8N ran fine, now won't start

Kevinw8N

Member
Just bought an 8N over the weekend. Put new battery, plugs, wires and cap on. Ran fine yesterday afternoon for over an hour, then died. Doesn't want to start now. Yes, the wires on the battery are correct (now..). It has 6v system with pos ground. I did originally have the wires backwards. Thanks in advance for any help! -Kevin
 
Do you have spark at the points
is your fuel shut off valve open the whole way
maybe your fuel level is below primary on valve.
 
It is important for you to tell us if the distributor is on the front or side of the engine. The troubleshooting is different based upon the configuration of your engine.

It takes three things for an engine to run: spark at the right time, compression, & fuel/air in the right mixture. For the moment, forget about compression & concentrate on narrowing the problem down to spark or fuel.

There are three very important tools you always need to have in your N tool box: a 3 inch piece of wire w/ alligator clips on each end, a spark checker w/ an adjustable gap (* see below) and a 7/16 box end wrench. (see tip # 50 at the link below) And, you really do need a working ammeter on the tractor; it is a very important diagnostic tool. With these tools, you can quickly narrow down most N problems to spark or fuel.

Check for spark then fuel. First, turn the key on, crank the engine & look at the ammeter. What is the needle doing? Does it show a constant discharge, no movement at all, or does it move back & forth slightly? Next, hook up your spark checker, turn the key on & crank the engine. If the spark jumps the 1/4? gap, you probably don?t have a spark problem. If it won?t jump the ?? gap, you have a spark problem. If the ammeter needle shows a constant discharge, or doesn?t move at all, that also tells you that you have a spark problem. Jump the ignition switch w/ your jumper wire & see what happens. If it runs, you found the problem. If it doesn?t have spark after you jump the ignition switch, post back for more info on further troubleshooting. (and do not forget to turn the ignition switch off; see tip # 38

Next, check for fuel. Get a can & put it under the carb. Remove the bolt in the bottom of the carb; as long as the fuel is turned on, you should see gas flowing out of the carb. It should fill a pint jar in less than 2 minutes. If it?s a dribble, or runs for 5 seconds & stops, or none at all, you have solved half the problem: it?s fuel related. If gas flows well out of the carb & only stops when you turn it off at the sediment bowl, chances are very good it?s not a fuel problem.If it does not have gas coming out of the carb at a steady stream w/ the bolt out for at least 30 seconds, you have a fuel problem. First, remove the gas cap. Your vent could be clogged & it vacuum locked. If that doesn?t work, tap the carb bowl w/ a hammer handle in case the float is sticking closed. (don?t whack it w/ the head of the hammer; you can crack the bowl). If you still don?t see gas flowing, the N has three fuel screens; one in the brass elbow, one in the top of the sediment bowl & one on the stem of the sediment bowl in the gas tank. (see tip # 45) Check the screen in the elbow (see tip # 56) & the screen in the top of the sediment bowl. (don?t worry about the one in the tank) Both probably need to be cleaned. If you have the fuel knob turned on all the way, & 1 gallon or less in the tank, it may be trying to feed off of the reserve inlet which is probably clogged. Only open it 2 full turns. Put at least 2 gallons in the tank. (and do not forget to turn the gas off; see tip # 9)

There are ways to check for spark & fuel that work & ways that don't. For example, having gas to the carb is nice, but having it past the float is what counts! That?s why removing the 7/16? bolt in the bottom of the carb is the way to check for fuel. And, same thing w/ spark at the plugs. Some folks think that checking for spark means pulling a plug wire off & looking for one. Well, it's the distance the spark jumps at the plug that gives you the info you want. It takes about 17kv to jump a 3/16" gap & 22kv to jump ?? in the open air. Remember, it?s 14psi outside of the engine & about 90psi at a 6:1 compression ratio in the cylinders & compressed air creates electrical resistance, so you really need the 17-22kv to fire the plugs when the engine is running. A store bought plug checker (in the picture) will work better than an old plug because it won?t shock the snot out of you like an old plug might!

Post back with results or more questions.



*If you don?t own a spark checker w/ an adjustable gap, buy one. In the meantime, an old spark plug w/ the gap opened to at least ?? will work. Ground it to a rust & paint free spot on the engine turn the key on & look for a spark.
75 Tips
 
You said the battery wire were on it wrong and you changed it back to positive ground. Did you repolarize the generator?
 
Not sure. Everything has been painted over on the generator, so not sure if I did it right. I ran a long wire from the lug on the back of the generator to the negative post (or positive in this case). It sparked a little.

I checked the fuel, and it has a decent stream coming out of the plug on the bottom of the carb. It did start right up this morning. But it did yesterday too. It started acting up after I ran it for an hour or so.

