CODI

Member
I was mowing the back yard today, which had extemely thick grass and the 8N was struggling go up the hills mowing. It would just bog down something awful. Then when I parked it to cool off before I cleaned it off, It would not start back up. It would hit every now and then but would not start. Is this a vapor lock? Or are the plugs shot?
 
Codi,

I would do what john from NY will have to do. Diagnose the problem. Do you have fuel in the tank and at the bottom of the carburetor out the plug? Is there a vapor lock on the tank due to a an old gas cap and a plugged up vent hole?

I would follow what Bruce has to say about the spark diagnostics in the same thread. If a plug fouled out I doubt it wouldn't start--all thing being equal. It would run poorly and sound like garbage, but it should start.

Start basic and proceed from there. It is also true that when in heavy grass you will have raise your mower deck or go to a half swath cut.
 
I can tell you what is not causing the problem: vapor lock.

It doesn't have a fuel pump, so it can't vapor lock.

It can vacuum lock, but not vapor lock.

But don't guess. Just run the usual diagnostics (tip # 13) like G6 just suggested.

Post back w/ results or more questions.
75 Tips
 
We just went through the ignition diagnostics a few weeks ago and everything was fine. I will check the ignition stuff again but everything was great. Sometimes this ole thing just aggravates me.
 
" We just went through the ignition diagnostics a few weeks ago and everything was fine."

You could have done it this morning & still have a problem this afternoon. And you need to run the diagnostics AS SOON as it stoops running. Not even 5 minutes later. Many times, these problems are heat/time related.

" Sometimes this ole thing just aggravates me."

Check out tip # 42. Done that yet?
75 Tips
 
Tip 42 was done less than a year ago. The tractor never quit. I shut it off and it won't start back up.
 
Codi,

Don't be surprised if the diagnostic you several weeks ago is out of date and since it has been used it could have had some bad gas go through it. Wire could corrode, etc.

Now, it wasn't running well when you shut it down so the problem was there already. What is the voltage for the tractor? 12v or 6v. Does is it frontmounted or sidmounted distributor? Does it have points or is it EI? If points, when was the last tune up done? What type of points were used, etc.

Simply, we need more info to troubleshoot, but a trip outside with your 7/16 wrench and old spark plug will help eliminate some potential problems.
 
" I shut it off and it won't start back up. "

There are easily a half dozen causes for that, but rather than guess, run the diagnostics & post back.
75 Tips
 
Codi, check your points and see if they have not sliped, mine was doing that last summer and we found the points had sliped and was nearly closed. James
 
Codi,

Next time you can, run it like you stole it. After the pre-start check of oil, gas, and coolant work it for an hour or more trying to force the issue to surface again and if it does, have your spark-plug and 7/16 wrench ready to go.
 
(quoted from post at 21:10:21 04/20/14) I walked back over to it after a while of it cooling off and it started right up.
Well of course it did! Until it gets warm again. ;)
Be prepared to do the recommended checks when it quits again.
A quick spark check is easy to do when it quits.
So is the gas flow if you have already taken the plug out so its not frozen in.
 
(quoted from post at 02:17:56 04/21/14) Codi,

Next time you can, run it like you stole it. After the pre-start check of oil, gas, and coolant work it for an hour or more trying to force the issue to surface again and if it does, have your spark-plug and 7/16 wrench ready to go.

Okay. I'll try it. We all understand that the tractor DID NOT quit, correct? I shut it off after I was done using it and got back on to move it and it wouldn't start back up.
 
" We all understand that the tractor DID NOT quit, correct? "

Yes.

But do you understand that it does not matter?

When it refused to re-start, you had a spark or fuel problem. Had you performed the checks immediately, you would have found the cause. Because, as Royse said....it will happen again.
75 Tips
 
(quoted from post at 21:17:55 04/20/14) I was mowing the back yard today, which had extemely thick grass and the 8N was [i:b1c5b07073]struggling go up the hills mowing. It would just bog down something awful[/i:b1c5b07073].

When you wrote that I took it to mean that the old girl was exhibiting problems before parking it and letting it sit.

