# 8N Gas Flow Problem



## Glen640 (Jul 11, 2014)

About a year ago, on my Ford 8N, I drained the gas tank (by running the engine until it went dry), removed the hood and gas tank to get at the radiator and change axles. Stuff came up and I didn't get back to installing the gas tank until now. The bowl was half empty but shaking the tractor got gas to fill up the bowl. The tractor wouldn't start. After removing the gas line at the bowl, I can see that no gas is flowing to the carburetor. Any thoughts on why I am not getting gas to the line? This was a very reliable starting tractor prior to taking it apart.


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## pogobill (Jan 31, 2012)

Sounds like it might be the screen in the float bowl, or the screen that goes up into the bottom of the gas tank is clogged. 









Do you get a flow if you loosen the gas cap? Maybe the tank isn't venting properly. These things usually need a good bit of fuel in the tank to get going and seeing as they are gravity feed, they may not work well with an inline fuel filter.


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## sixbales (May 18, 2011)

Bill's diagram puts you on the right track. There may also be a fuel screen in the inlet elbow of the carburetor.

I had a spider build a nest in an open fuel line many years ago. Mud daubers can also build nests in open lines. Blow out the line with compressed air.


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## VFord8N (Aug 18, 2013)

Glen640 said:


> About a year ago, on my Ford 8N, I drained the gas tank (by running the engine until it went dry), removed the hood and gas tank to get at the radiator and change axles. Stuff came up and I didn't get back to installing the gas tank until now. The bowl was half empty but shaking the tractor got gas to fill up the bowl. The tractor wouldn't start. After removing the gas line at the bowl, I can see that no gas is flowing to the carburetor. Any thoughts on why I am not getting gas to the line? This was a very reliable starting tractor prior to taking it apart.


My 8N has also been finicky even with a new tank, screens, bowls and lines etc. Definitely follow the 2 pieces of earlier advice on cleaning screens, the fact you ran it dry probably dislodged dirt and clogged somewhere in your system. I have found that keeping my tank very full with gas has alleviated many of my starting problems; but that is only after you are ensured of unimpeded gas flow to the bowl and then to the carb.


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## Glen640 (Jul 11, 2014)

Thanks to all. Very helpful. I followed Bill's suggestions pretty much in order and none changed the outcome until I added more gas. I now have gas flowing abundantly. Unfortunately for me, I must have had another problem, either when I shut it down way back when or was created during the lengthy sit. Still won't start. So now not sure where to go next.


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## deerhide (Oct 20, 2016)

Is there gas going into the intake manifold? Spin it over with the choke fully closed; gas should drip out of the carb intake....If there is gas the next step is check for spark; take a plug wire off of a spark plug, hold the end close, 1/8 inch, to the plug top (or another place where there is bare metal)and with the key on spin it over...there should be a visible spark. No spark? go to the distributor...If you have gas and spark check compression.


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## VFord8N (Aug 18, 2013)

VFord8N said:


> My 8N has also been finicky even with a new tank, screens, bowls and lines etc. Definitely follow the 2 pieces of earlier advice on cleaning screens, the fact you ran it dry probably dislodged dirt and clogged somewhere in your system. I have found that keeping my tank very full with gas has alleviated many of my starting problems; but that is only after you are ensured of unimpeded gas flow to the bowl and then to the carb.


Do follow the suggestion of the manifold and spark path. I was in a similar predicament earlier. Also, remember that today's gas only has a 6 month life span, maybe add some stablilizer/cleaner such as "startron"; it helped me. I'm intrigued by you story as my experience was similar after I changed my gas tank, cleaned the carb and re-did the points and my starting problems began.


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## Glen640 (Jul 11, 2014)

Not sure I understand the "Is there gas going into the intake manifold? Spin it over with the choke fully closed; gas should drip out of the carb intake". When I loosen the nut at the carb end of the gas line, gas runs out. Is this not a sufficient test of gas flow? 

For the spark test, I removed the plug, attached the plug wire, and held the gapped end close to the manifold. Is that the same as what you described?


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## pogobill (Jan 31, 2012)

Sounds like you passed the spark testing procedure Glen. Now are the plugs firing at the correct time? Did you by chance remove and replace the plug wires possibly mixing up the firing order? When was the last time you put a drop of oil in the oil cup on the side of the distributor to allow the spark advance to work? Full Choke and cranking it without starting should at least soak your spark plugs with gas. At least you'll know that gas is actually getting into the engine, albeit, causing it to flood! Are the spark plugs clean / new / gapped properly? Perhaps if all else fails, can you check to see what kind of compression you're getting as deerhide suggested? Pardon my ramblings!! How about the linkage to the governor from the carb? I had a stuck linkage on my Cockshutt and once freed, the tractor fired right up.


