Ford 8N having trouble starting -- many troubleshooting steps take -- suggestions?

[sd455dan]

looking at those plugs ,if you have a new set it wouldn't hurt to replace them-cold weather,fair amount of carbon on insulator and electrode, but that doesn't explain quitting after its been running for a while, one other thought and its been a while since I worked on my sisters 8N, vacuum leak between carb and intake or intake and head . No whistling sounds like an air leak when it was running? Bolts tight.

 

[Soundguy]

yep.. those look in need of a good soak in carb cleaner can.. and then an abrasive cleaning.. then a blow off / regap.

 

[PorkChopsMmm]

I installed new H12's.

The battery wasn't the problem -- for some reason the solenoid was stuck. I bypassed it and got the tractor attempting to fire up and it still did not work. Next time I tried the starter button it cranked but did not fire up -- same problem as before even with using starter fluid.

I did find a difference this time around -- the spark plugs were not sparking. Both with new plugs and old. I pulled the wires off each plug and put them on one of the older spark plugs -- no spark.

Sooo.... back to the drawing board. I had spark last week. I got the coil off of the top of the distributor and the only thing I could notice is the spring on the bottom had a little singe mark. When I popped the coil back on top I could see that it sparked a little when it became seated (I left the key in the 'ON' position).

So should I replace the coil, points, etc? I made sure the wires were seated in both the distributor and on the plugs and put dielectric grease on at both ends. Yes the plug wires are old but they were sparking last week.

 

[Ted Summey]

A set of plug wires is cheap and will rule out that problem. Seems like you have worked on either end of the plug wires but still have the issue. Since it is intermittent it sounds electrical in the ignition system. Shorted ignition wires is a prime place for such a problem (including the coil to distributor wire) Messing in the distributor on a tractor that was running should only happen after you rule out the simpler issues like wires.

Make sure air filter and exhaust is clear - no mouse nest etc. so the engine is aspirating properly.

 

[eddie48]

I vote for bad, burned points, probably due to the change to 12 volts. Weak spark can give all of the symptoms you have talked about. Often disguised as not getting fuel. Clean and re-gap the points ( I think .020" gap) and try again. If it works for a while, then be sure that you have the resistor in line with the power to the coil to reduce the incoming voltage to 6 volts, like it was designed for.

 

[PorkChopsMmm]

Thanks for the help guys. I did not convert this to 12V -- the previous owner did some time ago. I had it working all summer, fall, and for most of this winter so I think it is something beyond the 12V conversion. Isn't the black top coil a 12V coil? I have seen those in in kits... the 6V is grey and the 12V is black... at least so I thought.

Wouldn't only some of the spark plug wires be bad -- not all 4? I took the front off of the distributor but it was hard to see -- although what I could see did not appear burned or anything. I guess my next step is to source points and if that doesn't work a new 12V coil. From what I have read I should order the points online and not go with something from NAPA etc?

Thanks guys. I just called up my snow plow guy -- another $100 for him to plow. Wish I would have ordered $100 of parts a week ago!

 

[eddie48]

Sorry. Got carried away. The 6 volt requirement is for the points, not, necessarily the coil. A 6 volt coil should work ok with 12 volts, just puts out a hotter spark. The real problem is the points that will burn on their contact area with too much voltage. The burned area, then, will not conduct electricity and you will get no or intermittant spark as a result. You can clean the points with a file or sand paper without removing them from the distributor. Then reset the point gap, put the cover back on and try to start and run. Running under a heavy load will require a better spark than running with no load. Seems that the spark has a harder time jumping the spark plug gap when the engine is working hard.

 

[Ted Summey]

Over time the resistance in the wires goes up reducing the voltage and that makes he spark. It appears that your tractor has spent some time outside in the weather. Moisture can penetrate old plug wires that are weathered, cracked or brittle. Additionally, you have pulled the wires repeatedly in checking plugs and well could have separated the contacts on the ends from the conductors in the wires. So I do suspect that you have wires that need replacing. They are inexpensive, simple to replace and will make sure the spark gets to the plugs consistently.

You have indicated that you had spark at the plugs last week. It isn't likely that points have burned with what you have done so far.

My Farmall presented me with similar symptoms, I did everything BUT replace the wires. I had a replacement set on hand - changed them out and it has run perfectly since.

If it were me, I would purchase the points, distributor cap, rotor, and condenser in addition to the wires. I would replace the wires first and see if it runs. If so, decide if you want to complete the tune up. If it doesn't run, proceed with the rest.

 

[PorkChopsMmm]

Thanks guys. I will pull the distributor tonight, now that I know where the other bolt is, and check the points. It is about the only thing I can do with parts on hand. I will order new wires, coil, etc. once I have seen the points. I agree it is good to replace the wires -- just wish I had a local source.

Thanks for all of the help and I will post back tonight with pictures of the distributor/points. I need to get this puppy working because I got a nice 3 point dirt scoop on Monday and plan on picking up a 3 point carry all in the next week or two. She needs to be ready for Spring!

BTW yes, this tractor is always outside. Wish I had a garage or lean-to to park under but we just built a house on 20 acres and haven't had the funds for a garage. Maybe in another year or so.

 

[Ted Summey]

Hey even a "pop up" canopy would help. My first place to park a tractor was under my deck - it is 10 feet off the ground so I put tin roofing under it. Your auto parts store may have a generic set of wires that will work. Less than $25 here.