Quick "stupid" question about spark plugs

Discussion in 'Mechanic and Repair' started by updara, Oct 27, 2013.

  1. updara

    updara LawnSite Member
    Posts: 43

    alight, i have a quick, yet may come off as stupid to some, question. But is their any danger of running spark plugs to long? I know after awhile, and lots of use, the gap can widen and become larger, yada yada yada, but is their any danger in running one to long if you just re-gap it? the ngk spark plug in my lawn mower had been in there for 5 years, and i've never taken it out to check the gap. My question is, will running it to long without taking it out and checking the gap hurt anything, if it's still running good? it's running fine, so i don't see a need to pull it out, but will any "odd" thing happen, like say when a spark plug gets old, it loses it's "power" and doesn't fire good enough and stuff like, say carbon, can build up because the plug is old? If you do take one out and re-gap it, and put it back in, will anything bad become of the equipment because the plug is old?

    I know some people change their plugs every year or two years, but i can't see a reason for it, other than they just want a new one? If it's running good, why would they take it out and change it? to me it's just a waste of time, wear and tear on the spark plug threads, and waste of money, but is there a reason they do it?
     
  2. dutch1

    dutch1 LawnSite Silver Member
    from Jayhawk
    Posts: 2,231

    I have no idea what engine you have but if it's a Kaw, check your manual that accompanied the engine--if I remember correctly they recommend replacing the plug every 100 hours--that's the best reason. New plugs, air filter, oil filter, oil, blade sharpening/replacement along with any adjustments, were all part of the Preventative Maintenance package our shop provided. I don't recall the recommendations other manufacturers may have.

    Certainly you can run a plug as long as you'd like but at a buck 99 each, they're about the cheapest maintenance item you can invest in.
     
  3. updara

    updara LawnSite Member
    Posts: 43

    oops! i should have been more specific. it's an old briggs push mower. but i'm also asking for like weedeaters, chainsaws, generators, and such. just all around small engines.
     
  4. Restrorob

    Restrorob LawnSite Fanatic
    Posts: 11,024


    If your too lazy to clean or too cheap to replace the plug run it till it quits, Then you'll have to buy one and replace it.

    Most change them because they do get to a point of not firing correctly or drop spark completely, They'd rather not be down in the middle of a job.....
     
  5. updara

    updara LawnSite Member
    Posts: 43


    when you say "you'll have to buy one to replace it" are you talking about new plug or new equipment


    I always carry around extra plugs with me in the vehicle for back up, so i'm not that worried about getting knocked out in the middle of a job
     
  6. Restrorob

    Restrorob LawnSite Fanatic
    Posts: 11,024

    ......................... ;)
     
  7. updara

    updara LawnSite Member
    Posts: 43



    oops, my bad! :hammerhead:
     
  8. exmarkking

    exmarkking LawnSite Bronze Member
    Posts: 1,012

    I don't see anything terribly wrong by not replacing it. Now as the plug gets hours on it, you could notice more fuel consumption do to the plug not burning the fuel completely but then you would also notice a drop in power, starting etc. possibly the plug threads could seize in the motor which would be a problem to deal with. I think it's really more of a preventative maintenance thing like said above.
    Posted via Mobile Device
     
  9. updara

    updara LawnSite Member
    Posts: 43

    I can agree with that, because i don't use, and will not use anti seize on spark plug threads. on NGk's website it says the coating used on the threads of their plug resist corrosion and will act as a release agent when you take it out. i seen else where that this only works once, so if you take it out, then put it back in, it loses it's "releasing" power. So i guess that would then be a good reason to replace it with just a new one. I pulled the champion outta my chainsaw just a bit ago, because i don't like champion plugs, and put a denso in, and it runs better, so i may/ may not just go ahead and replace them once a year, as others say is a good preventative measure. after all, ben franklin did say an ounce of prevention beats a pound of cure! I was just worried about stripping the threads outta the head. it would be ashamed to ruin a 400 dollar weedeater just by changing a 3 dollar spark plug! lol
     
  10. updara

    updara LawnSite Member
    Posts: 43

    On the topic of spark plug threads, has any one here ever stripped the threads and fixed the problem without buying a new head? i got the idea once to use JB weld. lol


    I may have to change the plugs in my RX-7 soon, and i'm paranoid of stripping the threads in it, because it would be a MAJOR PITA to find another rotor housing and having to strip down the engine! :realmad:
     

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