Please Help - Ford 8n Will not run for more that 15 Seco

[[email protected]]

Ok here it goes. I am trying to get a ford 8N side mount tractor running for the last month or so. The tractor was my wife's grandfathers that was in my father in laws possession and sat for 10 years. I wanted to get this tractor running so I followed similar forums and got it to run like a top. I had it for a year and it built a driveway, cleared snow, moved a ton of dirt, etc. Well once the father in law knew it ran so well, he came and got it back from me

Moving forward, he had it again for 10 years and didn't move, wasn't even sitting in a level place the entire time. One day I come home from work and it is once again sitting in my driveway. Called him and it doesn't run and he doesn't want it anymore. It had 4 flat tires, rusty, generally in bad looking shape.

First of all, got tires all back in shape so I could at least roll it around. Then started from scratch. I changed oil, oil filter, cleaned air filter, put oil in spark plug holes and let it sit for a few days. Then hooked a battery to it and nothing. Had to take starter apart and clean and put back together. Violia, turned over but no spark. 12V Coil had a small crack in it but was still functional. Changed it out anyways with an internal resisted 12V coil. Changed battery, points, condenser, spark plugs and wires. Now I have excellent spark at plugs, nice and blue, jumps 3/16 easily but no fuel. Took apart tank valve assembly, cleaned it and both screens really well. Now bam, starts right up but wont stay running and when it does, it back fires like crazy and had limited power. I then fully rebuilt carb and made sure ports were cleaned out really well. Try again, no change until I completely burnt out solenoid. I then replaced solenoid but had no spark again so I changed out several wires and solders new ends on several others. Spark again, lots of fuel when I pull carb drain plug. but will only fire for 15 seconds and quits, choke helps a bit but still dies off anyways. I have spark and fuel immediately after it runs. Plugs however seem dry when I pulled them so....... compression test.

Cyd#1 - 90 dry, 100 wet
Cyd#2 - 70 dry, 85 wet
Cyd#3 - 90 dry, 105 wet
Cyd#4 - 85 dry, 100 wet

I then brought #1 cylinder to TDC and could see the timing mark so I checked the distributer and its pointing at cylinder #1. I once again opened carb and cleaned every passage...... No go.

I am at a loss, I've put so much time and money into this thing already and cant even move it around yet. Can someone please pitch me a few ideas.

 

[jimtrs]

Poss resticted fuel flow. Just enough to start, but not enough to keep running. Leans out and dies. sits for a bit, and slowly fills carb bowl for another few moments of running. Check fuel flow at bottom of carb immediately after stalling out

 

[[email protected]]

I tried again. It ran for 30 seconds this
time and once it stalled it had great flow
at carb drain.
Forgot to mention, starter switch is after
market (4 post). Shpuld I replace? Also
have not replaced distributer head, should
I?
I also noticed that valve covers are not
sealed well, should that matter?

 

[WNM]

(quoted from post at 14:17:51 11/27/21) I tried again. It ran for 30 seconds this
time and once it stalled it had great flow
at carb drain.
Forgot to mention, starter switch is after
market (4 post). Shpuld I replace? Also
have not replaced distributer head, should
I?
I also noticed that valve covers are not
sealed well, should that matter?

Is there a mesh filter that is behind the fuel inlet elbow to the carb that is clogged?

 

[[email protected]]

Screen is good. Seems like lots of fuel as
it floods after trying to start it a few
times. Plugs are not wet though and it
seems like the carb will shoot air out the
intake from time to time.
This thing has me stumped.

 

[Jock(OR)]

You said you replaced the coil with one that has an internal resistor. Did you bypass the
ballast resistor behind the instrument panel? That could add too much resistance once it warms
up.

 

[[email protected]]

Yes. I bypassed resistor. I have full voltage between points

 

[Den N Ms]

(quoted from post at 22:07:35 11/27/21) You said you replaced the coil with one that has an internal resistor. Did you bypass the
ballast resistor behind the instrument panel? That could add too much resistance once it warms
up.

[email protected] off the side mount distributor does not use a ballast resister. Next check spark at each plug wire that should jump at least 1/4" or more with a spark tester or at least a phillps screw driver held in the plug wire and at least 1/4" to head bolt.
If 12 volt system , to test run a jumper wire from battery positive cable to wire opposite side of the distributor wire to the coil and jump it to test. Try some starting fluid in the carburetor intake to get it started up.
And Yes the solenoid should be changed to the proper 3 terminal so the neutral lock out will work,safety first.

