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Subject: ford 9n

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David    Posted 06-27-2018 at 16:31:27 [URL] [DELETE]        [Reply] [Email]  
  • ford 9n
  • I have a 1942 9n just recently acquired it has been running great up till today now it ran then seemed as though it was starving for fuel and just quit running.IO got it started again but it doesn't last long and dies again.Anyone have any ideas on what could be happening?

    Bruce (VA)    Posted 06-27-2018 at 18:48:42 [URL] [DELETE]        [Reply] [Email]  
  • Re: ford 9n
  • It is important for you to tell us if your tractor has a 6 volt or 12 volt electrical system . 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.

    As soon as it stops running, not 5 minutes later, 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 1/4Ē gap, you probably donít have a spark problem. If it wonít jump the ľĒ gap, you have a spark problem. If the ammeter needle shows a constant discharge, or doesnít 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 doesnít 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 itís a dribble, or runs for 5 seconds & stops, or none at all, you have solved half the problem: itís 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 itís 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 doesnít work, tap the carb bowl w/ a hammer handle in case the float is sticking closed. (donít whack it w/ the head of the hammer; you can crack the bowl). If you still donít 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. (donít 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! Thatís why removing the 7/16Ē 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 ľĒ in the open air. Remember, itís 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 wonít shock the snot out of you like an old plug might!

    Post back with results or more questions.

    *If you donít own a spark checker w/ an adjustable gap, buy one. In the meantime, an old spark plug w/ the gap opened to at least ľĒ will work. Ground it to a rust & paint free spot on the engine turn the key on & look for a spark.

    BlasterStumps    Posted 06-27-2018 at 17:01:43 [URL] [DELETE]        [Reply] [Email]  
  • Re: ford 9n
  • possibly the fuel screen(s) is/are plugging. Could even be a plugged vent for the gas tank. Not sure if the cap is vented but think the tank is. Loosen the cap.

    BlasterStumps    Posted 06-27-2018 at 17:10:12 [URL] [DELETE]        [Reply] [Email]  
  • Re: ford 9n
  • Do you have a manual for the tractor?

    There should be 3 screens. One in tank, one in sediment bowl and one at inlet of carb. I believe that is correct for a 9n.

    David    Posted 06-27-2018 at 19:20:01 [URL] [DELETE]        [Reply] [Email]  
  • Re: ford 9n
  • Thanks for the tips
    yes its a 6 volt system
    just by the way it sounds when I had the problem
    it would seem fuel related
    I will check and clean all the screens when I go back to the tractor tomorrow
    again thanks very much for the info its all new to me

    Tim Daley(MI)    Posted 06-28-2018 at 04:48:16 [URL] [DELETE]        [Reply] [No Email]  
  • Re: ford 9n
  • David-
    First, don't assume just because you have a 6-Volt battery installed on your tractor that the wiring is correct as the original 6V/POS GRN system. Also, how old is the battery and does it maintain a full charge under load? Simply charging it does not mean it is good. Your local starter/alternator shop can bench test it for free usually. We have many self-help and D-I-Y documents in our HOW-TO's forum -click on it in the top red MENU bar at the top of our home page. Under ELECTRICAL, scroll down to "WIRING PICTOGRAMS by JMOR" to see all the correct ways to wire these old N's whether 6V/POS GRN or a 12V/NEG GRN switch over. Download a copy for reference. There is a lot more to just having a 6-Volt battery. Find your model and verify it confirms exactly what you have, Next step is to test for fuel flow BEFORE you pull Sediment Bulb to replace/clean screens. With engine COLD, when you remove the carb drain plug on the bottom, then open Sediment Bulb Valve 2 Full Turns, see Bruce's Tips, you are checking to see if the carb is obstructing fuel flow. You can then remove the fuel line from carb inlet port at the brass elbow, open 2 turns and observe if fuel flows steady from the Bulb. If not, obstruction is in the Bulb, possibly screens and/or unit plugged. Often flakes of rust and dirt get trapped in the Bulb inlet port and cause obstruction. Gas must be drained from tank first before removing Bulb assembly. Do the Fuel Flow Test before doing any part replacement. Once fuel flow is correct, you will move on to the spark test. As an N-Series Tractor owner, many of us highly recommend that you invest in originals or copies of the essential manuals in order to better understand your tractor.




    Tim Daley(MI)

    David    Posted 06-28-2018 at 12:43:38 [URL] [DELETE]        [Reply] [Email]  
  • Re: ford 9n
  • thanks to all
    I drained a cup or so out of the bottom of the carb and
    she fired up and ran beautifully
    must have been some sediment of something in there
    works great now

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