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## RC Wells (Dec 26, 2008)

Shut off the fuel then remove the plug at the bottom of the carburetor. Turn the fuel back on and look for fuel to drain out in a catch container.

No fuel out, then you either have a clogged filter on the carburetor inlet, some have a screen in the fitting that screws into the carb, or a clogged or stuck carburetor needle valve.


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## deerhide (Oct 20, 2016)

Glen640 said:


> Not sure I understand the "Is there gas going into the intake manifold? Spin it over with the choke fully closed; gas should drip out of the carb intake". When I loosen the nut at the carb end of the gas line, gas runs out. Is this not a sufficient test of gas flow?
> 
> For the spark test, I removed the plug, attached the plug wire, and held the gapped end close to the manifold. Is that the same as what you described?


No, if you put the plug back on the wire you need to touch the big metal end to a suitable ground, the manifold is good, just can't be painted. Hopefully you will see a spark.
Not really the proper test for gas; by loosening the gas line at the carb you now know that gas is getting TO the carb, but you need to know if gas is getting THrough the carb and to the combustion chamber. The carb is 99% likely to be an updraft Marvel/Shebler ?? and they can be stubborn. Push the choke knob in and try squirting or 'sloshing' some gas right into the carb, then pull out the choke knob and try starting it.(fire extinguisher handy?) If it starts or even 'kicks' I would say you need to take the carb off, take it apart and clean it, I used to use lacquer thinner. Every screw you take out remember how many turns it took and put it back in the same number of turns. You may need adjustments but do that for now. They are a simple carb and parts for them or rebuilt ones are available, but not cheap.


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## Glen640 (Jul 11, 2014)

Hey guys. Thanks for sticking with me this far and for all your help. If nothing else, I am learning something.

I have done, and in some cases, re-done all of your suggestions except the two that I didn’t understand. I will list them first.

1) “Spin it over with the choke fully closed; gas should drip out of the carb intake.” What did you mean buy the carb intake. To me that would be where the gas line comes into the carb but that can’t be since that is screwed in and can’t leak.

2) “…. take a plug wire off of a spark plug, hold the end close, 1/8 inch, to the plug top … and with the key on spin it over…there should be a visible spark”. I’m confused here. The plug wire end metal cap, that covers the top end of the plug, is recessed an inch from the end of the plug wire end insulator and the exterior of that cap is insulated. So do I hold the metal cap 1/8” from the plug top or hold the bottom of the insulator 1/8” from the plug top. If the former, where is the spark going to show and if the latter, it seems unlikely that the spark could jump the 1 inch from metal cap to plug top. What am I not understanding.

I would like to do these tests also before concluding anything but I need help in figuring out the things I don’t understand.

Here’s what I have done so far

1) Gas comes into the carb from the bowl

2) When I loosen the screw under the carb, gas comes out. More comes out when I turn the knob at the bowl

3) When I crank the engine with choke in and ignition off, the compression side of the plugs are not getting wet

4) I put some 3-in-one oil (not motor oil) in the distributor oil cup

5) If the governor is under the distributor, then the linkage seems good to me (although I don’t know what the ease of movement is supposed to be)

6) When I tested spark by removing the plug, wire attached, grounding the base against the bare manifold, and cranking the engine with ignition on, there was no spark

7) The plugs are old but gapped and the electrode area looks clean. That is consistent with how well it ran and how easily it started before I shut her down. I will replace plugs next time I go to town but I have rarely found this to solve my problems if the noted conditions were similar

8) I didn’t try the suggestion that involved a fire extinguisher

Repeating, I would like to try the two suggestions I didn’t understand if someone wants to fill in my blanks. 
Sorry for the length.


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## deerhide (Oct 20, 2016)

1.You need to determine that gas is getting into the combustion chamber. I referred to the carb intake; I should of said the carb Air intake give it a good squirt. If it offers to run or even gives a 'chug' or two your carb is plugged or stuck somewhere.
2.Take a plug wire off of the plug and hold the end in your fingers, rest your hand on a good ground, then, with the key in the on position push the starter button, if you have good spark you will definitely feel it, if it is a weak spark you will hardly feel it and of course if you don't feel any electricity you have no spark to the plug. It won't electrocute you but if you don't have your hand that has the plug wire in it on a good grounding place your fingers on the starter button will be the ground. That would make you jump. Clean plugs, no matter how old, usually will spark. I've had and used at least a dozen old Fords, including a 'late' (with side distributor), 8N I took a piston and rod out of and run it on 3 cylinders so we could finish haying. It had broken a sleeve and we had to order it.


