Bobcat 742 - Runs fine for a while and then dies/needs choke to run

[VAFarmUse]

Ok, so I have a 742 with the Ford gas engine. Recently I have added new plugs, wires, cap, rotor, points and condenser. I have been having an issue where it will be running fine for 20-30 minutes, and then after a while, it will start sputtering and die. Then, it will only start and run rough IF I have the choke wide open. It seems to start running weak/sputter if you put it under stress, and then if i momentarily back off the choke to where its about to die and then open it up again, it seems to breathe more life into it for about 5-10 seconds until it is back to running rough. Lately, I have been digging stumps/small trees with a stump bucket, and it seems when I am rocking the machine pretty hard, this is when it appears to all go downhill. I was thinking it may be a fuel delivery issue, as I have a filter on the line coming out of the fuel tank, and sometimes it appears as though im not getting fuel there, and then I pull the hose and either there is back pressure from the engine keeping the fuel from running or there is possibly some crud in the tank that is stopping it up (which has me thinking about why it happens when I am digging stumps and really rocking the machine back and forth). Today, it seemed as though there wasnt any fuel delivery issue, since my filter was still full, as I checked it after it sputtered and died. I also thought it could be the fuel pump going bad, but i recently put a new battery in the machine and it seemed to be running pretty strong (both pump and engine). It does do a little bit of very light backfiring while it is running, but I think that would be due to the fact it could likely use a carb adjustment/cleaning. Most of the time i can seemingly fix this issue by pulling the fuel line around the filter or down by the pump and letting gas run for a second. Makes me think there is some pressure balance issue, but not sure. Maybe it builds up over the 20-30 minutes of time that it is running pretty strong and then finally it gives out? Any help or insight into what I should be looking for would be appreciated. Thanks,

 

[walio123]

It sounds like a stuffy carburettor, try to clear it, do not touch its settings if you are not familiar with it. Also check the work of the solenoid at the bottom part of the carburetor, it may not work properly when it gets hot enough. I have described how this is done here http://www.skidsteerforum.com/DesktopDefault.aspx?tabid=54&frmView=ShowPost&PostID=106061 . if your lift pump is mechanical you have to pump to see if the solenoid works. If it is electrified, proceed as described. My last post on this topic is.