Still dealing with no start issue. 2N

[fordfan19422n]

Can't figure out what's going on with my tractor. It is a 2N with an 8N engine. Front mount distributor. The trouble first started with the engine dying after being in use. Tractor would then start after sitting for awhile. Determined no spark. I bought a tune up kit that included points, condenser, rotor, cap, and plugs. I got the tractor to run briefly. I also had to do a water pump replacement when I discovered a leak while working on the electrical system. After the water pump job, the tractor started and I was able to check to make sure the new pump didn't leak around the gasket. All was good with the pump. I drove the tractor around for a bit and then let it idle. It sounded like the engine was not firing on all cylinders. I throttled the tractor down and the engine died.
I have not been able to get the engine to start since. I pulled each plug and checked for spark and each plug had blue spark. I also disconnected the fuel line at the carb and there is good flow from the tank.
Now when I crank the engine over, all I get is a few seconds of cranking and then an exhaust back fire that sounds like a 12 gauge shotgun going off. So fuel is apparently getting in the exhaust before igniting.
Any ideas? I am about at my wits end.

 

[HarryVanderpool]

Anyone please correct me if I'm wrong, but an exhaust backfire that sounds like a 12 gauge shotgun going off can only be caused by a sticky valve (which also diminishes vacuum) or an ignition problem combined with an over rich condition. Check firing order and timing. Remove valve covers and observe each and every valve and lifter motion. Connect a volt-ohm-meter across your ignition switch. Turn the switch on and wiggle the key. Do you get constant continuity? When we were stupid kids, we used to shift down our cars in a tunnel and momentarily turn the key off and back on; KERR-POW!! I suspect firing order with the symptoms as described.

 

[HarryVanderpool]

Also, we are on our 2nd coil and 3rd ignition switch on our heavily utilized 2N since 1987.

 

[Eman85]

Back to basics, check spark with a spark tester. Remove plug in the bottom of the carburetor and do a fuel flow test with a pint jar and a timer. Remove spark plugs and do a compression test.
Loud bang in exhaust sounds like some things aren't happening at the right time. The fact that it ran fine, dies and is now doing this really doesn't add up. Any chance the spark plug wires `got mixed up and on the wrong plugs?

 

[fordfan19422n]

I will look into your recommendations and see if I can find anything.

 

[Jim L WA]

I hate to see you just throw parts at it, but your original symptoms are right in line with a bad coil. You are seeing spark at the plugs when the coil is cool, but after running a few minutes it breaks down and quits. Then like Eman85 said, check the firing order. It should be 1-2-4-3 ccw. Number one is at the front of the engine.
Let us know what you find.

 

[old]

I will look into your recommendations and see if I can find anything.

I agree with Jim good chance you have a bad coil. Common for a bad coil to work just fine for 30-60 minutes get hot and stop working

 

[Cliff (VA)]

The late great sparky Meister Dell had a few thoughts on this problem:

"There are 4-common runtime "issues" with the 4-nipple ignition system.
(1) runs fer about 1-min and quits; restarts innna"bout 10-mins; BAD condenser, NOT yer problem
(2) runs fer about 5-mins and quits; restarts innna"bout 10-mins; CLOGGED in-the-tank filter; NOT yer problem
(3) runs fer about 15-mins and quits; restarts innna"bout 30-mins; BAD weaksister ignition switch; ($10, cheap) NOT yer problem but could be
(4) runs fer about 1-hr and quits; restarts innna"bout 4-hrs or overnite cool down; BAD squarecan ignition coil; the internal insulative tars melt and short-out the windings; causing weak sparkies just as you complain. Unfortunately, the only "cure" is a NEW squarecan ignition coil.

Remember, both the original 6V square can coil and the modern 12V coil MUST have the "infamous ballast resistor" NO ARGUE!!! Without the ballast resistor the insulative tar will continue to melt ........Dell, yer self-appointed sparkie-meister"

Coils die because they overheat from too much current over time. Do you have the ballast resistor?

