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Subject: No start 8N

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Mike Maiman    Posted 11-29-2022 at 15:07:27 [URL] [DELETE]        [Reply] [Email]  
  • No start 8N
  • I'm not on speaking terms with my 51 8N now for about 2 weeks. This engine has 5.4 hrs on a total rebuild and fired right off, however it became progressively harder and harder to start. Now absolutely nothing. Not even a cough or fart. Compression is around 115 psi at each cylinder. Carburetor was rebuilt and working fine. Gas in the tank, gas in the bowl and staring fluid in carb throat makes no difference. Ignition is new from the plugs to the distributor bushing. Hot spark at each plug. I've static timed this ignition using 3 different methods (2 from the How To section and 1 from the Ford operators manual). It definitely seems like there is no fire at the right time. This engine is not complicated but has me throwing in the towel. Help on how to proceed next would be most appreciated. Thanks

    Bruce(OR)    Posted 12-03-2022 at 00:06:51 [URL] [DELETE]        [Reply] [No Email]  
  • Re: No start 8N
  • So you went through everything and found flooded plugs. . . No?

    Ed Gooding (VA)    Posted 12-03-2022 at 05:38:24 [URL] [DELETE]        [Reply] [Email]  
  • Re: No start 8N
  • Bruce(VA)    Posted 12-01-2022 at 07:17:56 [URL] [DELETE]        [Reply] [Email]  
  • Re: No start 8N
  • You have two problems.

    First, if it is a 12v round coil w/ 3.25 ohms internal resistance, it does not need any ballast resistor. Jump or remove it as Ed said.

    Next, you set the static timing incorrectly, apparently more than once. Its 4*, NOT 0*.

    Start over.

    Remove the #1 spark plug. (removing all of them makes the job a bit easier) Ignition off, place your thumb over the #1 spark plug hole and crank slowly until compression is felt. Continue to crank the engine until you see the timing mark, 0* (top dead center) on the flywheel through the timing hole in the right side of the bell housing. Use chalk on the flywheel to exactly align the 4 degree mark with the pointer. Hold the distributor beside the engine. W/ the distributor oiler at the 7 o'clock position & the stud at 9 o'clock, turn the rotor until it points roughly at the right front head bolt. (close counts) Now insert the distributor. Rotate the distributor housing counter clockwise until the points are closed. Put the cap on & double check the plug wires, 1-2-4-3, CCW. Then, remove the primary wire from the side of the distributor (or at the coil, whichever is easier) Put one lead of your VOM (set on resistance) on the stud on the side of the distributor & the other on the block or other good ground. Slowly turn the distributor. The needle will move as the points close & then open. Find the exact spot just as the points open & then tighten down the distributor.

    Now check your work (and the dynamic timing) w/ a light.

    If it won't idle below 500 rpm (400 is better) don't bother w/ a light.

    If it idles ok, make 3 marks w/ chalk or white paint on the flywheel:

    4*
    10*
    17*

    Start the engine.

    At idle, the light should flash & the marker should line up exactly at 4* if you did the static timing correctly.

    If not, loosen the distributor & turn it until the marks line up. It should take very little adjustment.

    Once you've got that done, increase the engine speed to 1200 rpms. The light should flash & the marker should line up w/ the 10* mark. Then, increase the rpms to 2000 & look for the marker to align w/ the 17* mark.

    Close counts on the advanced timing. A degree or 2 either way is ok. But, no movement or 5* or more off means you have an advance weight problem. You don't adjust the distributor to fix that.


    deanostoybox    Posted 11-30-2022 at 20:57:00 [URL] [DELETE]        [Reply] [No Email]  
  • Re: No start 8N
  • A couple of things I can think of:

    IF you are finding TDC for #1 by the thumb over spark plug hole method while spinning the 6V starter with 12V AND all the plugs are out, it is possible the engine is coasting past TDC far enough that the next set of timing marks comes up for 2 and 3 instead of the marks for 1 and 4.

    Another possibility might be the manifold has eroded between the intake and exhaust and the hole has gotten big enough that enough air is getting into the exhaust to prevent enough fuel from getting to the cylinders.

    Wild guesses both.

    deanostoybox    Posted 11-30-2022 at 20:59:12 [URL] [DELETE]        [Reply] [No Email]  
  • Re: No start 8N
  • that enough air is getting into the intake from the exhaust

    Jack - Iowa    Posted 11-30-2022 at 07:41:32 [URL] [DELETE]        [Reply] [No Email]  
  • Re: No start 8N
  • I fought a similar situation on my 860 for longer than I care to admit. Finally a member here wrote: If it does not fire on starter fluid, you have an ignition problem.

    One of my problems was the engine had not been assembled correctly! Timing marks meant nothing. Resorted to finding compression on #1 and setting distributor on that. Final timing by ear as we did before we could afford timing lights.

    Good Luck,

    Jack - Iowa

    Farmer Brown    Posted 11-30-2022 at 04:55:40 [URL] [DELETE]        [Reply] [No Email]  
  • Re: No start 8N
  • Sorry, ignore my previous post regarding compression. Didn't see that you already checked that.

    Are you sure the distributor and plug wires are properly installed? Is the spark which is present at the plugs of sufficient intensity. The spark should be able to jump a 1/4 inch gap if the ignition is good.

