Tractor Repair: massey35 gas dies after short while, massey ferguson 35, full stream

Question
QUESTION: I have a gas massey ferguson 35 from the 60's . It started last year to die after I ran it for 30 min. or so . I would set for a min. and crank up and run alittle while and die again . It was like it needed fuel .As time went by it would die after 15 min. of use and then to like 5 min. use . Always cranks up after setting a min. or less , just won't run for long . I just put new plugs , wires , condenser , rotar , on last week . The fuel I just drained the tank , it was bad , since it would not crank and always cranks right up  . I put a tiller on and tilled for about 5 min. and died . Set 30 sec. cranked up and ran for 20 more min. . Died 3 times during this time .The bowl will not fill if I put it on tight and then open up gas to it . Fuel does flow out of it good if left loose . Need your help please .Thanks , Bobby

ANSWER: Hello,

  Even though you can get fuel to flow out by the bowl, how fast does it flow?  You have to get a full stream out of the tank, a little dribble is not enough.  Usually the shut off valve under the tank gets dirt in it and gets partly restricted.   The shut off valve can usually be blown out with compressed air after removing it from the tank.   The flow can be checked at the carburetor also by removing the fuel line and seeing how much fuel will flow out.  Again, it has to run full stream and not just trickle out.  The fuel tank has to vent properly also, or it will starve for fuel after a while.  The carburetor float and needle valve could be sticking also. There could be an electrical problem that is causing intermittent spark to the spark plugs.  Those little neon test lights that go in the spark plug or coil wire come in handy.  You can run the tractor with the light installed, and then when the engine is starts to die you can see if there is still spark indicated by the flashing light.  A timing light can be used for this also.  My tractor would shut off occasionally and it was a bad ignition switch.

---------- FOLLOW-UP ----------

QUESTION: How big a flow of gas should come out of the fuel bowl ? If I take the fuel bowl off and put it back on with the gas shut off , no gas will come into the bowl until I loosen it . Is this to happen ? The tractor will set and run like all is ok , but if I till it will die pretty quickly. It will crank up 30 sec. later , but usually will not go long and die again . Any idea where I should start ? Thanks for your help .

Answer
Hello,

  I will try to clarify my previous answer. Don't worry about the bowl not filling up until you loosen it, that's just trapped air in the bowl and is normal.  What you need to be concerned about is how much fuel will flow out with the bowl removed and the valve turned on.  The inlet holes should allow a full stream to run out, not just a small dribble.  Siphon or pump the fuel out of the tank, unscrew the shut off valve out of the tank and clean it out with compressed air.  Disassemble the valve if necessary to get out all the dirt, bugs, hay, rust, paint chips, sand, unidentified foreign objects, etc. that accumulate in these valves.  Sometimes it's possible to see what's plugging it by looking in the tank with a flashlight, but it still has to be removed to do a decent job of cleaning it out.  Flush the tank out before reinstalling the valve if necessary, or you will be doing it again later.

         Arnie