Turning over, back firing, but not starting.

I hope the community here can help me solve a problem which has stumped me.

A month ago I bought a 1952 8N with a side mount distributor. It was running when I initially looked at it but it was running rough. We did some on-site adjustments of the distributor cap and fixed it just before it ran out of gas.

I haven't been able to get it to start since then.

The original owner had tried a partial 12V conversion. He had a 12 V battery and resistor. Nothing else was changed. The coil was still 6V and it has the generator and not alternator. I removed the resistor, corrected the wiring, and replaced the battery with a 6V. All connections were cleaned to be tight and bright. I replaced the spark plugs with new Autolight 437s and gapped them at 0.025. The condensor and points have been replaced. The points have been gapped at 0.025 and cleaned using Dell's dollar bill trick. The rotor has been replaced twice. We realized yesterday the cap was not the correct design so it was replaced with a new one. Voltage has been verified through the coil and we have excellent spark for all plugs. I tested using Dell's spark test.

We rotated the flywheel to the 4 degree mark and adjusted the distributor as necessary. The contact points were turned to just barely opening and then rotated back clockwise a few degrees. The plug wires were aligned with the position of the rotor. The plug wires are in the correct order - 1,2,4,3. We opened up the valve covers to verify the valves were both in the closed position at 4 degrees. We haven't done an official compression test but everything seems good when checking with our fingers.

We can't get it to start. All it does is backfire occasionally out the tailpipe. We tried jump starting it and still couldn't get it to fire up. We've added starting fluid directly into all four cylinders and it still won't fire. Just quickly backfires out of the tailpipe. At one point while doing the jump start it was back firing out of the carburetor. We have rotated the distributor shaft a few times to try and correct the timing.

The carburetor is relatively new. We pulled it and did a quick look. It looks relatively clean.

We're completely lost on what is going on, especially since we witnessed it running before paying for it.

Any thoughts?

Just to let you know, I'm a chemist and not a mechanic. I can tell you all about the chemistry of gasoline but I know virtually nothing about engines, ignitions, and timing other than what I have picked up over the past month. So, please don't assume I know even the most basic things. Thank you in advance.

Jeremy

Jeremy ,I don't know if you know it or not,but there are 2 sets of timing marks on that flywheel 180% across from each other.
Remove #1 plug and with your finger in the hole ,bump the starter till you just start to feel compression then stop.Roll engine over by hand till you see the timing marks . Lone op 4% then pull the cap and line rotor up with a cap tower,that is your #1 plug location then wire the rest 1243 in the direction the rotor turns.Replace plug and try starting.

(quoted from post at 08:51:45 03/05/21) Jeremy ,I don't know if you know it or not,but there are 2 sets of timing marks on that flywheel 180% across from each other.
Remove #1 plug and with your finger in the hole ,bump the starter till you just start to feel compression then stop.Roll engine over by hand till you see the timing marks . Lone op 4% then pull the cap and line rotor up with a cap tower,that is your #1 plug location then wire the rest 1243 in the direction the rotor turns.Replace plug and try starting.

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Thank you for this suggestion. I thought I read this somewhere which somewhat explains difficulty we were having yesterday finding the timing marks. We did this process as you described (bumping starter until feeling compression) and looked for the timing marks. We felt like we were advancing the fly wheel way too much. This is why we opened up the valve cover to look at the position of the valves when the wheel was at the 4 degree position. So here's the dumb question. If I'm on the wrong set of degree markings, will both valves still look to be in the closed position?

Jeremy

Jeremy, to answer your last question, yes I think both valves would be closed if you picked out the wrong timing mark. Right after cylinder number 4 finishes it's cycle, number 3 well start it's intake, power and exhaust cycle and then number one would have the intake valve start to open. From what your are describing it sure sounds like the timing is 180* out.

(quoted from post at 11:18:16 03/05/21) I hope the community here can help me solve a problem which has stumped me.

A month ago I bought a 1952 8N with a side mount distributor. It was running when I initially looked at it but it was running rough. [b:f630d52aca]We did some on-site adjustments of the distributor cap and fixed it[/b:f630d52aca] just before it ran out of gas. I haven't been able to get it to start since then

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Suspect timing issue

The rotor has been replaced twice

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Why the second time? Was it broken either time?

We rotated the flywheel to the 4 degree mark and adjusted the distributor as necessary. The contact points were turned to just barely opening and then rotated back clockwise a few degrees. The plug wires were aligned with the position of the rotor.