BTW, I don't think I got what type of 8n it was. That effects the troubleshooting. Still, you need to check the gas and spark set-up if it acts up again.
 
"We all understand that the tractor DID NOT quit, correct?"

Maybe I should have said when it quits running correctly?
It's not fixed, it's just cooled off enough to run again.
What caused it could still be fuel or spark.
Isolating which it is would be my first step.
A side mount coil is not nearly as prone to failure as a front
mount, but that doesn't mean it's not possible.
We just need to walk through the steps to prove what it is.
Saves a ton of money in not needed new parts that way!
 
(quoted from post at 13:17:55 04/20/14) I was mowing the back yard today, which had extemely thick grass and the 8N was struggling go up the hills mowing. It would just bog down something awful. Then when I parked it to cool off before I cleaned it off, It would not start back up. It would hit every now and then but would not start. Is this a vapor lock? Or are the plugs shot?

While checking for spark at the time of no start/quit is always first on my list....and maintaining the points. (a side mount #1 trouble spot is an intermittent short in the insulator where the wire passes into the distributor or the copper strip it's attached to)

in this case it sounds like a fuel issue,
rust in the tank restricting the outlet.
screens plugged in the system somewhere.
dirty carb
needle valve not behaving, blocked, plugged, held open, leaking.
water

in your post define 'struggling' while mowing
stumbling, missing, ragged?
or is it truly a bog down?
A good running engine when overloaded, will just decrease rpms
slowly with no raggedness, coughing, etc...until it stops
(watch the end of tractor pulls...)
If it is ragged when working too hard...ya have a spark or fuel issue...if engine is good.
 
The engine was just rebuilt so I doubt that the engine itself. As far as bogging down, it would just keep struggling until it would die all together. I would clutch and hold the brakes and it would come back. I will trouble shoot the ignition. I guess maybe the points could have come out of adjustment but the points and condenser are only about three weeks old and have less than 3 hours on them. The only things that haven't been replaced in the past year in the ignition system are the plug wires and plugs.

On the fuel front:
It has a new sediment bowl and screen as well as a new screen leading into the carburetor. The carburetor is new as well. (all of these things were replaced last fall.)
 
(quoted from post at 22:50:59 04/20/14) Codi,

Don't be surprised if the diagnostic you several weeks ago is out of date and since it has been used it could have had some bad gas go through it. Wire could corrode, etc.

Now, it wasn't running well when you shut it down so the problem was there already. What is the voltage for the tractor? 12v or 6v. Does is it frontmounted or sidmounted distributor? Does it have points or is it EI? If points, when was the last tune up done? What type of points were used, etc.

Simply, we need more info to troubleshoot, but a trip outside with your 7/16 wrench and old spark plug will help eliminate some potential problems.

it is 6V . It has a side mount distributor and has points. The coil, points, condenser, distributor cap were replaced three weeks ago. As far as the type of points, I believe they were tisco brand? band I am not 100% sure
 
I am not about to declare victory and go home, but a rough running and underpowered engine are part of the problem, I could see that the points are a problem. Any lube on the rubbing block? .025 gap? Tisco points have a bad reputation around here. Standard Ignition's Blue Streak and Napa's Echlin are respected.

When mowing in that thick grass before yesterday, did the engine falter as it did yesterday?

As for the fuel, I would still do the check. What harm do you have in letting it run out the bottom of the carburetor for a minute or two? Open the valve like you would to run it and stick a large cup under the carb. and dump the gas back in the tank.
 

What sort or lube should I be running on the rubbing block and I hadn't had difficulty before yesterday.

And you are absolutely right, it doesn't hurt a thing to open up the valve on the carb and see what I get. :)
 
Even if the points are not the problem, and they may not be, you need the lube to keep the rubbing block from wearing down prematurely. Not any ole sort of lube will do, but there is a type specific to the rubbing block of the distributor. I have both, but am about finished with the NAPA lube and it has worked fine and will last a looooonnnnngggg time. Lube the block about once a year under normal use.