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## pogobill (Jan 31, 2012)

The spark plug test seems to be as you explained in greater detail in the above post. Remove a
Spark plug, hook the spark plug wire to it again and ground the threaded portion to the engine as shown below. Try and start the engine and you should see a spark jump the gap as it should. Make sure you are not doing it in bright sunlight, the darker the area, the easier to see the spark. Spark should be a nice blue as in the picture.










You could also get one of these to throw in your tool box to make life easier when testing plugs. Set the gap on the gauge and then remove the sparkplug wire, attach the alligator clip to the top of the spark plug, hook the spark plug wire to the other end. crank the engine over and you should see a spark in the window.









Should mention as well, that the spark should only jump the purposed gap and not be jumping all over the base of the spark plug.
If there is no spark, check for a loose connection to and from the coil. Could be as simple as a loose coil wire from the coil to the distributor! Check all the spark plug wires while you are at it.
Perhaps the coil needs replacing. Have you looked inside the distributor under the cap? You can pop the cap off and see if your points are burnt or perhaps stuck together.
Do you have a manual for your tractor?


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## deerhide (Oct 20, 2016)

That is a great illustration! Neat tool too.


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## Glen640 (Jul 11, 2014)

Finally did the carb air intake test. Gas came out the air intake which is good but the spark plug electrodes are still dry. I noted too that gas was also leaking out of what I would not have guessed was an opening on the underside of the carb. It is just forward of the plug at the bottom rear of the carb. Is that some sort of an overflow weep hole?


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## pogobill (Jan 31, 2012)

Hmm... stuck float? Give the carb float bowl a tap with a mallet or a hammer handle.... be careful not to whack it hard enough to damage it. see if the leak on the bottom of the carb stops. You could be in store for a carb cleaning or a rebuild.
Do you have a manual for your tractor?


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## Glen640 (Jul 11, 2014)

I do have an 8N manual: Ford Shop Manual FO-4.


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## biker48 (Oct 19, 2014)

Glen640 said:


> Finally did the carb air intake test. Gas came out the air intake which is good but the spark plug electrodes are still dry. I noted too that gas was also leaking out of what I would not have guessed was an opening on the underside of the carb. It is just forward of the plug at the bottom rear of the carb. Is that some sort of an overflow weep hole?


Yes to your Question. Prevents too much build up of gas in the air chamber. If you do not have spark at the plug wire as was previously suggested, you need to concentrate on your distributor points , condensor , rotor , cap and the coil. Once you have sparks to the plugs and it does not want to fire , take one plug out and pour a thimble full of fuel in and replace plug. Try it. If it fires and quits and still won,t start check for a chance that mice have plugged your exhaust system. Happened to me. Easy check. Just unhook exhaust at manifold. Then try starting.


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## deerhide (Oct 20, 2016)

Wisht I was there to help


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## pogobill (Jan 31, 2012)

biker48 said:


> If it fires and quits and still won,t start check for a chance that mice have plugged your exhaust system. Happened to me. Easy check. Just unhook exhaust at manifold. Then try starting.


Good suggestion! Way out there, but every inexpensive fix is a good one. My 8N gave me a bit of grief last year and would not start. I couldn't, for the life of me. figure it out. I accidentally leaned on the exhaust pipe while trying to start it, opened the flange connection as a result, and the tractor fired right up! Bought a complete exhaust pipe/muffler for it for like $39.00.


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## Glen640 (Jul 11, 2014)

Wish you were too. You would have had this thing hummin by now.


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## Glen640 (Jul 11, 2014)

In case you are still receiving this thread and have an interest in how it turned out, I write.

Although I have yet to have a situation where new plugs solved my problem, I decided to go ahead and replace them. Also, I wanted to try Deerhide’s suggestion to put some gas in the plug hole. I ended up trying both at the same time. I put gas in one of the cylinders after changing all the plugs and tried to start it. Nothing. Was sure then that it must be the lack of spark. Decided to put gas in another cylinder before giving up. Pulled the choke, hit the starter and … voom, started right up. Runs great.

So to all you guys who stayed with me to offer advice and suggestions to help me solve this … THANK YOU. All the things you said I tried and I am sure they all helped lead up to the successful conclusion. Couldn’t have done it without you.


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## deerhide (Oct 20, 2016)

I think it was biker48 that suggested the thimbleful of gas into the plug hole. I'm glad u got it going they are a great old machine...


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