Farmall 350U Ignition Problem

Does not start no spark.

several moths ago popped tire. ran a little rough at that time. took several weeks to get tire fixed, after that it didn"t start.

there is no hood on it and it got rained on after tarp blew off.

replaced the ignition switch and the starter drive gear and eliminated the charging circuit as these were issues before and made it hard to troubleshoot spark issue. now starter runs strong and battery is fresh charged. the main starter terminal is not the best but i got it to work after some futzing. seems to have good contact now runs real fast. will be replacing it but it is not touching the casing now (checked with meter) and reasonably tight to the coils inside.

its wired 12v negative ground. not sure how many parts were originally 12v, was made in 1957 and it had a 12v generator on it when i got it. now it just runs on the battery.

i measured 12.5v at + coil and - coil with key on; then while starter is turning drops to 10v.

the ignition coil was replaced, the old one the terminal broke inside when i was troubleshooting (cleaning and tightening connections). new one came from tractor supply says 12v no resistor needed (and i don"t have a resistor).

added all the parts from the tractor supply farmall tuneup kit (cap, rotor, plugs, points, condenser) no help

checked the point gap several times. a little play in the distributor making it hard to set.

have not tried spark plug direct to coil yet

Make sure the points are clean/no corrosion.Had an Oliver 60 do that.

Have you tried checking a plug for spark to know for sure that is what the problem is? I'd also suggest making sure the rotor is turning inside the cap in case something is sheared or stripped in the distributor.

Take the wire off of the distributor at the distributor. With plastic handled pliers, brush it against a ground (shiny metal) with the ignition turned on. If it sparks a little when touched to ground, there is voltage where it should be. Shut off the ignition. Next open the cap and put a small piece of plastic (strip of butter tub lid or the like) between the points. Now, while the cap is off, and the ignition on, touch that loose wire to the distributor terminal where it belongs. If it sparks a little there, the points are grounded to the distributor housing and it could be the condenser wire, or the through stud, or insulator that are causing the problem. There should be no spark. Next remove the plastic, and make sure the points are together. Now touch the wire to the terminal if no spark, the points are not conducting, and need to be cleaned and polished. A good polish is a paper match striker stripe. Then wipe them with a folded dollar bill. (no lint)
The point gap is .020" when the cam is pushing the points open as far as possible (High point of the 4 lobes)
If there is wobble in the distributor cam, it will never run correctly. The movement must be less than .001" at the cam. Jim

tractor is far from shop and farther yet from my house so i need to prepare what all i can try. it's no fun fixing this much electrical stuff out in the woods (have to cross a creek) but too hard to try to drag it back across the creek.

i tried checking spark with timing light and with a spark plug connected to distributor then grounded to engine block. i could see the spark jump across a year ago can not see it now.

i read on another post to try hooking a plug to the coil directly. have not tried that yet will do later today. kind of expecting it NOT to work.

with the cap off i watched the points open and close while cranking

i saw on another post someone thought their starter was taking all the juice away from the ignition system i guess that is possible. i did see the voltage at the coil + go down to 10v during cranking. anyone know a way to tell for sure? does a 12v coil need all 12v to work?

i tried cleaning the points and changing them to new ones.

i can't try the old coil again because it has a broken terminal.

i got the coil from tractor supply. it is 12v coil but the old coil was 12v as well. they only have two coils there for all tractors one 12v and one 6v. my battery is 12v and strong (tried two other batteries as well)

the ignition key is wired to +coil then the -coil goes to the distributor (the battery - goes to chassis, + battery goes to starter relay)

was writing my last post while you were posting this. this is the kind of thing i will need to be doing step by step checking. hoping to get it to run good enough to limp it back to shop. will check all this and post the results.

It runs now.

In case others have similar issue. I did Jim's procedure to check the distributor low voltage (points, condenser, etc) and that was very helpful to see the little spark and know the power was moving trough the points as it should. we should all remember this, can save a lot of time and frustration. took 5 minutes or less. thanks so much.

then i tried hooking an extra spark plug on a plug wire directly to the coil high voltage (i.e. took out the center wire from cap). grounded the plug threads to a place on the block i know was good ground (can find a spot with a meter or a test light). i just held it on that spot but you could use some kind of wire. funny thing it took a lot of cranking but all of a sudden it started sparking a little, then a little more then a little more. the first spark it made was giant then they became normal.

then i put everything back being extra careful to make good contact on the wires; and checked each plug wire with the timing light just to see it flash about every half second or so evenly.

it still didn't even pop (and i know there was fuel), so i took all the plugs out and performed dead timing check. took me a bit to feel like the pressure in #1 cylinder was being felt when the timing marks lined up (was worried maybe valve timing had gotten messed up) but it turned out to be perfectly aligned. cylinder was TDC when the timing marks aligned and the rotor lined up with #1 on cap.

by this time the battery was dead. put my spare on (have been going back and forth between batteries helps to have a spare when having this kind of issue).

started up first try.

has fired up several times since first try.

so can't say for sure what the problem was. maybe if i had cleaned the points even though they are new not sure. seemed like it just needed to break in or something. just confidence in seeing each test yield some results led me to keep trying and the problem went away. funny thing checked timing after running and was perfect already.