runs for 10 seconds and dies

[slomo]

I am at a loss as to what to do. If it was timing, it wouldn't run as it runs smooth for 10 sec. Plenty of gas flow and good spark

You can't have plenty of gas and spark and it not run proper. Unless you have low compression or no air. Pull the air filter for testing only and see how she runs.

 

[bertsmobile1]

As you have several carbs , if they all came with solenoids , snip one off and see if that makes a difference .
IF yes then sip a volt meter on the plug and see if it supplies battery voltage after 10 seconds
Als check the ground connection for a good ground while the engine is running .

 

[rob50]

You can't have plenty of gas and spark and it not run proper. Unless you have low compression or no air. Pull the air filter for testing only and see how she runs.

I haven't been using the air filter whiie working on it

 

[rob50]

As you have several carbs , if they all came with solenoids , snip one off and see if that makes a difference .
IF yes then sip a volt meter on the plug and see if it supplies battery voltage after 10 seconds
Als check the ground connection for a good ground while the engine is running .

There are no solenoids on this engine

 

[StarTech]

Note: This mower has the 2P70M0C engine.

If running 10 secs it does sounds like an issue with fuel delivery. Have you checked the fuel tank filter and sure the fuel line is good as if the liner is collapsing as it flow good until the tank develops a slight vacuum?

 

[Honest Abe]

Need to check fuel flow into the carb. Remove the fuel line from the carb and observe the flow of fuel coming out of the fuel line. If not a full stream then there is an obstruction preventing fuel flow. and could cause the issue that you have because it is burning fuel faster than it can refill the carb.

also keep in mind that MTD likes to hide a screen in the inlet fuel pipe that cannot be directly accessed and depending on material lodged in the screen cannot be blown out with compressed are. So may need to look hard down into the fuel inlet with a magnefying glass and check for debris, and may need both compressed air and carb cleaner to get the stuff out of the screen. That screen plugging will also cause your issues.

have you pull the fuel tank cap off and cleaned any dirt/debris that may be restricting air/fuel flow