 

[WNM]

(quoted from post at 15:11:42 11/27/21)

(quoted from post at 14:17:51 11/27/21) I tried again. It ran for 30 seconds this
time and once it stalled it had great flow
at carb drain.
Forgot to mention, starter switch is after
market (4 post). Shpuld I replace? Also
have not replaced distributer head, should
I?
I also noticed that valve covers are not
sealed well, should that matter?

Manifold and gaskets good on the intake part of the manifold good?

 

[Btzj02]

It runs for 15 seconds and quits. You also said you immediately check and had fuel in float. I currently have 3 brand new condensers in my new parts box due to the fact that I have had bad luck with even brand new condensers! That short of a running time may point to a bad condenser!

 

[Trz]

How do you check the condenser?

 

[Btzj02]

Never had much luck testing a condenser even with my old work Fluke multimeter. The new condensers seem to bench test good but then fail when installed. I hate to
say it but I just use an old condenser, (from a running engine), from a previous tune up. I switch out the suspected condenser and try the old, good, condenser.
Not a high tech method but it is an easy check!

 

[Jim L WA]

While I was reading your post, my first thought was, did his Father in law bring back the same tractor?
But I have to agree with WNM, the fact that the choke helps some, but it still dies, the plugs are dry when you look at them, I would check for a cracked manifold or bad gaskets. You could try spraying some starting fluid around the manifold if you can get it running long enough.
As for the condenser, it doesn't have time to heat up and break down, so if your getting spark, I don't think that's it. But they don't cost much, so you could change it just for grins.

 

[deanostoybox]

Had one that was like that once. Turned out the main fuel passage between the main adjusting needle and the main jet was plugged up with mud. It had been cleaned and wire poked through all passages, and spray can carb cleaner would go through full stream, but the mud in the passage made it act more like a capillary tube than a calibrated orifice. After removing the main jet and properly cleaning that passage it worked great.

 

[[email protected]]

I could use a bit more help hit this comment deanostoybox. I have a small plug in the bowl that seems to line up with the main jet. If I remember correctly, I can see straight through, where would the mud your referring to be hiding? And how could I solve?

 

[deanostoybox]

IF that is your problem and you have the little plug as you say, then all you need to do is remove that plug, back the main adjusting needle out so the tip is out of the way, and scrape the sides of the passage up to the jet with a wire. Removing the bowl drain will also be a good idea as it drains through the same passage and anything you scrape loose will fall down there. Then blow it out real well with carb cleaner or compressed air.

 

[[email protected]]

Update!!. While making adjustments and
checking spark and such, I noticed that
the spark at each plug jumped a 3/16 gap
about 3 times then no longer does. (Seen
some very small arcs where i grounded the
3/16 spark plug but no spark where it
counts)It will however jump normal plug
gap every revolution. Then tried a 3/16
gapped plug on the (coil to dist) wire and
seemed to spark everytime.
I think this would explain the 15 second
run time??? Now I'm thinking dist cap,
ignition switch, condenser, loose ground??
Thoughts??

 

[[email protected]]

Update!!
While I was making adjustment and checking spark again and such, I noticed that I will get spark at each cylinder that jumps a 3/16 gapped plug for a few cranks and then
misses occasionally or stops all together. At his point, I can see it trying to arc where I ground it out on the block but has no spark where it matters. I do have spark
if I test using a 0.025 gapped plug.
Then I used the 3/16 gapped plug on the (coil to Dist) wire and had great spark there. I'm thinking that the few good sparks at the cylinder on my first few cranks are
what is making it start and then when the spark weakens, the tractor is stalling. My mind is now going to Dist head, condenser, Ignition switch, ground connection???
Thoughts?

 

[Jim L WA]

This is from your original post: Changed battery, points, condenser, spark plugs and wires.
So it looks like you never replaced the distributor cap or rotor. So, yes I would do that and see if it helps.
One of the other posters pointed out that the spark needs to jump 1/4 inch in open air not 3/16.
When you remove the distributor cap and rotor check the shaft for any lateral movement.

 

[[email protected]]

Problem solved!!
Replaced main ground cable while waiting
for parts to show up and it fired right
up. Woohoo! Now have a set of new problems
(seized left brake, badly leaking valve
covers). But I'm headed in the right
direction.
Thanks everyone for the suggestions