[Glockwo]

b48g onan engine starts fine but will surge,then will quit running.I had the sides off ran fine did not quit. put sides back on same problem,takes about two hours hard mowing on hot day for this to happen,will see air bubbles in fuel filter some times smell gas like it flooded but still mows.could this be vapor lock?

 

[jdjake49]

Mike,

Air bubbles in the fuel filter indicates to me that the fuel pickup line in the gas tank is bad or the fuel line is sucking air. My SWAG is that the fuel pickup line in the gas tank is shot. I have changed these on 3 of my GT's.Does the problem go away when you fill the gas tank?? I do not understand how the side panels could cause this problem, I was once wrong, but let's not talk about my wife here.

Opinions are like......... ,

George of Buford

 

[gzec]

If your 420 has the original fuel lines you need to change them including the pickups in the tank. They may be sucking air through the dry rotted lines. There is probably debris in the fuel tank also. After a couple of hours, the concentration of clean fuel declines in the tank and a piece of debris is sucked up.
After you replace the lines and clean the tank, put some seafoam in the fuel tank.

 

[knottyrope]

The side panels could be holding in some heat. My 420 on teh hoter days takes some time to crank over and puffs out black smoke like running too rich. I have since then only use it in the winter for snow throwing since it uses less oil in the winter.

430 is my summer machine.