Cub 1720 Idles good then runs ruff then quit

[Markiemarc]

I have replaced the carb., fuel pump, and battery and still have this problem. When the motor is cool it will run and I can begin to cut grass I can go about 200 ft and the mower will begin to die. any suggestion?

Thanks
Markiemarc

 

[JTKub]

Mark, does the fuel filter & lines have fuel in them after she quits? Some (cheap) aftermarket fuel filters can cause starvation issues on vac/press pulse fuel pump equipped engines. You already replaced the carb & pump, so things I would suspect at this point:
1) Fuel filter
2) Plugged vent in gas cap causing a vacuum in tank.
3) Coil problem. Common to crop-up after they get hot, expand, etc.

G/luck!
Joel

 

[Markiemarc]

Last night I had some time to work on it again and I found the following. I was haveing a starvation issue but it was not one that you had suggested. I found a small obstruction in the float shut off that was not allow the float to seat, but was also not allowing gas to flow freely. Cleared this and my problem seems to have gone away.

Thanks
Mark

 

[OhioGuy]

Mark,
I've had the same problem twice on my 1872. A previous owner or shop rebuilt the carb and got real sloppy with Permatex or some other gasket product.

Both times, when I took the bowl off, I found blockage due to small particles. It's been fine for over a year.

Curt

 

[whaltiwanger]

My 1720 has done the same. First off, check the fuel float bowl. It probably has trash in it. While you are doing that, replace the fuel filter. If still not fixed, Replace the Stator.. Mine done that, and replaced the stator first, then found trash in the carb bowl, and the filter was clogged. Good Luck