Ford 2n alternately backfires then run fine in neutral

[John Kramer]

My Ford 2n suddenly started losing power under load (shredding) and then when put in neutral and switching off the pto, it resumes running at full speed. Put it in gear and it moved on but soon lost power again. This time it was not under load. Cleaned the carb, replaced the fuel shutoff valve, filters and bowl, cleaned out area around governor, replaced ignition coil, new spark plugs, complete tuneup including replacing points. Now when I start it and it starts real easy, it backfires for several minutes and then levels out and surges to full speed for awhile then repeats. Can't even put in gear because it loses all power. Have reset the air intake needle on carb to full rich - all the way in. Fuel needle is out 2 full turns. Adjusting either one seems to have no effect on operation. Anyone have any suggestions?

 

[California]

Here's one of the least likely - but most difficult to diagnose - things that can happen on a gas engine.

Assuming that Ford has some kind of ignition advance, the breaker plate rotates a little. And there's a wire from the points on that plate, to an exterior connector where the coil wire is attached.

I bought an old car where that wire rubbed and grounded intermittently. It could cause rough running, no start, or even occasionally firing a cylinder when it wasn't supposed to which bucked. As I recall I had to remove the breaker plate before I could even see that wire and what it rubbed against.

Your problem is likely something else but I would check for this, just in case.

 

[RickB]

Failing ignition switch, failing ballast resistor and/or high resistance in the wiring harness ignition circuit.

 

[John Kramer]

Thanks. Rebuilt carb...now constant backfire but it starts easy and keeps running. Also changed out the ignition coil. Hate to think about rewiring. Any other suggestions before I go to that extreme?

 

[super55]

Just out of curiosity did you hook a timing light back up to check the advance on the timing when you popped the cap off. It almost sounds as if the timing is off.

I'm not sure if this is it or not but it my Oliver a few years ago was losing power under load and such. My culprit was a piece of linkage had developed a flat spot and was causing the governor not to operate smoothly and was hanging up. Ended up having to drill a larger hole and weld on a thicker bolt for a stud. Might want to try disconnecting the governor linkage and running it and make sure that is not causing it to idle all over the place.

 

[RickB]

Thanks. Rebuilt carb...now constant backfire but it starts easy and keeps running. Also changed out the ignition coil. Hate to think about rewiring. Any other suggestions before I go to that extreme?

Rewiring a 2N is hardly an extremely difficult project, if necessary. I never heard anyone say they should not have replaced 70 year old wiring when all is said and done.

 

[TomNOh]

Rewiring a 2N is easy-peasy. No big deal at all. Hopefully you cleaned out the screen on the inside end of the fuel inlet elbow on the carburetor when you rebuilt it. Also, it's easy to set your ignition points gap to .015" if you remove the 2 distributor mounting bolts & take it to the workbench. Do yourself a favor & buy yourself an I&T FO4 service manual at Tractor Supply. It will tell you in detail how to do all of this.

 

[John Kramer]

Rewiring a 2N is hardly an extremely difficult project, if necessary. I never heard anyone say they should not have replaced 70 year old wiring when all is said and done.

Rewired two years ago. Found problem in distributor/coil connection, so tractor starts and now runs smoothly for a bit then starts backfiring

 

[California]

Did you look at the wire inside the distributor that goes from the points to the external connector?

 

[Jerry/MT]

Have you checked the advance mechanism for sticking? It has a front mount distributor so you can set the initial timing after removing the distributor. Then make sure the advance mechanism is not sticking.