Ford 3000 backfire

Hello! I have begun the journey to revive my inherited (Dad s) 1966 Ford 3000 gasser, and I m wondering where to go next to solve the backfiring problem I currently have. It has spent its life indoors, probably spent the better part of the last 10 yrs sitting.
I have both the service manual and operator manual to consult.
It ran good for the years prior to sitting.

What I ve done so far:
-Carb clean/rebuild
-Replace fuel tap on/off
-Replace spark plugs
-Replace fuel lift pump (was spitting gas from weep hole)
-Cleaned mouse nests as I found them
-Removed rotted muffler (straight pipe at the moment)

Point of interest:
-Wire from the distributor (power wire I believe?) is basically chewed thru, hanging on by a couple strands. It seems both ends have seen better days, would be best to replace this wire. Are the Pertronix igniter products that much better over the point condenser replacements?
-Vacuum line at the advance assembly came apart from the fitting. I cleaned off the fitting, inserted it back in, and just shoved the copper tube into the center. Probably should take it back out, flare the line and make it proper.
-Backfire is from the exhaust and also back thru the bottom of the carb. Gas leaks out the horn/plate on the bottom.

Next step:
-Inspect distributor cap closer, and confirm rotor rotation to also verify correct plug wire attachment. Long story short, I did not label them before removing, and need to confirm I have it correct moving forward.
-Consult like minded individuals on this forum to gain knowledge on this machine. More interested in testing/repairing it myself versus calling the mechanic.

This post was edited by steveo3000 on 03/13/2023 at 08:29 am.

Hi and welcome. Good to hear that you're reviving that old machine.

-Wire from the distributor (ground wire I believe?) is basically chewed thru, hanging on by a couple strands. Will try getting a picture later, seems like it s purpose may not be achieved

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Sounds like the wire from the points that goes from the distributor to the coil. Definitely needs to be replaced by a good wire.

-Vacuum line is not connected to the distributor, the fitting has rotted away.

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If that is the case then the diaphragm inside the vacuum advance is most likely bad as well, and they are no longer available, so it is probably best to plug the hole so more water doesn't get inside and then set the timing a little advanced for idle according to the manual. That distributor has two advance mechanisms, one is the vacuum advance and the other is a mechanical centrifugal advance that uses springs and weights in the base of the distributor. Make sure that things are fee and lubricated down there and the mechanical part of the advance system should still work, so setting it a little advanced at idle should allow it to run fairly smoothly across the rpm range.

-Inspect distributor cap closer, and confirm rotor rotation to also verify correct plug wire attachment. Long story short, I did not label them before removing, and need to confirm I have it correct moving forward.

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If it starts and runs, and the only problem is occasional backfiring, then the plug wires should be correct. If it is barely running and constantly backfiring, then two wires could be switched, but at least one is in the correct spot.

As for the backfiring itself, that could be a timing issue. You never mentioned whether you actually set the timing in addition to the other work you have done.

You made no mention of replacing the points and condenser or of at least lightly sanding or cleaning the pint tips
If the distributor lead wire is as bad as you say the coil isn t going to get much feed back from the points and condenser
Installed Pertronix ignition on a friends 3000 some years ago, the tractor fires up much better now than before

Hi Sean, thanks for all the good information. I have not investigated or adjusted any timing.

For the vacuum advance line, I do have it back assembled so as to not gather water, moisture, etc.

The backfire is constant, I need to have the throttle at least half-3/4 open for it to run. It is far from ideal. I plan to confirm the firing order at lunch today.

You re right Destroked, I have not gone any further on the distributor past taking off the cap. The cost/effort in rebuilding the points and the new ignition coil wire versus the pertronix kit is what I m weighing. Seems like a total upgrade.

I cleaned up the contacts on the cap and rotor. Much brighter especially on the rotor. Will order a new cap. Verified the rotor moves counter clockwise, so I did have the wires correct. Fired up with much improvement, not nearly the amount of smoke (if any) and backfire. Previously, I would downright stink after letting it run for the short times I did. However it s hard to get the right comparison because now the muffler is completely off. It s loud as hell.

The main contact wire from the coil to distributor is my next step. I can see that being a huge problem, and in all honesty the obvious change from sitting. It ran good before parked, and was kept indoors, so I m leaning toward easy/obvious stuff first (hence the gas related items already.)




This post was edited by steveo3000 on 03/13/2023 at 10:19 am.

