1949 8N troubleshooting

8N still running rough so let me go through what I've done. just bought New to me 1949 8N Tractor was running a 5' brush hog fine then one day the JB weld that was on the exhaust manifold gives out and with it went all the umphf other than to limp it back to barn. I replaced Manifold with new replacement that came without a gasket, so I salvaged the original, no breaks but it is tired and probably not sealing enough, but it is quieter new gasket is on order. Checked fuel by removing bolt on bottom of carb, good flow over 1minute. 12 volt converted, replaced spark plugs with new 347's and copper core wires. Compression dry results; #4 105psi (black oily gunk on sparkie)#3 105psi (black but dry sparkie) #2 110psi (black but dry sparkie)#1 120 psi (black but dry sparkie). I changed oil and filter for good measure to find that the previous owner had the wrong filter in the can with no seal so he used silicone goop. Changed Ignition switch and had no better results. front mount distributor cap had #2 tower cracked so I replaced that, there was NO gasket on the cap so I cut one out. I inspected the rotor and cleaned off mild residue, pulled the distributor to look at points and saw the fixed point had been bent out towards housing so only the bottom of point made contact with moving point. I saw that when I rotated the shaft and saw that the arm that was riding over the lobes wasn't really separating the points so I tried to widen the gap and realised I couldn't anymore. Thats probably why the fixed point was bent back. I set the points back to what I thought was previous but Now she wont start. Thats right I killed her. I need help, I need that tractor to work, I've got weeds overgrowing my land, steers and donkeys are getting lost.

Priest......ya mucked around with the points and now it won't start. You don't suppose there is a relationship, do you???

Sounds like you either shorted-out the points flat conductor ...or... cracked opened the flat conductor. Byte the bullet and buy NEW points. $20 (cheap) Gap it 0.015" on all 4-lobes.

Remember to "polish" the points with $1 bill clamped between the points when off-cam (points are spring-loaded closed) Iff'n yer really cheap, a torn strip of heavy brown grocery sack will also work. ......Dell, yer self-appointed sparkie-meister

W/ all that work in the distributor, you've probably got a short somewhere.

First, make sure you have battery voltage to the top of the coil. If you don't, stop right there & post back w/ that info.

Assuming that the bushings & advance weights are ok, the most common electrical failure (no spark, weak spark) points on the frontmount are:

1. The insulator under the concave head screw.

2. The insulator at the end of the points where the copper strip attaches.

3. The copper strip grounded to the plate.

4. The condenser wire grounding.

5. The pigtail/tab not making contact.

6. Incorrect positioning of the spring clip on the plate causing the pigtail to ground.

7. Incorrect seating of the coil on the distributor.

8. Water/moisture inside the cap due to gasket failure or the absence of a gasket.

9. Dirty/corroded/incorrectly gapped points

10. Burned rotor, cracked/carbon tracked cap.

Unless the coil is cracked or shows a dead short, chances are it's fine; square coils rarely fail cold.

(You can change points everyday & it will not fix bad bushings. If you are having trouble w/ points failure, check the shaft. If you detect movement, chances are it needs new bushings.)

I'd say you are having problems 1,6 or 7. To find out, you need to pull the distributor & do a continuity check.

First, replace the points then dress those new points w/ a piece of card stock or brown paper bag.

Having learned the hard way, I most always use Blue Streak brand points. They are made by Standard parts & available at many auto parts stores. (frontmount points also fit 41-48 Ford 6 cylinders as I recall) Beware of sticker shock: $16-18 a set. My next choices are Wells or Echlin. Look for a brown rubbing block. Unfortunately, many folks have experienced problems w/ points made by Tisco, Sparex, A&I Products and any TSC ignition parts..


Next, you need to do a continuity check on the distributor.

Make sure your meter/light works (don't ask....)

Now, follow these steps:

1. Coil off, cap off, points open. One probe on the brass screw & the other on both sides of the open points. On the side closest to the cam, you should have continuity. Not on the other side! If you do, you will also have continuity everywhere because the points are grounded.

2. Coil off, cap off, points open. One probe on the brass screw & the other anywhere on the body of the distributor. You should have no continuity! Now, rotate the tang on the distributor....as the points open & close, you have continuity (closed) and lose it when they open.

3. Coil on, cap off, points open. One probe on the lead on the top of the coil, the other on the cam side of the open points. You should have continuity!

4. Coil on, cap off, points open. One probe on the lead on the top of the coil, the other anywhere on the body of the distributor. You should have no continuity!

At this point, I just put the distributor, coil & cap all back on the tractor as a unit (it’s easier to do this from the left side). The reason I do this is because it is real easy to get the cap or coil mis-aligned trying to put it back together one piece at a time & the result is something gets broken or you get a ‘no spark’ problem.
50 Tips

Dell actually any piece of clean paper will work. When I'm going to work on any thing with points I just put a piece of puter paper in my pocket.

Rick

"front mount distributor cap had #2 tower cracked so I replaced that,"

Look at the picture.

W/ a new king pin & bushing & correct axle spacers, the right side of the axle is slightly more than 1/2" from the #2 nipple w/ the axle as high as it will go. If you don't replace the king pin, you will be replacing the cap soon. The axle is hitting the nipple.

" there was NO gasket on the cap so I cut one out."

Take a look at failure points 5 & 7 in my previous post. If the gasket you made is too thick the coil will set to high causing the pigtail to lose contact.

The other picture is of the 3 gaskets & dust seal that come as a package from plenty of on-line parts places; I think that set was $2 or so from nnalert's.


50 Tips

Rick.......yeah, as long as its not toilet paper, eh? I recommend the dollar bill 'cuz it is weird enuff to stick in a guys mind. Points gitt INVISIBLE corrosion that hassta bee polished off or you won't gitt enny sparkies. ......Dell

Dell for the Canadian challenged , it cost $5.00 , not fair $4.00 more. Loonies & Toonies don't work.8^) Stan

success!! the replacement of points with proper gap has returned my red belly to running condition smooth and powerfull is the engine. Look out weeds here I come!! Thanks to every one and especially to Her Sparkmeister, Danke.