1963 Ford 4000 Backfiring Issues

[Bigdano]

Hi all any help would be greatly appreciated and answered with prayers.

Working on Ford 4000 my dad flipped and died on.

Hasn’t ran right since accident.

So far I’ve lined the gas tank, put a new fuel line on directly to carb, rebuilt carb, swapped with a carb from an 864 that runs great, put electronic ignition on, new ignition coil, put new spark plugs in….

It’s backfiring big time especially when under load running a shredder or after engine is warm going up a slight hill without pto engaged.

Any ideas?

 

[Btzj02]

Condolences to your dad. The first thing I would check is the firing order. It should be 1, 2, 4, 3. After all the work you did the spark plug wires may have gotten mixed up. We have all, at one time or another gotten the wires mixed up. The old time neighbor tells me if it is back firing the timing is off. Discovering why the time is off is the hard part. I am not familiar with the electronic ignition but some one will come along who is.

 

[Texasmark]

If an intake valve is open when the spark occurs part of the explosion goes back out that valve. Agree with it being a timing issue. If you are confused as to what plug goes where on the distributor cap, and you hadn't changed anything associated with the cap, and the plug wires seem to fit the distance to the associated spark plug, do this:

Unlock the distributor, run around 1k RPM, twist the dist in one direction until it starts acting up, record that position. Rotate the dist in the opposite direction until it starts acting up and record that position. Position the dist in the center of those marks and see what happens. I have had several 4 cyls. over the years and always timed them as I stated. Not real picky.

If that doesn't solve the problem then the wires aren't in the right place or you have a sticking intake valve.....the warm temp part of your problem suggests a sticking valve....as the valve diameter increases it binds. I have used Sea Foam to clear sticky rings and stuck valves. I just pour a 16 oz. can into the crankcase and run the tractor for half an hour, sitting still, at 1k RPM. Replace the oil and filter as usual and see how that goes. Has worked for me with minimum effort on my part.

Added note, if you had sticking rings too, then this treatment will loosen them up too.....may take awhile for the rings to clean up.....a little smoking is a (could be...if not worn out) clue to sticking rings but that doesn't enter into the timing problem. I recently bought a Ford 3600 that was smoking when first started. Did what I said in the oil and then with my new oil and filter, added 2 oz. of SF to the "fuel" and in a couple of weeks the smoking had quit.

 

[Sean in PA]

a carb from an 864

I assume that was a typo and it was supposed to be 861?

 

[Bigdano]

I assume that was a typo and it was supposed to be 861?

Yes

 

[Bigdano]

If an intake valve is open when the spark occurs part of the explosion goes back out that valve. Agree with it being a timing issue. If you are confused as to what plug goes where on the distributor cap, and you hadn't changed anything associated with the cap, and the plug wires seem to fit the distance to the associated spark plug, do this:

Unlock the distributor, run around 1k RPM, twist the dist in one direction until it starts acting up, record that position. Rotate the dist in the opposite direction until it starts acting up and record that position. Position the dist in the center of those marks and see what happens. I have had several 4 cyls. over the years and always timed them as I stated. Not real picky.

If that doesn't solve the problem then the wires aren't in the right place or you have a sticking intake valve.....the warm temp part of your problem suggests a sticking valve....as the valve diameter increases it binds. I have used Sea Foam to clear sticky rings and stuck valves. I just pour a 16 oz. can into the crankcase and run the tractor for half an hour, sitting still, at 1k RPM. Replace the oil and filter as usual and see how that goes. Has worked for me with minimum effort on my part.

Added note, if you had sticking rings too, then this treatment will loosen them up too.....may take awhile for the rings to clean up.....a little smoking is a (could be...if not worn out) clue to sticking rings but that doesn't enter into the timing problem. I recently bought a Ford 3600 that was smoking when first started. Did what I said in the oil and then with my new oil and filter, added 2 oz. of SF to the "fuel" and in a couple of weeks the smoking had quit.

Thanks for the tips… the backfire is coming out of the exhaust when it gets hot. The spark plug wires are going to same cylinders as on 861 so I know firing order is correct.

Could it be a valve lash problem or a float adjustment problem in the carb?

 

[Bigdano]

Any chance someone could walk me through checking timing? I opened the sight cover last night and looks like dad made a mark with a grinder in the flywheel. I’m not a mechanic but I’m trying to learn.

 

[Bigdano]

Here’s the ground mark on flywheel

 

[Bigdano]

More marks on flywheel, notch is between these two marks. Also first time cranking a flywheel from front with a socket wrench. I have distributor unplugged so it doesn’t fire. Is it supposed to be easier vs harder than some times to rotate because it’s varying during rotation of effort it takes to advance flywheel.

 

[used red MN]

Condolences toward your self and family as well. I would not recommend for someone who sounds like they might have minimal experience with this kind of thing to time an engine by ear. Might be two late but if you play distributor “Russian Roulette” I would mark the position where it currently is. After you set it by the above method and it’s pinging like a pinball machine when under a load you have an idea of where to set it back to so you can save your motor. Did you remove the distributor to install the electronic ignition? How much did you run the tractor before the incident? if not a lot maybe it ran poorly and you just didn’t know it and the operator never informed you of the problem. I would recommend setting the valves, maybe an intake has gotten to tight. Usually the exhaust give more trouble that way.

 

[used red MN]

s it supposed to be easier vs harder than some times to rotate because it’s varying during rotation of effort it takes to advance flywheel.

Yes, I believe that is a 4 cylinder model, due to it being a 4 cycle engine two cylinder come up on compression in one crankshaft turn. At about the last 90 degrees before the piston comes up to .top dead center. that is where the most resistance to turn the crank is felt. The uneven cranking resistance is what gives the starter the varied sound when it cranks the engine. Newer vehicles particularly semi trucks have a test mode when a laptop is connected to measure the amperage the starter pulls throughout the cranking process and it can give you a rough answer of whether the compression of the cylinders is acceptable or at least how balanced they are.