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[b:f630d52aca][i:f630d52aca]If[/i:f630d52aca][/b:f630d52aca] you were at #1 TDC of compression stroke, your rotor should have been directly under the #1 spark plug wire. Was it? If you're not sure or didn't check, follow Den's advice to be sure

(quoted from post at 11:51:45 03/05/21) Jeremy ,I don't know if you know it or not, but there are 2 sets of timing marks on that flywheel 180% across from each other.
[u:f630d52aca]Remove #1 plug and with your finger in the hole ,bump the starter till you just start to feel compression then stop[/u:f630d52aca]

Roll engine over by hand till you see the timing marks . Lone op 4% then pull the cap and line rotor up with a cap tower, that is your #1 plug location then wire the rest 1243 in the direction the rotor turns. Replace plug and try starting.

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We realized yesterday the cap was not the correct design

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What do you mean by this? How was it not correct? Did it damage the rotor?

All it does is backfire occasionally out the tailpipe...... At one point while doing the jump start it was back firing out of the carburetor.

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Out of time. Backfires out the exhaust means it is firing, but at the wrong time. it's firing while an exhaust valve is open. Out the carburetor - firing while an intake valve is open.

We have rotated the distributor shaft a few times to try and correct the timing

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How did you "correct" it? You can't guess with timing.
Follow Den's advice to get it correct.

We've added starting fluid directly into all four cylinders and it still won't fire

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Don't do this any more. You're not helping anything, and you could hurt things

The carburetor is relatively new. We pulled it and did a quick look. It looks relatively clean

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We'll get back to this once the timing issue is resolved

Any thoughts?

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Yea, timing is off. It was on at one point, as you said you saw it running, and it may be jumping time to be off, we can help determine why.
This means: you correct the timing, get the tractor to run, then it won't run again and you confirm] timing is off again.

(quoted from post at 14:06:24 03/05/21).....This is why we opened up the valve cover to look at the position of the valves when the wheel was at the 4 degree position. So here's the dumb question. If I'm on the wrong set of degree markings, will both valves still look to be in the closed position?

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Doesn't matter. Need to correct your timing and see that it stays correct.

I'll explain in simple terms but this will only confuse the matter. Go back to the beginning and get your timing correct as Den told you how.
If your 180 degrees out, your #1 piston will be at the bottom of the stroke. This could be either directly after firing which means both valves were closed and the exhaust valve is beginning to open to exhaust the gases as the piston starts to travel upwards. If the piston is at the bottom prior to the compression stroke, the intake would have been open to allow fuel to be drawn into the cylinder, and should be closing / closed as the piston travels upward to compress the gases.

(quoted from post at 08:51:45 03/05/21) Jeremy ,I don't know if you know it or not,but there are 2 sets of timing marks on that flywheel 180% across from each other.
Remove #1 plug and with your finger in the hole ,bump the starter till you just start to feel compression then stop.Roll engine over by hand till you see the timing marks . Lone op 4% then pull the cap and line rotor up with a cap tower,that is your #1 plug location then wire the rest 1243 in the direction the rotor turns.Replace plug and try starting.

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To everyone. Thank you so much. This did the trick. I wasn't seeing the second set of timing marks because they were obscured with superficial rust. Once I felt the compression start with cylinder #1, I used Q-tips and rubbing alcohol to remove as much of the superficial rust as possible. After advancing a few times and cleaning I saw "15" show up. I was able to get the flywheel to the 4 degree mark. I adjusted the rotor to point towards the #1 cylinder and then worked the points. It fired up immediately and we all rejoiced! We still have a few more adjustments to make to get it to run a little smoother but I was able to drive it around the yard for the first time.

To other questions, yes, I had to replace the rotor twice because it broke two times. The distributor cap wasn't seating correctly and the rotor was hitting the sides. A guy who was helping me out looked at the cap and said it didn't quite look right for an 8N. We purchased a new cap and saw some slight differences in the shape. The advice to not spray starting fluid directly into the cylinders again is noted. I have a healthy respect for starting fluid.

Again, thank you so much to everyone for taking time to share your wisdom and advice. J

jimtrs,

I think you know this and just wrote it incorrectly. At 180 degrees out the # 1 piston will be at the top (end of the exhaust stroke, about to go down on the intake stroke)not the bottom, and the valves will be on the rock. On a 4 stroke engine a piston is at the top twice, correct for firing only one of those times. The rotor position is 180 degrees apart for those two times, 90 degrees from the timing marks when the pistons are at the bottom of a stroke. Seeing or feeling a piston at the top, without knowing if it is completing the compression or exhaust stroke, is often how folks end up 180 degrees out on timing. Piston position, by itself, gives only a 50/50 shot of being right for timing.