NAPA Part number:

ECH ML1

OR

Mallory Cam Lube Grease #26015
 
I had a situation years ago. In the hot summer while using the tractor very hard, it would bog down and quit on me. I could crank and crank on it and it would not start.

If I let it cool down about 20 minutes it would start up.

I finally checked the points and there was almost no gap. Set the points correctly and the problem cleared right up.
 
(quoted from post at 13:26:42 04/21/14)
What sort or lube should I be running on the rubbing block and I hadn't had difficulty before yesterday.

And you are absolutely right, it doesn't hurt a thing to open up the valve on the carb and see what I get. :)

I've heard people here say that they removed the plug on the carb and installed a brass pet cock valve to make testing fuel flow a lot easier.

Always thought that was a good idea but have never gotten around to doing it yet.
 
(quoted from post at 21:43:10 04/21/14) Even if the points are not the problem, and they may not be, you need the lube to keep the rubbing block from wearing down prematurely. Not any ole sort of lube will do, but there is a type specific to the rubbing block of the distributor. I have both, but am about finished with the NAPA lube and it has worked fine and will last a looooonnnnngggg time. Lube the block about once a year under normal use.

NAPA Part number:

ECH ML1

OR

Mallory Cam Lube Grease #26015

Okay thanks!

I just checked the point gap and it was dead on the money .25. I checked for spark at the plugs and they are firing a bright blue spark.

I pulled the plug out of the carb and let about a quart of gas flow out. The gas ran steady and free of debris. I put the plug back and started it and ran it for a while with no problem but sputters when not under a load.

BTW: the plugs were firing 1 big bright blue spark fallowed by a smaller blue spark. Is that normal?
 
OK, so it's not gas. You need to check that spark as soon as it starts acting up or stalls again.
 

It never did act up again today. Just the sputtering and it does that as soon as you start it.
 
Sputtering at start and through the run duration sounds like a maladjusted carburetor, or more likely, some trash in the carburetor. With a good spark and points properly gapped, that makes me think carburetor.

That said, with them being Tisco points, I could see them or the condenser being bad. (The condenser bad or the points fouled.) Just for grins, take a piece of a brown paperbag and clean the points. You can use a crisp, new dollar bill to accomplish the same thing. That might cause your poor running issue, but I bet it is in the carburetor.

If the carburetor comes off, then disassemble it, removing the main jet and needles. Take a can of carburetor cleaner to it. I would not soak it in cleaner at this point. The cleaner in a can and some compressed air might get everything cleared up.
 
(quoted from post at 04:00:07 04/22/14) Sputtering at start and through the run duration sounds like a maladjusted carburetor, or more likely, some trash in the carburetor. With a good spark and points properly gapped, that makes me think carburetor.

That said, with them being Tisco points, I could see them or the condenser being bad. (The condenser bad or the points fouled.) Just for grins, take a piece of a brown paperbag and clean the points. You can use a crisp, new dollar bill to accomplish the same thing. That might cause your poor running issue, but I bet it is in the carburetor.

If the carburetor comes off, then disassemble it, removing the main jet and needles. Take a can of carburetor cleaner to it. I would not soak it in cleaner at this point. The cleaner in a can and some compressed air might get everything cleared up.

It sputtered with a brand new carburater. The carb is new with less than 10 hours on it. Maladjust? Quite possibly. But I am not exactly comfortable adjusting it. I have tried before but I was never able to get it to a good idle point. (The recommended 400 rpm)

Would the fact that the plugs are firing a good once followed immediately by a smaller spark have anything to.do with it?
 
Sometimes a man has to know his limitations on spark. I know the basics and can troubleshoot, but I have not seen a two time spark before.

JMOR, Sounder, Bruce, what say you?

For the carburetor, I gave up on the low end idle and don't worry about it idling well at 400 rpm. As long as it runs strong and smooth at higher rpm I can live with the intermittent ping at 600 rpm.