A ballast resistor has low resistance when cold and once it warms up the resistance goes up to limit the current. It keeps the coil from overheating and melting.

Source for Ballast Resistor

If you are running 12 volts with 6V coil you also need:

Source for Dropping Resistor

 

[fordfan19422n]

Yes, running 12 volts. Have the ( what looks to be) original resistor with the terminal stud and I replaced the other resistor with new one from NAPA. One other thing I noticed is that a small lamp mounted on the dash that I believe is supposed to excite the alternator no longer illuminates.

 

[old]

Yes, running 12 volts. Have the ( what looks to be) original resistor with the terminal stud and I replaced the other resistor with new one from NAPA. One other thing I noticed is that a small lamp mounted on the dash that I believe is supposed to excite the alternator no longer illuminates.

The charging system not working will not keep it from running as long as the battery has the volts needed to make spark. Run a wire from the ignition side of the battery as in non ground side to the coil. If it runs that way then the problem is from the coil back to the battery. If it still doesn't run problem is probably in the distributor

 

[Eman85]

Yes, running 12 volts. Have the ( what looks to be) original resistor with the terminal stud and I replaced the other resistor with new one from NAPA. One other thing I noticed is that a small lamp mounted on the dash that I believe is supposed to excite the alternator no longer illuminates.

Get it running, worry about that light later.

 

[fordfan19422n]

I will keep everyone posted on my progress with issue. The boss man has us working overtime so it will be a few days until I get back to the project. At least the OT pay will help with the money I've been throwing at this thing.

 

[fordfan19422n]

Ok, I found the source of the back firing. Plug wires 3 and 4 were wrong on the distributor. I still can't figure how it ran for a while like that before it died and wouldn't start and then backfire. I got the tractor to start. It took a few seconds of cranking and a couple sputters before she fired up. It ran for approximately 5 minutes and died. Now it's crank and crank with nothing to show. Don't have time for any more trouble shooting tonight.

 

[Eman85]

OK, since I guessed that one right, go and read my post #4 and do the tests.

 

[fordfan19422n]

I had a little time this afternoon so I was able to remove the plug from the carburetor bowl and do the fuel flow test. It took 2 minutes and 38 seconds to fill a pint. Is that acceptable?

 

[Jim L WA]

Don't forget, you may have a charging issue. Check the battery voltage with a meter. If it's too low it will quit like that. That 2 1/2 minutes to fill the pint jar is a bit slow, but may be acceptable for low engine speed with no load.
The next time it quits running like on Tuesday, check for a spark at a spark plug right away and see if the coil feels hot to touch.

 

[fordfan19422n]

Jim L WA,
Oh I have not forgotten about the ignition issues. Lol. Pretty soon it maybe Col (crying out loud). I was just following one of Eman85's recommended tests. I just wanted to make sure I didn't have two problems going on at once. I still believe the culprit is an electrical issue.

 

[Eman85]

A tad slow but if it flows steady like that for 2 min it will support the engine running. You're in an elite group of people that will actually do the fuel flow test. Go to the head of the class!

 

[fordfan19422n]

Well, I got her running again. For how long I don't know. I'm starting to lean towards it being the coil. I haven't been able to troubleshoot it for a few days. So today I started doing voltage checks and everything seemed to be checking out, but no start. I ran a jumper wire from the positive straight to coil. Meter registered battery voltage on coil top post. Still no start. I took the coil off and put the other coil I have on the tractor. Tractor starts. I get looking and some how I had put the old coil back on the tractor. The tractor has been idling for over a half hour now. My only concern is that the resistors are only knocking the voltage down to 9 volts at the coil. I put black lead on neg post of battery and red lead on coil top post and I get a reading of 9 volts going into a 6 volt coil with the tractor running. Do you think the coil will last very long being fed 3 volts over the limit? Any and all comments are welcome.

 

[Jim L WA]

Glad you got it running again. I'm not sure it the coil will stand up to 9 volts for along time, but I think it will. Others will chime in on that.