    Farmer Brown    Posted 11-30-2022 at 04:48:53 [URL] [DELETE]        [Reply] [No Email]  
  • Re: No start 8N
  • If you are sure you have hot spark at the plugs and fuel being delivered, I would check compression on all cylinders.

    Bruce(OR)    Posted 11-29-2022 at 18:45:36 [URL] [DELETE]        [Reply] [No Email]  
  • Re: No start 8N
  • Folks a lot smarter than I, should be along shortly.
    Harder and harder to start.
    Gas in the bowl. That's nice. Pull the bottom plug out of the carb yet to check flow through the carby?
    No? Pull the brass fitting at the carb and see if it's plugged.
    Points closed up on you? Gap is what? Point gap effects timing.
    Pull the #1 plug.
    Crank the engine around until you start to get comp on the cylinder.
    Now turn the engine by hand and line up your timing marks.
    Pop the dist cap. Is the rotor aimed at #1 inside the cap?
    Peace be with you.

    Mike Maiman    Posted 11-29-2022 at 22:13:16 [URL] [DELETE]        [Reply] [Email]  
  • Re: No start 8N
  • Gas flows through the bowl with the plug out. The in carb filter screen is clean. Starting fluid has no affect.
    Point gap is .025" at every distributor cam lobe.
    Timing marks at 0 deg. TDC and rotor lines up with #1 terminal in cap.
    I've checked these several times. I'm missing something that has to be very simple. But what?

    Bruce(OR)    Posted 12-01-2022 at 14:44:23 [URL] [DELETE]        [Reply] [No Email]  
  • Re: No start 8N
  • Pull and dry the plugs.
    If you have any spark, with ether, it should at least bark.
    No bark, even with timing fairly whacked, it should at least bark.
    unless the plugs are nicely flooded.

    Ed Gooding (VA)    Posted 11-30-2022 at 07:02:36 [URL] [DELETE]        [Reply] [Email]  
  • Re: No start 8N
  • Mike, are you still 6-volt, or did you convert when doing the other work?

    Mike Maiman    Posted 11-30-2022 at 09:07:47 [URL] [DELETE]        [Reply] [Email]  
  • Re: No start 8N
  • 12 volt. 1/4 long blue spark at all plug wires using spark tester.

    Ed Gooding (VA)    Posted 11-30-2022 at 09:26:09 [URL] [DELETE]        [Reply] [Email]  
  • Re: No start 8N
  • Did you convert to 12v from a kit? Did you upgrade to a 12v coil or do you still have your 6v coil?

    Mike Maiman    Posted 11-30-2022 at 18:24:44 [URL] [DELETE]        [Reply] [Email]  
  • Re: No start 8N
  • Ed,
    No kit. I used a Delco 12SI 3 wire alternator with an exciter wire. The coil is a new
    Blue Streak 12v with an external ballast resistor.

    Ed Gooding (VA)    Posted 11-30-2022 at 18:47:51 [URL] [DELETE]        [Reply] [Email]  
  • Re: No start 8N
  • The resistor may be your issue. Can you remove it or jump around it to see if she will start?

    Mike Maiman    Posted 12-01-2022 at 16:22:20 [URL] [DELETE]        [Reply] [Email]  
  • Re: No start 8N
  • I jumped around the resister and still no start. It's really a mystery.

    Ed Gooding (VA)    Posted 12-02-2022 at 14:07:23 [URL] [DELETE]        [Reply] [Email]  
  • Re: No start 8N
  • This is the timing procedure from the Ford Tractor Dealer Mechanic Training Manual that is in our How-To's library:

    Ed Gooding (VA)    Posted 12-02-2022 at 13:08:38 [URL] [DELETE]        [Reply] [Email]  
  • Re: No start 8N
  • Well, then I would follow Bruce Haynes' (VA) advice about setting your ignition timing from scratch.

    To recap: You have fuel that flows through the bowl via the drain plug, you get a 1/4" inch blue spark on all 4 cylinders, and you have bragging rights compression. Those are the three components you need for your engine to run. What's mystifying about this is that you say it did start initially but got harder and harder to start until it wouldn't. Makes me somewhat suspicious that your issue may be in your distributor. Do you have access to another, known good one to swap in?

    Mike Maiman    Posted 12-02-2022 at 18:00:38 [URL] [DELETE]        [Reply] [Email]  
  • Re: No start 8N
  • All along I felt it had to be spark related. I've been all over that ignition system and timing like a pit bull on a pork chop and couldn't find a thing wrong. Today I decided to put the old distributor cap and rotor back on and bingo it fired right off. What a fiasco!
    Thanks to all of you for offering advice. It's nice to know that there is a community out there that is willing to share knowledge.
    Press on!

    Steve Dabrowski    Posted 12-02-2022 at 18:38:09 [URL] [DELETE]        [Reply] [No Email]  
  • Re: No start 8N
  • I've been following this all along and had no concrete suggestions. I wondered if the camshaft gear might have been slipping (thinking a pressed on gear like my early 9N has) but the later tractors all have bolt on cam gears so made no sense. Would like to see if changing only the rotor does the trick-that would make sense that it might be cheap plastic junk and wore immediately after installed.

    I can only imagine from my periodic frustrations with my 48 occasionally not wanting to start when it normally catches on the first crank and finding no good reason for it, what you must have been going through. Glad you found it.

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