I would not make a habit of fooling with the carburetor all the time but sometimes it does need adjustment and if you have not set it to your tractor since you bought it, it probably needs some fine tuning. On the main needle, I have seen 8n run from 1 1/8 out to 1 1/2 open. Smooth strong motor sound with power under load is what I search for. The idle adjustment is somewhere near +-1/4 open.
 

Like I said it has a good strong spark but there seems to be a much smaller spark between the strong spark. I am really not sure if that is supposed to happen. If not, I could see why there would be a sputter.
 

I just have a feeling it is a fuel issue related to new carb - might be flooding when used but then when you let it sit for a while it airs out and will start, or the plugs are wet with fuel - it will bog down and die with too much fuel just as much as not enough. Is the air filter clean? I had a problem with mine where it would start and run on the level just fine - slightest hill up or down would bog down sputter and die - was gas in float causing it to flood bad. Any fuel dripping from the bottom of the carb anywhere?

lee
 


PS - don't take any notice of the label 'tractor expert' under my name - I think that is related to the number of posts you make rather than any actual knowledge!!!!!!! :shock:
 
(quoted from post at 17:18:02 04/22/14)
I just have a feeling it is a fuel issue related to new carb - might be flooding when used but then when you let it sit for a while it airs out and will start, or the plugs are wet with fuel - it will bog down and die with too much fuel just as much as not enough. Is the air filter clean? I had a problem with mine where it would start and run on the level just fine - slightest hill up or down would bog down sputter and die - was gas in float causing it to flood bad. Any fuel dripping from the bottom of the carb anywhere?

lee

the only time it drips is when it wont start and I keep cranking it, then it floods. Air filter is clean the last time I checked
 
Codi,

Three fuel related questions: Do you drain the carburetor at the end of the day on the tractor, or do you leave gas in it? Also, how old is the gas in the tractor? Is it treated with stabilizers, and if so, which brand of stabilizer?
 
(quoted from post at 18:54:18 04/22/14) Codi,

Three fuel related questions: Do you drain the carburetor at the end of the day on the tractor, or do you leave gas in it? Also, how old is the gas in the tractor? Is it treated with stabilizers, and if so, which brand of stabilizer?

No I do not drain the carb at the end of the day. The gas is a couple days old and no stabilizers.
 
The gas should be fine then, but I would start to make a habit of draining the carburetor at the end of the day. Doing so has helped me halt the problems the ethanol fuel caused the guts of my carburetors. I doubt that will fix this issue, but it can help for the future.

If the gas sits more than a month, I would treat it with Starbrite or Seafoam for stabilizing. I am hesitant to recommend the red Stabil.
 
(quoted from post at 19:22:09 04/22/14) The gas should be fine then, but I would start to make a habit of draining the carburetor at the end of the day. Doing so has helped me halt the problems the ethanol fuel caused the guts of my carburetors. I doubt that will fix this issue, but it can help for the future.

If the gas sits more than a month, I would treat it with Starbrite or Seafoam for stabilizing. I am hesitant to recommend the red Stabil.


Okay...... I got the girl out and worked her pretty hard and then shut it off and tried to start it right back up with no luck. I checked the point first. Everything was good there. Then I pulled the plug out of the carb and the gas flow was good. Then I pulled a sparkie and checked for fire and all was good there.

Then I opened up the main valve a little on the carb and she finally fired right up with no issue. I guess the carb is a little out of wack. I know a guy here in town that will adjust it for me or at least show me how to do it.
 
For some 8n tractors, the restart after hard work is tricky. My 8n sidemount points and 6v would not start easy when hot until I got the tractor's carburetor right. Sounds like the carburetor needs a basic clean and adjustment.

Take it to the fellow in town, but have him give you some pointers on how to disassemble the thing and adjust it. As I wrote earlier, each 8n is a little different in how you set the carburetor's main needle. Some tractors like it lean, and others like it richer. Plus that, if you are in a cold area, or in elevation, that can affect it too.

Peruse this website for pointers and tips. Me, I like to leave the jets in the first time when cleaning it because it is a delicate operation. If the basic clean with jets in doesn't work, I will then remove the jets and soak it in carb dip for several days.

http://www.external_link.com/M_S_TSX_Carburetor.html
 
" I know a guy here in town that will adjust it for me or at least show me how to do it.'

