Usually, if a 240 stalls every few hundred meters and can be restarted and the the tank is under half full, the problem often is the perished rubber pickup tube in the tank. Over the years I have had this problem a few times.
Remove the pump assembly and replace the perished rubber tube with, preferably a fuel resistant tube. You can buy rubber tube from most Auto Shops for about $5.00.
Photo is of the last bit of buggered tube I pulled out.
It crumbles easily and more than likely some perished pieces have found over the years their way into the fuel line and filter. Remove the filter and run the pump long enough to make sure that the petrol and lines are clean. Catch the petrol in a suitable container. Then put on a new filter.
Have fun, happy motoring.
Laurie