Get your ESSENTIAL MANUALS and stop guessing and trying everything under the sun -One Step At A Time. Most likely mucked up electrical system. Start by disconnecting the battery and take to a shop to get tested. While out/no power connected, go thru entire wiring. Decide what you want - OEM 6V/POS GRN or a 12V job. You'll need the document "WIRING PICTOGRAMS by JMOR" for all the correct ways to wire these N's. What does "...corrected the wiring..." mean? If system still has the generator, and a 12V battery it will still work and not the problem. Is the VR in the system? OEM Electrical is 6-VOLTS, POSITIVE GROUND. Define what "...the cap was not the correct design..." . You need the distributor set up correctly before you can time engine correctly. Since you already have a 6V battery and generator, and if the VR is still in the system, I suggest you go to the OEM 6V/POS GRN setup. Verify the entire wiring system is correct BEFORE applying power. Leave lights disconnected for time being. Can reconnect after wiring is corrected. Firing order is 1,2,4,3 CCW. If you decide to go with 12V you'll need an alternator (why else would you want 12V ???). Whatever, be sure you have a fan belt tensioner device -without one you will never charge the battery. 6V requires heavy, thick as your thumb battery cables, 12V uses smaller dia ones like on your F-250. Forget carb/fuel til electrical is corrected -we'll get to that later - "...the carburetor is relatively new..." and "...we did a quick look..." means nothing. How do you do a quick look? "New' anything means Made In Cheena and certainly nothing is preset at the factory as there is no QC there. A simple fuel flow test will verify if carb isn't plugged.

FORD 8N TRACTOR ESSENTIAL OWNER/OPERATOR/PARTS/SERVICE MANUALS:



Tim Daley(MI)

(quoted from post at 08:32:52 03/06/21)
jimtrs,

I think you know this and just wrote it incorrectly. At 180 degrees out the # 1 piston will be at the top (end of the exhaust stroke......

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Ooops!
Of Course.
I was thinking the op had the flywheel (read crankshaft) rotated 1/2 revolution.

From one Jim to another - Thanks!

(quoted from post at 06:52:51 03/06/21) Get your ESSENTIAL MANUALS and stop guessing and trying everything under the sun -One Step At A Time. Most likely mucked up electrical system. Start by disconnecting the battery and take to a shop to get tested. While out/no power connected, go thru entire wiring. Decide what you want - OEM 6V/POS GRN or a 12V job. You'll need the document "WIRING PICTOGRAMS by JMOR" for all the correct ways to wire these N's. What does "...corrected the wiring..." mean? If system still has the generator, and a 12V battery it will still work and not the problem. Is the VR in the system? OEM Electrical is 6-VOLTS, POSITIVE GROUND. Define what "...the cap was not the correct design..." . You need the distributor set up correctly before you can time engine correctly. Since you already have a 6V battery and generator, and if the VR is still in the system, I suggest you go to the OEM 6V/POS GRN setup. Verify the entire wiring system is correct BEFORE applying power. Leave lights disconnected for time being. Can reconnect after wiring is corrected. Firing order is 1,2,4,3 CCW. If you decide to go with 12V you'll need an alternator (why else would you want 12V ???). Whatever, be sure you have a fan belt tensioner device -without one you will never charge the battery. 6V requires heavy, thick as your thumb battery cables, 12V uses smaller dia ones like on your F-250. Forget carb/fuel til electrical is corrected -we'll get to that later - "...the carburetor is relatively new..." and "...we did a quick look..." means nothing. How do you do a quick look? "New' anything means Made In Cheena and certainly nothing is preset at the factory as there is no QC there. A simple fuel flow test will verify if carb isn't plugged.


Tim Daley(MI)

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First, thank you for the recommendation for the manuals. Purchasing the owners manual was the first thing I did after purchasing the tractor. I read through it which was helpful in some ways. Reading various posts in this forum has also been helpful. Thank you also for the suggestion about wiring diagrams. I actually found the wiring diagram for a 6V side mount system at the same time as I got the owner's manual. When I said, "corrected the wiring" I meant redoing the 12V conversion wiring to the 6V wiring per the wiring diagram.

As I stated in a previous reply in this discussion, the statement that there were two sets of timing marks 180 degrees apart solved the problem. I had to remove some surface rust on the flywheel to find the correct set of marks. The tractor is up and running.

As always, thank you for your advice and patience.

Jeremy

JeremyMorris ,Your welcome glad to help you , and Thanks for the update on your success on getting it running again.May it run a long time.