 

[Bigdano]

I removed plug 1 front of engine stuck pinky in it, felt for blowing air, air quits blowing at groove mark in flywheel. Removed distributor and rotor is pointing at number 1 cylinder.

Why will the tractor not run if I put plug at rotor to number 1 2 4 3. I rotated cap and it only fires up on 4 3 1 2

 

[Bigdano]

Condolences toward your self and family as well. I would not recommend for someone who sounds like they might have minimal experience with this kind of thing to time an engine by ear. Might be two late but if you play distributor “Russian Roulette” I would mark the position where it currently is. After you set it by the above method and it’s pinging like a pinball machine when under a load you have an idea of where to set it back to so you can save your motor. Did you remove the distributor to install the electronic ignition? How much did you run the tractor before the incident? if not a lot maybe it ran poorly and you just didn’t know it and the operator never informed you of the problem. I would recommend setting the valves, maybe an intake has gotten to tight. Usually the exhaust give more trouble that way.

I have a timing light from my father I have never messed with timing after he died I bought an 841 from Texas and rebuilt it through utube videos runs like a top. I’m thinking this is potentially timing related or something where I don’t need to tear in motor so would like to verify timing if I could before I need to. Don’t know how never did it

 

[LarryMaine]

Based on your questions, one of the first things to do is to pick up the service manual for this tractor. These are readily available on-line, and although it may not explain what to do to prevent backfiring, it will give you the OEM way to adjust the timing, and to adjust the carb, which are the first two things any of us would check. It really only gets complicated if you do these two things but it continues to backfire, then it could be a worn distributor, or a few other things, but first thing -Get the Manual.

 

[Bigdano]

Based on your questions, one of the first things to do is to pick up the service manual for this tractor. These are readily available on-line, and although it may not explain what to do to prevent backfiring, it will give you the OEM way to adjust the timing, and to adjust the carb, which are the first two things any of us would check. It really only gets complicated if you do these two things but it continues to backfire, then it could be a worn distributor, or a few other things, but first thing -Get the Manual.

I have two lol just though someone might be able to explain it simply in layman’s terms…

 

[Sean in PA]

I removed plug 1 front of engine stuck pinky in it, felt for blowing air, air quits blowing at groove mark in flywheel. Removed distributor and rotor is pointing at number 1 cylinder.

Why will the tractor not run if I put plug at rotor to number 1 2 4 3. I rotated cap and it only fires up on 4 3 1 2

4312 is the same as 1243, just staring with a different cylinder. Over multiple revolutions it is 124312431243 etc., so 4312 is just a different starting point from 1243 but the same firing order.

 

[Bigdano]

4312 is the same as 1243, just staring with a different cylinder. Over multiple revolutions it is 124312431243 etc., so 4312 is just a different starting point from 1243 but the same firing order.

Yes sir but could u help me understand why the rotor is supposed to be pointing to 1 cylinder and why the spark plug on the cap where the rotor is pointing to cylinder 1 isn’t going to 1 cylinder but cylinder 4 instead?

Also the cap has a number 1 on it but isn’t lined up to point in line with the rotor toward 1 cylinder it points the opposite direction… why?

 

[Bigdano]

Yes sir but could u help me understand why the rotor is supposed to be pointing to 1 cylinder and why the spark plug on the cap in that position isn’t going to 1 cylinder but cylinder 4 instead?

Also the cap has a number 1 on it but isn’t lined up to point in line with the rotor toward 1 cylinder it points the opposite direction… why?

Not really understanding why the rotor should point to 1 cylinder when the cap on top of the rotor has a plug that goes to cylinder 4 and the rotor cap also is labeled 1 but that doesn’t point to cylinder 1

 

[used red MN]

Not really understanding why the rotor should point to 1 cylinder when the cap on top of the rotor has a plug that goes to cylinder 4 and the rotor cap also is labeled 1 but that doesn’t point to cylinder 1

I think you just got confused or you’re not lining it up to the right mark on the flywheel. I believe you should have degree marks like 0 l l l l 5 l l l l 10… there do you see that? There may be some other mark/groove in the flywheel you mistook for the timing mark.

 

[Jim.ME]

Not really understanding why the rotor should point to 1 cylinder when the cap on top of the rotor has a plug that goes to cylinder 4 and the rotor cap also is labeled 1 but that doesn’t point to cylinder 1

When you say it only runs and starts on #4 are you basing that on the position of the rotor based on the stamped number you are looking at on the cap? Are the timing marks lined up and did you feel the air push out the plug hole of #1 with the rotor at that #4 location?

The timing marks line up in the timing window once every 360-degree rotation of the engine. The distributor is turning at 1/2 the speed of the crankshaft. Cylinder #1 lines up with the marks to fire on one rotation, it's companion cylinder #4 lines up with the same marks to fire on the next rotation of the crankshaft. Those cylinders are at the upper end of their exhaust strokes when the companion cylinder is at fire position.

As for numbers stamped (or otherwise marked on a cap by the cap manufacturer), those are only correct if the distributor was installed with the rotor positioned to match the marked location on the cap. The distributor driven gear can be installed mated with most any tooth mated to the drive gear teeth. That means the rotor could point to any location in its 360-degree sweep, that is not the same as the original location of factory installation of the distributor shaft/rotor which that cap is stamped for.

Any terminal port in the cap can be used as #1, that number on the cap is meaningless if the distributor was not installed with the rotor pointing to the right spot to match the cap. If your answers to the questions I started with your Distributor shaft was installed 180 degrees off from the marking on the cap you have and the #1 mark is now for #4 cylinder.