62 4000 issue

rlitwin · Jul 6, 2018

Have an issue with my 62 4000. The engine was hunting while under load bush hogging...I replaced the points, condenser, cap, rotor, plugs and wires...gaped the points to .025 and set the timing to 4 degrees...Starts easily runs well, no hunting..

Now when under load the engine starts to break up and loose power under load after about 20 minutes of use. ..About 1400 RPM using a finish mower in heavy grass.. Thought it might be an ignition component failing when hot...Replaced the coil and the condenser again...Same issue..Plenty of fuel in the tank and the gas cap is venting, main fuel screw set to 3.5 turns out...When it happens if I throttle down for a minute or two the issue will go away for about another 5 minutes and then start to break up again..any other ideas?

Thanks in advance
Bob

Texasmark1 · Jul 6, 2018

Hunting governor is a result not a cause of your problem. (opinion)

If fuel level supports it, just take the cap off for a bit. Check screen at the bottom of the tank (inside) for debris. When the engine is cool, remove the
fuel line at the carb inlet and let fuel flow....good solid stream? Not as much a possibility: How's the screen in the fuel filter? Varnished up?

Any chance of old fuel in the carb that could have varnished and is hanging up your float? I hear fuel starvation problem and a moving smoking gun
which to me is crud in the line, or in a screen that sloshing fuel, or mechanical vibrations of the tractor moves it around as you mow.

No blue smoke I assume, like your oil bath air cleaner is too full or sloshing around due to rough terrain and getting oil in your engine, temporarily
fouling your plugs......

rlitwin · Jul 6, 2018

Thanks for the reply..I agree the governor is a symptom of the problem..That is why I replaced the ignition components..points were pitted and the cap and rotor were carboned up a bit.. I'll check the fuel system..It just seem strange that it happens about every 20 minutes of use under load..that is why I first though heat may be an issue with the condenser or the coil...then i figured what else ..could be the tank is not venting and it is an issue after 15 -20 minutes..used it with the gas cap loose and had the same issue...plugs are fine...no signs at all of fouling.ignition is new....oil bath cleaner checks out also..leaks some oil but doesn't burn any..I'll drain the tank, tear down and inspect the carb and verify the float height...I just figured a fuel or carb issue would not be so consistent or show signs of a problem earlier than 15-20 minutes...
Bob

Dollar Bill · Jul 7, 2018

Welcome to the forum - Glad to have you!

TM1 gave you good advice. For a warm & fuzzy, give it some choke next time it begins to surge. If it smooths out, you've confirmed a lean condition.

When my 4K was hunting, I rebuilt the carb and solved the problem - It was nasty in there.

Post back if you need help - Good luck with your project!

Texasmark1 · Jul 7, 2018

Heat and fuel on old 4cyl OHV Fords, yes sirree. I assume the muffler is intact under the left side of the cowl with the manifold under it and the exhaust pipe leading off it and down and under the left side of the tractor ..."heat source", and the shield under the gas tank is in place...... Yes/no? Keeps hot exhaust from vaporizing fuel and causing a "vapor lock".....vapor lock is when fuel boils on the way to it's destination and the density isn't adequate to support the engine's requirements.

Easy test, costs nothing: See if you can get it to do it when you are near a water hose....spray cool water on the bottom of the gas tank. If it recovers in short order.......

souNdguy · Jul 9, 2018

definately apply a little choke. you may be leaning out 15-20m in.

Texasmark1 · Jul 10, 2018

That would support the fuel density reduction due to temperature "boiling" the fuel somewhat.

62 4000 issue

rlitwin

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Texasmark1

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rlitwin

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Dollar Bill

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Texasmark1

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souNdguy

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Texasmark1

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