The mower started. then just quit like ran out of gas. we blew thru the gas line going into the tank. then cleaned out filter. it won't start. at first it wouldn't even drain any gas out but we could blow bubbles in the gas 1/2 tank. Finally it started draining. Started. Then quit in about 1 min. now wont start. lines are clear.

most likely when you ran out of fuel there was some debris in the tank that now is in the carb need to remove carb and clean

To start ensure that is not a carb problem, and that the engine is not chocking because of incorrect carburetor settings. The carb should also taken apart and cleaned.

Try also running the engine without fuel tank cap, if engine runs fine replace the tank cap.

if carburetor, fuel filter, tank and fuel lines are ok it may be a faulty fuel pump failing. To test the fuel pump, insert a pressure gauge tool like this in the lines out from fuel pump.

Regards.

Potential 'air lock' - try running with out fuel tank cap on
Cap should have a fine breather hole in it

It's quite possible that as you basically ran out of fuel some dirt may have passed through from the fuel tank into the fuel line and into the filter. There is alway dirt/debris in the tank. You may need to clean out the fuel pipes and replace the fuel filter. If you don't have a filter, the dirt may have blocked on of the carburettor jets, that will need to be stripped down, cleaned and replaced.

Check wiring for ground. Ensure battery is fully charged or replace. Replace spark plug. Clean or replace air filter. check oil level, all mowers have a low oil start cutoff. Bad gas? Flush out fuel tank by removing gas line, flush fresh gas thru. Reattach gas line, fill with fresh gas, always use Stabile in gas! Check fuel line for cracks and secure connection to carb. Battery should read 12.8 volts or higher. .

Check your fuel cap vent,

There will still be some fuel mix in your fuel lines and filter. Also it probably fouled your spark plug. Try changing the spark plug first, and probably buy an extra one or two to keep in case. Also either replace the fuel filter or clean it out good, oil will stick to the elements in the filter. It won't hurt anything to run a mix in a gasoline engine, just lubed things up a little extra. Let me know if you need anything else, Daniel.

Check age of gas. Cannot be more than 30 days old. Make sure to use fresh gas w/synthetic 2-cycle oil @ 40:1 ratio (1 gal.) Gas to 3.2 oz. Oil). Do not use old or stale oil/gas mixture. Always use the proper oil/gas mix. If you do not, your engine will suffer rapid, permanent damage. May need to clean or replace carburetor, fuel lines, and fuel filter.

carb is still dirty. probably with varnish from old fuel.

Have a look at these tips for troubleshooting starting problems with lawnmowers:

http://www.fixya.com/support/r9118692-lawnmower_not_starting

Hope this helps!