C'mon CODI, you've been around here long enough to know how to adjust a carb.

Make sure the tractor is at operating temp; that usually takes 10 – 15 minutes at idle depending on ambient temp.

Both Ford and Marvel/Schebler (assuming you have a M/S carb ) say to set both the side-pointing idlemix and the down-pointing mainjet to 1-turn as a starting point. I set the down-pointing mainjet to 1-1/2 turns and don't fool w/ it until the final step.

Then adjust the side-pointing idlemix for fastest idle; not the smoothest idle. Next, adjust the behind the carb idle-speed set-screw for very slow 400-rpms idle. Do that idlemix adjust for maximum idle at least 3-times. Make sure that you turn the screws slowly, like 1/8 of a turn at a time & wait a second or two for the engine to catch up. Take your time!

Do it like this:

1. Adjust idle mix jet until RPM increases

2. Adjust idle-mix set screw until the engine
nearly stops (as slow as you can get it unless you have a tach that tells you 400 rpm)

Repeat steps 1 - 3 three times.

Remember the side-pointing idlemix is out for lean, in for rich.

If you do not have any problems inside the carb, it is easy to get the idle down to 350 - 400 rpms.

Your last step is to go back to the main jet. Remember, in for lean, out for rich. If you end up turning it OUT more than ½ turn for max power (remember, you already had it 1 ½ turns out) then stop right there because you have a dirty carb or a fuel problem.
75 Tips
 
(quoted from post at 23:05:16 04/22/14) " I know a guy here in town that will adjust it for me or at least show me how to do it.'

C'mon CODI, you've been around here long enough to know how to adjust a carb.

Make sure the tractor is at operating temp; that usually takes 10 – 15 minutes at idle depending on ambient temp.

Both Ford and Marvel/Schebler (assuming you have a M/S carb ) say to set both the side-pointing idlemix and the down-pointing mainjet to 1-turn as a starting point. I set the down-pointing mainjet to 1-1/2 turns and don't fool w/ it until the final step.

Then adjust the side-pointing idlemix for fastest idle; not the smoothest idle. Next, adjust the behind the carb idle-speed set-screw for very slow 400-rpms idle. Do that idlemix adjust for maximum idle at least 3-times. Make sure that you turn the screws slowly, like 1/8 of a turn at a time & wait a second or two for the engine to catch up. Take your time!

Do it like this:

1. Adjust idle mix jet until RPM increases

2. Adjust idle-mix set screw until the engine
nearly stops (as slow as you can get it unless you have a tach that tells you 400 rpm)

Repeat steps 1 - 3 three times.

Remember the side-pointing idlemix is out for lean, in for rich.

If you do not have any problems inside the carb, it is easy to get the idle down to 350 - 400 rpms.

Your last step is to go back to the main jet. Remember, in for lean, out for rich. If you end up turning it OUT more than ½ turn for max power (remember, you already had it 1 ½ turns out) then stop right there because you have a dirty carb or a fuel problem.
75 Tips

Thanks for the tips Bruce! I am unable to get it down to 400 because the link from the hand lever to the governor is too long and has to be shortened. The nuts on it were seized so I am soaking it in oil to free it up so I can get the RPMs where you say they should be.
 
Good advice from Bruce.

When starting hot, I have found that aside from the perfect carburetor, you might need to pop the choke open rather than hold it open. Also, I have found that some 8n start hot with the throttle half open while others are fully shut and it starts easiest at ~500 rpm when hot.

Compared to modern machinery an old railroad analogy seems appropriate. They said that when you worked on a steam engine you took 10 minutes to find the problem and a year to fix it. For the diesel engine it took a year to find the problem and 10 minutes to fix.

These 8ns make me think of the steam engines. They each have a personality and cadence slightly different from the next. A modern JD all sound and act alike as far as I am concerned. Admittedly, a better tractor and with upgrades over the N series, like the diesel is superior to the steam engine, but the N has a romance to me as compared to the modern tractor.
 

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