Kaboom

Hi guys.
Greetings from WI.!
I had my 41 9n out yesterday to move some firewood. It was running well for about 10 minutes but then started running rough and backfiring through the exhaust.
Fuel problem?
Thanks
Pike

pikewi ,Check under the distributor cap for moisture (melting snow or water).

Most likely ignition.

Check points, cap, rotor and wires.

Dean

You never said if you came back later and tried to start it. That will help diagnose the problem.

No i didn't. I hope to get back to it tomorrow.
Thanks
Pike

Howdy Pike;
I can just hear yer Dad....(if he were still with us, God Bless his sole).........BOY, just get with the program, and fix the Dang thing!!!!!!!!!!!!!! :lol: :shock: :lol:

Gary

Not fuel, electrical. Check firing order: 1,2,4,3 CCW. Points or internal ignition shorted in distributor. Any electrical short can cause back-firing. I'd start with the wiring. Verify all is correct whether if 6V or 12VV but 12V switch over jobs by fellas usually cause more negative issues. Get your ESSENTIAL MANUALS out and start tracing wires and don't just go by wire colors, use a VOM to test continuity. If you have a 12V setup seek a download of "WIRING PICTOGRAMS" by JMOR. You won't find any original FORD 12V diagrams on N-Series tractors because they never used 12V, no need to, and this no need for a diagram. There are but less than a handful of correct ways to wire an N for 12V and hundreds of incorrect ways.


FORD 9N/2N ESSENTIAL OWNER/OPERATOR/PARTS/SERVICE MANUALS:


Tim Daley(MI)

Well, I will differ a bit from the general consensus here and suggest fuel issues. You say it was running fine for 10 minutes, that eliminates the suggestion your firing order is off (unless the plugs swapped around by themselves during use). Backfires are usually caused by excessive unburned fuel igniting in the exhaust from not being burned in the cylinder or, igniting at the wrong time in the cylinder. The first scenario is usually an air to fuel ratio issue, the later is usually a timing or ignition issue. While it is possible the timing slipped, I would not think that would be the most likely scenario based on your limited description of running well for 10 minutes. it is possible the ignition system got wet and was only firing randomly - WD40 can fix this real quick or just wait to dry out.

Usually, a backfire caused by fuel is from an overly rich mixture, but it can also be caused by a lean mixture. Fuel can get so lean it does not ignite (starts to run rough as you stated) then after a few rotations the unburned lean mixture richens up in the exhaust and kaboom. How cold was it outside? It is possible water in the gas started freezing and making the fuel mixture way too lean. If this is the case, the tractor will start and run fine in warmer temps. Another scenario is crud getting into the carb and partially blocking the main jet also making it too lean. if this is the case, it will continue to run rough or not at all until the crud is cleaned out. IMO - I would first check the fuel first as that would be the most likely scenario based on your description.

Good luck,
Dan