Small Engines (Lawn Mowers, etc.): Engine Starting Problems, briggs and straton, sears craftsman

Question
I have a 2 year old Sears Craftsman lawnmower (model 917.388750) with a Briggs and Straton 6.5 HP engine.  The original gas tank was accidently cracked.  So I replaced the gas tank.  However, now I cannot get the engine to start and stay running.  It will only turn over if I prime the engine, and it will only stay running if I pump the primer about twice a second.  I have run the mower two to three times for a minute or two each time with this method.  Having the "accelerator handle" on or off seems to make no difference.  It has new gas, new oil and the air filter has been cleaned.  In fact, I kept it going for about 30 seconds by intermitently spraying carberator cleaner into the air in take.

Any suggestions?  Any idea of what I should pay to have someone fix it?


Answer
This is a symptom of a dirty carburetor.  Remove the float bowl nut on the bottom of the carburetor.  Make sure your do this somewhere safe because gas will drain out of the carburetor.  You may want to drain the tank to prevent too much drainage.

The bowl nut is brass so do not over tighten.  Re-install the bowl nut and try starting the engine.  If it still does not run, then you may have to remove the float bowl and clean it.  This can be done without removing the carb, just make sure the bowl seals to the upper o-ring when re-installing.

Let me know what happens.
Eric