And it has a front distributor cap. Forgot to mention that earlier. I didn't change the points etc., just the cap, plugs and wires for now. Not the easiest thing to get to on this thing!

I'll pick up a spark tester today.
 
" so not sure if I did it right."

That's one of the reasons why it's easier to polarize the generator at the v/r. See tip # 23.

" I didn't change the points etc.,"

Well, that's the key to making it perform correctly.

" Not the easiest thing to get to on this thing!"

The front distributor was designed to come off of the tractor to replace/adjust the points. To do this, remove the wire on the coil, remove the coil bail, remove the distributor cap & take the two bolts off. The base of the distributor has an offset tang & can only go back one way unless you really force it on.

The first thing you need to check is bushing wear. If the shaft has any sideways movement AT ALL, the bushings must be replaced. (see below)

Next, look at how the points & condenser are set in the distributor before you start pulling it down! Turn the tang & observe how the points open & close. If this is your first time doing it, draw a sketch! Make sure you are using quality points. I use only Wells, Blue Streak or Echlin brand points (* see below). Be careful not to ground the tip of the condenser wire to the body of the distributor when you replace the points. Do not break the little copper strip that go to the points. (If you do, make another out of the old set of points). Also, make sure the condenser wire does not go through the same opening in the distributor as the coil pig tail. The condenser wire goes through the opening on the top right.

Look at the old points; are they burned, pitted or misaligned? Check the point gap, .015 on all four lobes. Make sure the blade is at a perfect right angle to the points. You want to feel just the slightest bit of drag when you pull the blade through the points. Set the points on the high side of the cam and ensure they align correctly. Make sure you have the star washers under the screws on the points. If you need to replace the 8-32 X .19 fillister head screws, ensure that the new screws do not interfere with the advance weights. Dress the points by running a piece of card stock or a brown paper bag through them. New points sometimes have an anti-corrosive dielectric coating on them & old points can corrode or pick up grease from a dirty feeler gauge or excessive cam lubricant. And, don?t forget to lube the rubbing block w/ cam lube; not Vaseline, not bearing grease, but cam lube (** see below).

If you are using quality points and cannot get the gap to open to .015, chances are you need to replace the bushings.

Now, set the timing. Get a meter or test light, a 21/64? drill bit (*** see below) & a metal straight edge. Put the distributor face down w/ the condenser on the left & the timing plate lock screw on the bottom. Look at the end of the shaft: it has a narrow side & a wide side. Make sure you can tell the difference. Now, place the drill bit in the bottom mounting hole (this will be your reference point for measuring). Next, place a straight edge on the wide side of the tang on the shaft as shown in fig. FO83 in the picture. Rotate the shaft CCW (as viewed from rotor side OR CW as viewed from back/tang side) until the straight edge is ?" beyond the outside edge of the drill bit you stuck in the distributor mounting hole. At this distance, the distributor points should start to open (get your meter/light out now & check). If not, loosen the timing plate lock screw and turn to advance or retard the timing (move the plate down to advance timing, up to retard). Remember, each one of those little hash marks represents about 4? of timing. Keep adjusting until you get the proper ?" setting. (if the plate won?t move, you might need to remove the big C clip to loosen it a bit) As you?re adjusting, eliminate backlash by turning the shaft backwards (CW as viewed from the front) and bring the shaft forward (CCW as viewed from the front) to measure your setting. This ?" setting will get you static timing at top dead center.

As you can see from the picture, this particular distributor needed to have the timing advanced by about 8? (two hash marks) to achieve the ?? measurement.

After you set the points & timing, do a continuity check before you put the distributor back on the tractor.

Before you start, make sure your meter/light works.

With the distributor still off the tractor, 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. Put the coil on the distributor, 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. The reason I do this is because it is real easy to get the cap or coil misaligned trying to put it back together, one piece at a time. The result is something gets broken or you get a ?no spark? problem.

It's possible to put it back on wrong & break it. Look at the slot on the end of the cam shaft. Whatever angle it happens to be, turn the distributor tang to match it. Make sure you can tell the wide side from the narrow side on both the cam & distributor! (close counts). Place the distributor on the front of the engine, gently push it in place & slowly turn the distributor body until you feel the tang slip into the slot. Rotate the distributor body until the bolt holes line up. Hand tighten the two bolts until the distributor body is flush with the timing gear cover.

Double-check your firing order & plug wires. It?s 1-2-4-3, counterclockwise. It?s very easy to cross 3 & 4.

And finally, do not forget to remove the distributor on an annual basis (more often, depending on use) to check the point gap and re-lube the cam.

