No 8N power

[Anonymous-0]

After eliminating some ignition problems, my early 8N still is hard to start and when it runs, has no power. Compression is good (close to 150 psi on all 4). After testing, I found that she's running only on #1 cylinder. I can take 2,3 and 4 wires out and the RPM does not change. Is there a simple check I can do before I go to the valves?
I would love to hear some wisdom from ya'll

 

[Colin King]

When you say "early 8N," does that mean that it has a front mount distributor?

Is it 6 volts or 12 volts?

150psi on the cylinders is [i:654c4848f0]really[/i:654c4848f0] high. 120psi factory spec would be expected on a new or rebuilt engine.

What ignition problems did you deal with? What components did you replace?

Have you checked for spark on all other cylinders?

Colin, MN

 

[Bruce (VA)]

In addition to answering Colin's questions, you do need to do that compression check over. No way it's got 150 psi. Tip # 46 (below) will help. And, if it's only firing on #1, you still have some pretty serious ignition problems.
50 Tips

 

[souNdguy]

Uh.. With that many cyls not fireing.. I'd check fire order first.. then I'd check cam surface inthe distrib to see if all ears but one are worn down! ( check spark on the lines not fireing first.. )

Soundguy

 

[A. Bohemian]

If it was truly hitting on only one cylinder, the engine probably would not run. The Ford flathead four (and most other simple four cylinder engines) will generally run on two cylinders, but not on only one.

I think soundguy is probably right here; check the firing order. 1-2-4-3 with number one at the FRONT.

 

[A. Bohemian]

Sorry. I meant, "The Ford flat-head four will run on two cylinders, but generally won't run on only one."

 

[MauNC]

Thanks to all you folks for the reply. I will try to expand and answer all your questions.
I have a 49' 8N, 12V system w/front mount distributor, electronic ignition, late model governor w/tachometer.
Installed new plugs, new plug wires (resistor type to go with the electronic ignition), new distributor cap and new 12V, 2.5 ohms coil. Voltage to coil is 8-9V @ 1200 RPM. The distributor seems to be in good mechanical condition with no play. Get a strong (3/16") blue spark on all 4 with tester and a good spark on all the new plugs also. The 1-2-4-3 wiring is correct.

What I meant when I said that it is running on one cylinder only, is this: I take wire plugs 2-3-4 out, one at a time. When I do this, the engine doesn't seem to change the RPM, but if I take #1 out, it dies. I tried this test again today, but with 2-3 and 4 totally disconnected from the plug, guess what? It runs. Not only that, it starts with one cylinder, (of course if I put in gear, It dies). Also I checked the plugs after I stop the engine, and 1 and 2 are dry and 3 and 4 are wet.
The electronic ignition has been on the tractor for about a year with out any problems. if I get a good spark on all cylinders, I don't know how to single out the electronic ignition . As far as the compression test, I don't know if I was off or the tester was off. In any case the compression was even on all four, well above 100 psi. I can't retake it today because the hood is back in. I have to get me one of those elbow adapters.

I hope I have given enough detailed description of my problem for you gurus to make any sense. I always appreciate your help.

MauNC

 

[souNdguy]

Hmm... you get fire on the plugs 2-3-4 with them off the tractor.. AND you say you have compression of 100+ psi on those cyls... hmm

fire + air+ fuel+compression at the right time = running.

I'd want to think it was timed good if it starts on 1 cyl.

My guess is compression, or fouled plugs that aren't fireing under compression.

By the way.. just because you have an electronic ignition.. you don't need the resistor wires. r-wires are for modern high energy ignition systems. Your electroninc ignition is noting more than a transistore making and breaking contact to the coil vs a set of points. Makes a bit less RFI/EMI due to not having breakers.. but that's about it.. No HEI ...etc..

Soundguy

 

[MauNC]

I will take the hat off the tractor in the next few days. I use a small lawnmower gas tank that I adapt when the hood is out. At this time I will retake the compression test. (I have to have it off anyway because I need to replace a crankshaft pulley for a later loader installation).
Just for the sake of discussion, can some water go into the valves to kill the firing? If this is a possibility, would my next step be to remove the head and check the gasket and/or whatever? I never got into the engine yet, but I guess there is a first time for everything. What you think?

MauNC

 

[souNdguy]

Your comp check will check the head gasket.

Soundguy