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Subject: New Plugs Running Rough

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Rick Gowdy    Posted 07-26-2017 at 15:45:26 [URL] [DELETE]        [Reply] [Email]  
  • New Plugs Running Rough
  • Finally did some long overdue work on my 52 8N: new exhaust manifold gasket, new trans. fluid, cleaned oil breather cap, new oil in air filter cup, flushed radiator,
    new plugs, cap and rotor. Ran fine day one picking up stuff w/carry-all. Day two
    started fine, but when I engaged the rotary mower it became very rough/weak. Double-
    checked plug wires and think I have it right. Thoughts? Thanks.

    SelectOSpeed    Posted 07-27-2017 at 08:34:33 [URL] [DELETE]        [Reply] [Email]  
  • Re: New Plugs Running Rough
  • Don't forget to put some lube on the distributor cam. Without it the rubbing block on the points will wear away very fast and wreak havoc with ignition timing and engine performance. SoS

    Rick Gowdy    Posted 07-27-2017 at 08:50:03 [URL] [DELETE]        [Reply] [Email]  
  • Re: New Plugs Running Rough
  • Thanks. What do you recommend?

    SelectOSpeed    Posted 07-27-2017 at 18:38:38 [URL] [DELETE]        [Reply] [Email]  
  • Re: New Plugs Running Rough
  • I've used Niehoff NL-2 over 40 years. SoS

    steveVa    Posted 07-26-2017 at 16:29:49 [URL] [DELETE]        [Reply] [No Email]  
  • Re: New Plugs Running Rough
  • Points?? Sometimes new points need to be re-gapped in a short time once they rub in off the high spot. Especially cheap points. Also, did you gap the plugs when you put them in??

    Rick Gowdy    Posted 07-26-2017 at 16:46:49 [URL] [DELETE]        [Reply] [Email]  
  • Re: New Plugs Running Rough
  • Did not replace points. Did not gap plugs. Also, they are unused Champion H12, but approx. 15 years old if that makes a difference.

    steveVa    Posted 07-26-2017 at 18:14:28 [URL] [DELETE]        [Reply] [No Email]  
  • Re: New Plugs Running Rough
  • Point gap could be too wide if you filed them and did not gap them. Breaking up at high rpm is a sign of gap too wide. I would also look at the plugs and see how they look after a short time of running. That will also give you a chance to check their gap.

    Rick Gowdy    Posted 07-26-2017 at 19:11:00 [URL] [DELETE]        [Reply] [Email]  
  • Re: New Plugs Running Rough
  • The points had NO gap. Must have loosened when I cleaned them. Reset and she runs like a dream. Just did a little bush hogging and she did great. Thanks so much. You all are a great resource for the novice. Best, Rick

    steveVa    Posted 07-27-2017 at 11:06:00 [URL] [DELETE]        [Reply] [No Email]  
  • Re: New Plugs Running Rough
  • Glad you figured it out. I usually try the easiest things first and points on a side mount dist. are pretty easy to check.

    Bruce (VA)    Posted 07-26-2017 at 16:03:14 [URL] [DELETE]        [Reply] [Email]  
  • Re: New Plugs Running Rough
  • Check the firing order again, 1-2-4-3, CCW.

    Did you set the plug gap at .025?

    Points at .025?

    Did you set the timing now that you have a new set of points?

    Rick Gowdy    Posted 07-26-2017 at 16:16:13 [URL] [DELETE]        [Reply] [Email]  
  • Re: New Plugs Running Rough
  • Will check order again. Did not set plug gap. Just put in as they came from the box. Will check points gap, but did not replace points just cleaned them up a little. Does any of this explain why it runs fine until under load? Thanks.

    Bruce (VA)    Posted 07-27-2017 at 08:15:11 [URL] [DELETE]        [Reply] [Email]  
  • Re: New Plugs Running Rough
  • " Just put in as they came from the box."

    You need to set the gap.

    Rick Gowdy    Posted 07-27-2017 at 08:53:07 [URL] [DELETE]        [Reply] [Email]  
  • Re: New Plugs Running Rough
  • Did that as well. They were pretty close, but I closed two of four that were a little wide. Thanks again.

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