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Subject: What to do with 8N?

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Del Huebner    Posted 02-19-2017 at 10:14:51 [URL] [DELETE]        [Reply] [No Email]  
  • What to do with 8N?
  • Recently acquired 48 8N looked like it was going to be OK. It hadn't run in 5 years but after adding ATF to the cylinders and doing some rewiring it fired right up. Everything looked good with 40# oil pressure. After running it a while it started to smoke on acceleration. Son-in-law found the problem, when he pulled #4 cylinder plug wire it stopped smoking so we know where the problem is. My question, is it possible to just pull one piston and do what needs to be done, maybe rings, maybe more. I am a parts replacer not a mechanic so would probably have to hire this done if it is even possible. The other option is to use it for a donor tractor.

    John in Mich    Posted 02-20-2017 at 09:34:18 [URL] [DELETE]        [Reply] [No Email]  
  • Re: What to do with 8N?

  • With those compression readings, I would NOT open up the engine. Pull all four spark plugs. Add some more ATF or MMO and let it set a few days. Turn it over by hand or tap starter button for small rotation. Add more ATF or MMO and soak a day or two.
    Take new readings (for grins).
    Once you start it again, try to lean carb (big screw). I've had bad smoke after loosening up rings and it was the carb too rich. JMHO

    Rustyal    Posted 02-20-2017 at 07:06:40 [URL] [DELETE]        [Reply] [No Email]  
  • Re: What to do with 8N?
  • I've got one that is really bad and getting worse. But it just keeps smoking along and working hard. An ice sheet is about to break off Antarctica cause an 8n is smoking. I would replace the rings in all four cylinders.

    Bruce(OR)    Posted 02-19-2017 at 13:20:14 [URL] [DELETE]        [Reply] [No Email]  
  • Re: What to do with 8N?
  • Stewart-Warner CD-2 oil detergent, or GM's Engine Oil supplement.
    If it was me and I figured the possibility of stuck rings I would be looking at "snake oil" just before an engine rebuild. I know both of those work very nicely to free up noisy lifters. Both of those additives work well with a fresh oil change. Might even work to free up stuck rings, if that is what you have. The batteries in my crystal ball have gone dead, so it doesn't work too well anymore. How's your's working?

    Bruce(OR)    Posted 02-19-2017 at 17:55:42 [URL] [DELETE]        [Reply] [No Email]  
  • Re: What to do with 8N?
  • Duh. . . .That's whut I forgot. You can either go with a hotter range spark plug if it is fouling out or a spark plug non-fouler. That non-fouler is basically a spark plug extension that screws onto the bottom of the plug before you screw it into the engine. It encapsulates the electrode and slows down, if not eliminating, the oil fouling tendencies of a bad cylinder. There is also the train of thought that says as your raising the base of the spark plug from the head and this also acts to raise the plug operating base temperature range.

    Del Huebner    Posted 02-19-2017 at 11:05:59 [URL] [DELETE]        [Reply] [No Email]  
  • Re: What to do with 8N?
  • Thank You everyone. Here are the compression readings I just took.
    From 1 thru 4 dry--90-95-70-80
    From 1 thru 4 wet--100-120-110-110

    steveVa    Posted 02-19-2017 at 17:12:57 [URL] [DELETE]        [Reply] [No Email]  
  • Re: What to do with 8N?
  • All the more reason to add some MMO and run it a bit. Nothing to loose. Those rings might free up some more. Worse case I see for now is if it doesent clear up you pull the head and chech head gasket between 3 and 4. Many a tractor smoke on accelleration. I WOULD RUN IT TILL IT FOWLES A PLUG. If it ever does...

    kylemorley    Posted 02-20-2017 at 11:16:08 [URL] [DELETE]        [Reply] [Email]  
  • Re: What to do with 8N?
  • I agree, MMO or ATF and time. Every minute you can keep it running (or even better, working) increases the odds you may get away without major surgery. You might want to put some MMO in the engine oil too, and an anti-fouler on the bad hole.

    A ring soak isn't magic and won't work on all machines, but when it does work, it is downright miraculous. My 8n went from an oil guzzling, smoker that needed the plugs washed in gasoline each time I started it, to a good running easy starting machine that burns almost no oil.

    R Geiger    Posted 02-19-2017 at 10:35:51 [URL] [DELETE]        [Reply] [No Email]  
  • Re: What to do with 8N?
  • If you open it up to do anything, mission creep will set in, I would keep adding ATF to that cylinder and keep running it. If it only smoking when you accelerate it, I would run it as is, it may last for years with a clean plug in that hole from time to time.

    SteveVa    Posted 02-19-2017 at 10:32:08 [URL] [DELETE]        [Reply] [No Email]  
  • Re: What to do with 8N?
  • I would check compression and run it a bit before tearing it down.

    Lenny    Posted 02-27-2017 at 19:13:54 [URL] [DELETE]        [Reply] [Email]  
  • Re: What to do with 8N?
  • Ditto.
    My 47 2n was a bad smoker when I first brought it back to life.

    I went and found a steep hill to lug it up several times and really make it work for a living for an hour or so. It quit smoking.

    The older rings were known for losing their "seat" when set for a long time or not warmed up to operating temperature often.

    "run it like you borrowed it from your ex wife!"

    AL CT    Posted 02-19-2017 at 10:25:47 [URL] [DELETE]        [Reply] [No Email]  
  • Re: What to do with 8N?
  • I'll offer my humble opinion. If you're thinking of doing one cylinder, waste of time. Do it correctly and do a complete overall once it's exposed. Price of the complete kit plus self labor (easy to do) makes for one very inexpensive overall. The worst part is removing the sleeves, maybe there's someone close by who you can rent or borrow the removal tool. Invest in an engine stand, makes the overall so much easier.

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