clog the ports.You can buy a new one for around $50.00-$59.00 online or from us at www.gbelect.net $47.50 Plus Shipping