* NAPA part numbers:

? Points: FD-6769X
? Condenser: FD-71
? Rotor: FD-104
? Cap: FD-126


** Distributor cam lube:

http://www.napaonline.com/Catalog/Result.aspx?Ntt=ECH+ML1&Ntk=Keyword&Nty=1&Dn=0&D=ECH+ML1&Dk=1&Dp=3&N=0
** Distributor cam lube

http://www.carquest.com/webapp/wcs/stores/servlet/subcategory__10151_-1_10651_11340


*** Rather than the drill bit, a jig made by Dan Allen (The Old Hokie) will make this task quicker & more accurate.

http://windyridgefarm.us/


**** Unscrew the plate hold down screw & remove the C clip to get the plate out. Remove the shaft & weights. The weights should freely move.


There are three ways to replace the bushings in a front distributor:

1. Buy new bushings (part numbers 9N12120 front & 18-12132 rear). Press out the old ones, press in the new ones and ream to fit. CAUTION: do not try this unless you have a press & know how to use it. If you break the base, a new one costs $130. If you bend the tower which holds the front bushing, a new plate will cost you $30.

2. Take the new bushings and distributor to your local machine shop.

3. Send the distributor out for bushing replacement if you do not have a local machine shop.

Make sure your distributor isn?t worn out; check the wear parts with a micrometer and compare what you have to the factory specs (below).

Factory Specs:

Shaft top .4367 / .4370
Shaft Bottom .8625 / .8630
Cam Flats .789 / .791
Cam Lobes .869 / .871
Base Tang .177 / .178
IMG_20140212_144953_385_zpsd84210ac.jpg

75 Tips
 
Sorry for the late response, got side tracked. But did check for spark, and it seems ok. When it's cold, it starts right up, the problem is after it's ran for a while and I shut it off. It doesn't like to start again.

So I'm wondering if anyone has changed the ignition system to the electronic version? Does that eliminate the distributor cap etc. that is on there now? also thinking about changing over to a 12v system with an alternator. Thoughts on that? I'm no mechanic, but am mechanically inclined.

Thanks!
 

"So I'm wondering if anyone has changed the ignition system to the electronic version? Does that eliminate the distributor cap etc. that is on there now? also thinking about changing over to a 12v system with an alternator. Thoughts on that? I'm no mechanic, but am mechanically inclined."

yes, many here have installed EI. as far as i know, it only replaces the points.

both my 2N (i converted it) and my allis WD (PO converted it) are 12 volt. 12 volt conversion is simple - but don't do it expecting it to cure this problem.

u say u had spark - will that spark jump a quarter inch gap?

if so, the next thing to check is fuel flow. these things should be checked as soon as the problem manifests itself. spark first, if that's good, pull the drain plug on the bottom of the carb with the fuel turned on. it should fill a pint jar with gas in 2 minutes or so.
 
(quoted from post at 15:44:10 10/05/16) Sorry for the late response, got side tracked. But did check for spark, and it seems ok. When it's cold, it starts right up, the problem is after it's ran for a while and I shut it off. It doesn't like to start again.

So I'm wondering if anyone has changed the ignition system to the electronic version? Does that eliminate the distributor cap etc. that is on there now? also thinking about changing over to a 12v system with an alternator. Thoughts on that? I'm no mechanic, but am mechanically inclined.

Thanks!

If you can't make it run on points, what makes you think you can make it run on EI? Right now, you have a 6 volt tractor that won't run on points. $250 later in parts for EI and a 12 volt conversion and you will likely have a 12 volt tractor that won't run on EI. Fix it before you do any conversions.

Have you checked everything I suggested? Did you check for spark and fuel as soon as it stopped?
 
Didn't say I thought it would solve the problem, just asked the question if anyone here had done it. And it does run now, just doesn't want to after it's ran for a while. It runs great up to that point.

I didn't get a chance to check everything right after it happened the last time, just checked it once I got it into the garage. Next time I run it and it happens, I'll check both those things right away. The last time I checked the fuel flow, again, it was in the garage. I'll see if I can snag one of the wife's mason jars and see how long it takes to fill it.
 
(quoted from post at 16:23:24 10/05/16) Didn't say I thought it would solve the problem, just asked the question if anyone here had done it. And it does run now, just doesn't want to after it's ran for a while. It runs great up to that point.

I didn't get a chance to check everything right after it happened the last time, just checked it once I got it into the garage. Next time I run it and it happens, I'll check both those things right away. The last time I checked the fuel flow, again, it was in the garage. I'll see if I can snag one of the wife's mason jars and see how long it takes to fill it.

Have you replaced the points and set the timing yet? You don't need to wait for it to cut off to do that.
 

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