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Ford 9n

2792 Views 15 Replies 5 Participants Last post by  JohnW
I think I first posted this in the wrong part, trying again. Its been a while since I have posted, my problem is on my 9n. Carb is rebuilt, new plugs wires, points ect all done. It does smoke a little, but my problem is now it smokes a lot and the exhaust smells like fuel. I have tried adjusting the carb and nothing seems to help. Im not sure what to do, if I need a new carb or is it something I can fix. Any help would be great.
Thank You
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I could be that one cylinder just isn't getting a good spark and isn't actually firing, which would result in all of the fuel going into that cylinder coming out the exhaust unburnt. I would test the spark on all 4 cylinders, plus make sure that you installed the new plug wires in the proper order.
Checked all the plugs they have spark, they have like black soot they were new yesterday. When I did the wires I did one at a time. It started before I changed them. I took the carb apart and re ajusted it still doing it. It still smells like to much fuel. My neighbor said it might be the rings, would that cause that. At a idle seems to be ok when I go full it gets worse.
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You should really get a compression test on all 4 cylinders. I believe that you should be somewhere above the 100 psi mark, though it is more important that all the cylinders read close to the same than to any real number. If you find one or two cylinders 20 pounds below the others, then squirt a few shots of oil into the cylinders and test it again. If the readings jump significantly, it is due to ring trouble.

Worn piston rings generally cause blue smoke out of the exhaust, not black. So I doubt this is your issue, however, test to be sure. More likely than rings or carb trouble is worn points, condenser, cap and rotor. Clean, or replace, and adjust the ignition before replacing the carb. Also, try unhooking your air cleaner from the carb and see if this helps, and make sure that the choke is in the open position. I just had a friend of mine bring me his tractor to look at, for running rough and fouling plugs, and the only thing wrong with it was that he had the choke pulled out and didn't realize it. Sounds stupid, but it happens to the best of us.
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I have to think it is something simple and since you say you rebuilt the carb my money is on the choke plate being installed wrong and not opening. I say this because a few years age someone else on this board had done that when rebuilding their carb.
I personally did not rebuild the carb I had someone do it for me, I will try to get a picture of the choke plate this weekend. I should of been more exact of the smoke, it did smoke a little blue before, the smoke is a thick blue now that smells like gas. Did try running it with the air cleaner off. I replaced point cap and ect. I am not sure how to adjust the ignition, I never did it before this is the first tractor I have owned so I am learning as I go. I also tried it with choke unhooked it still was doing it. I also did change it over to 12v last weekend.
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If it is a thick BLUE smoke then you are burning oil it would be black if it were running to rich so the fuel system is not your problem. You need to do a compression test.
I did check the spark again it is verry little, but is sparking but not much. Is there a way to adjust it to spark more, maybe less gap?
What number of spark plug are you using??
What do you mean very little? Spark is judged by color, blue good, yellow bad. Proper gap of the points and spark plugs is the only adjustment to get good spark.
I'm using autolite 437. It is a faint blue.
Do a compression test and go from there. The spark should be blue and SNAPPY, the Autolite 437 is the correct plug to be using.
I bought a compression tester. A cheap one from autozone. I started in the front of the motor ans went back 1st was about 110, 2nd was 95, 3rd 120 and 4th was 125
Looks like your problem is on #2 now you need to do it again this time add oil to the cylinder before you check it and see if the compression comes up on it. The other 3 are right in the ball park for real good compression on these old engines.

Right now I am beginning to think you may have broken rings on #2 for it to be smoking heavy blue smoke like you say it is.
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When I did that test the motor was cold, and wouldn't start. Charged the battery ran it till warm, and all were around 90-95. When I was putting the plugs back in I dropped one of the small rings that come with the spark plugs in the stone. I reinstalled the plugs with out the rings on the plugs and that cut the smoke at least by 25%. It still smokes but not as much. I think a rebuild is in the future this winter.
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I would say you are correct, blue smoke is oil burning and the only way to correct that is to R&R the cylinders and rings. You might try running a heavier weight of oil to maybe slow it down a bit.
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