If it was sitting inside a garage or barn, then a mouse could have chewed on that wire while it was sitting, so don't assume that it's not part of the problem.

(quoted from post at 18:07:11 03/13/23) If it was sitting inside a garage or barn, then a mouse could have chewed on that wire while it was sitting, so don't assume that it's not part of the problem.

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Absolutely. That makes me think it s possibly the main problem. Will report back shortly

I suggest you do as Destroked says and fix
that distributer wire and clean and regap
your points. You don't need to replace the
points unless they are pitted.
That is Always the first thing you should
do. Though the 3 cylinder Fords are a PIA
to work on the points it really isn't much
'cost/effort' to do.
I always pulled the SP wires out of the
distributer cap then completely remove the
cap from the tractor. Much easier to get to
the points that way.
If you wish to install electronic ignition
you can do that later but get it running
first before you spend a bunch of dough on
EI.

Just saw the photo of the tractor with the loader, those loader make working on the gas models so much more fun. NOT

(quoted from post at 09:35:00 03/14/23)
Just saw the photo of the tractor with the loader, those loader make working on the gas models so much more fun. NOT

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really appreciate you noticing that, because honesty it has been a challenge. Not that I haven t been able to complete, but makes it difficult. My friend suggested taking the loader off, there are only a few bolts, but I m hoping to not need to. Getting the carb off was harder than replacing the fuel lift pump.

Going to try fitting a new primary wire into todays schedule.

Made up a new primary line, installed it, and cleaned up my contacts in the process. Set the gap at high lobe to .025, I never want to do that again, just throwing that out there! Seems to run better, I let it run a little longer this time to see if it would clear up. Maybe should go longer. Let me see if I can attach a video.

[video play=false:f190354f33]https://forums.yesterdaystractors.com/videos/mvvideo103387.mp4[/video:f190354f33]

This post was edited by steveo3000 on 03/14/2023 at 01:28 pm.

Another interesting point, I did not see any gas coming out of the bottom of the carb while running. However when I turned it off, it does leak out. I m not sure if it will stop on its own, I turn the shutoff valve to stop it. I need to make a new cork gasket ring, mine popped out and ripped.

This post was edited by steveo3000 on 03/15/2023 at 04:04 am.

Nice looking tractor. I didn't see where you said you replace the old gas with fresh. Did you?
From the photo of those points, I would replace them.

(quoted from post at 14:15:44 03/15/23) Nice looking tractor. I didn't see where you said you replace the old gas with fresh. Did you?
From the photo of those points, I would replace them.

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Hi Jim, thank you for the compliment on my tractor. I did replace with fresh gas, and it is ethanol free also. I ve witnessed too many times the problem of old gas, and in recent years the problems of ethanol in regular pump fuel with these carbureted engines.

The points were missing their shine, so I gave them some love with sandpaper, it seemed to help. After maneuvering around the lift arms, trying to keep from losing a screw inside the distributor, I ordered the pertronix electronic ignition and coil.

Major update: it sure is a beautiful thing to work from home, to be able to fiddle around with my tractor on breaks. SOafter pondering about the situation of leftover fuel, and the smokiness of the exhaust, I thoughttoo much gas. But where did I go wrong, is there a way to adjust the carb?off to the service manual I went. And alas! There is not only the idle adjustment needle (air fuel screw in modern times I believe) but also a procedure for primary adjustment.

So this is what I did. Throttle barely cracked, gas turned on, adjustment needle 1 turn out from lightly seated (mine was 3/4 out previously), full chokestart up. About the same as before. So I start to fuss with the needle, half in, half out, little more throttle, choke off. Really the best spot seemed at 3/4 out.

Ok now for the good part. Came to the conclusion that it s not adjusting the fuel enough. I turn the fuel shut off valve all the way shut and see what happens. IT CAME ALIVE! Wow! Less fuel (literally moving toward none) and it ran SO MUCH BETTER! So I cracked it barely open. Then the RPM s starting going up (air fuel screw is coming back into picture. I got caught up in this game for only a few moments before hearing a loud pop backfire, then more, so I turned off the fuel and turned it off.

I plan to take another look at this closer this evening, making sure the idle speed adjustment screw is also correct per the procedure. I am not sure what to make of the involvement of the fuel shutoff part.





This post was edited by steveo3000 on 03/15/2023 at 11:53 am.

What do the exhaust gasses look like?

They are darker, and not constant dark or thick either. Somewhat hard to explain maybe. Definitely not white, or very dark/thick.