Farmall 400 missing

super99 · Sep 1, 2016

I have a 400 Farmall with a loader on it. It only gets used for loader work, so it doesn't get many hours on it. I replaced points, condenser and spark plugs last Dec and it started and seemed to run OK. I was trying to move some gravel the other night, and it would start missing under a load, sounded like it was running on 2 cylinders. I just had it at a fast idle and as soon as it got a load on it, it would start missing. Sometimes it would die when opening the throttle and sometimes it would miss and then come out of it. The motor is weak, it likes to foul spark plugs. I put a set of non-foulers on the plugs a few years ago and it helped a lot. I took the plugs out and cleaned them and they were all wet with fuel or oil, no sure which. I still have more to do, guess I'll buy another set of plugs and see if that helps. Any ideas?? Thanks, Chris

Janicholson · Sep 1, 2016

D-21 champions, or equivalent in AC or Autolite or Bosh. The plugs are a stop gap. If the smoke is mostly at idle and lessens when working on a continuous load it cold be just valve seals. Umbrella seals can be put on without removing the head. ask. Jim

rrlund · Sep 1, 2016

I thought it was the nature of the beast. I had a 350 with a loader that did the same thing. I ran non foulers in that one. I even tore it down and put rings in it thinking that was the problem. I put rubber seals on top of the valve guides,no help. It was still doing it when I got rid of it.
Those non foulers did as much good as anything.

rustred · Sep 1, 2016

i dont care what kind of plugs you put in an engine... if the engine does not get to operating temp and worked any plug will foul. thats where a spark plug cleaner and tester comes handy. clean and reuse them.seen many a good plug go in the garbage can. plugs were fouled in my w-30. put in to work on the disc today for 1/2 hr. pulled out the plugs and inspected them . they had a nice grey color to them , not black carbon. loader work is not making that engine work ... you can cover the front of the rad also with a round hole in the centre of the fan. that way your drawing in a nice flow of air through only the centre of rad . keep the temp needle in the high green area. might take a few experimental holes till u find the right size. ooh just thought now, not easy to get at rad on those so just cover the grill as required.

Steve@Advance · Sep 1, 2016

Check the points gap, check the distributor shaft for side play. Could be the points are closing up under different RPM. Also check the quality of the spark at the plugs, could need a set of wires, cap and rotor.

Take a look inside the non foulers, they may be carbon caked and need cleaning.

Is the air filter clean? As in the filter mesh up inside the canister... Try a test run with the filter disconnected, see if it makes a difference.

Bill in IL · Sep 2, 2016

If that 400 is as well used as you say I would also check the intake manifold gasket.

I will say my 400 is one that is tough on points. I think it's related to the oil seepage inside the distributor. Seems to be better since I put a new o ring in the distributor. I still have a pack of 99 that are the right size for an IH distributor if you need one.

RBoots · Sep 2, 2016

Sorry Chris, I couldn't help it, the first thing I thought was, "where did it go?"

Farmall 400 missing

super99

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Janicholson

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rrlund

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rustred

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Steve@Advance

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Bill in IL

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RBoots

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