Repairs Mower runs only with choke on

[LL1]

I have Cub Cadet push mower (model number 11A-18MC056 959-468). It starts up fine, but surges and eventually dies if I push the choke in. Will run with the choke on, but sounds weak, and dies if it hits any stiff resistance. Then it won't restart until I let it cool down. I replaced the carburetor (because it was leaking gas), so that is brand new.
Questions:
1. Could it be air leakage around the carburetor? What is the best way to detect and seal air leaks?
2. Is there some adjustment that needs to be made to a new carburetor to get the fuel/air mixture right?
3. Could this be caused by bad gas?

 

[ILENGINE]

Items 1 and 3 are both possible. Gaskets not sealing will cause a lean run condition. Bad gas can caught hard starting, and loose of power.

 

[LL1]

Ok. So it's not bad gas. It does the same thing with brand new premium gas in the tank. Is there a way to go about testing or fixing the seal around the carburetor, or do I just need to buy new gaskets? Is there something else that could cause this problem?

 

[LL1]

Items 1 and 3 are both possible. Gaskets not sealing will cause a lean run condition. Bad gas can caught hard starting, and loose of power.

It's not bad gas, so something else is causing it to run lean. Do you have recommendations for testing/fixing the seal around the carburetor? Is there anything else that might be causing the problem?

 

[Mikel1]

Will it keep running if you spray starting fluid thru carb when acts up or cuts off? Also have you replaced spark plug?

 

[turboawd]

assuming there is no vacuum leaks, you may need to adjust the carb. try turning the adj screws and see if that changes anything. just remember how much you turned them so that you can put back to original if needed.

 

[packardv8]

Two essential tools for diagnosing fuel supply problems are clear plastic fuel filters installed before and after the fuel pump. With the filters installed, I could see my problem was supply from the tank to the pump. That filter goes dry. Blowing back through the tank sometimes opens the flow. This last stoppage required buggering the vent in the tank cap so I could pressurize the tank to force fuel forward.

FWIW, the clear filter after the pump would have shown another Cub owner he didn't actually need a $100 new fuel pump.

Time for me to pull the tank and actually fix the problem.

jack vines