Tractor Repair: MF 35 petrol, vacuum leaks, manifold gaskets

Question
Hi Arnie I have a petrol MF 35, I havent used it in about 3 years And after the big rains we have had in Australia lately pulled it out of the shed to do some slashing.
I changed the oil And it started up first go. I let it warm up but it wouldn't run with out the choke half out.
I then tried to do a bit of slashing. It went well till it got up to full running temperature and it spluttered and stopped i checked the points and they had travelled up the main stem and were not sparking nice so i changed them out and gaped them at 0.20.
I started the tractor up again and it was running nice but still needed the choke half out. I started slashing again and the tractor stopped again when it got up to full running Temp.
I then let it cool down while i went and got some fuel in a spray bottle. I started the tractor and it would only run on full choke this time i sprayed fuel around the manifold and it ran up on revs a little bit but not to much.
So i have pulled the manifold off and im going to put new gaskets in.

When i removed the gaskets they didn't look to be that damaged i am hoping the manifold is not warped.

What are your thoughts.

Kind regards
Geoff

Answer
  If it wasn't used in 3 years and if it had fuel in the tank, the old fuel would have turned stale.  Even if you recently filled the tank, any old fuel that was in it should have been drained out first because fuel will only stay fresh for a few months.  The carburetor could be gummed up from the old fuel, or there could be a restriction where the fuel comes out of the tank.  Check the flow of fuel to the carburetor.  The fuel line should run full stream.  A small dribble of fuel is not enough.  If you need to leave the choke part way out to run the tractor, it is starving for fuel or has a vacuum leak.  Changing the manifold gaskets is a good idea to make sure there are no vacuum leaks.  Be sure to put a new gasket between the carburetor and manifold also.  You could see if there is also an ignition problem by checking if there is still spark at the spark plugs when the engine stops running.  If not, possibly the coil quits working when it gets hot.
 You can check the manifold for warpage with a straight edge or have a machine shop do it, and they can resurface it if needed which may be less expensive than replacing it.