[NA] riding lawn mower spark plugs

WannFly

WannFly

Final Approach
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Priyo
Worth digging into it to see if it's within specs?? 5 buck each, need 2... just throw the old ones and get on with life??

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Check the gap on the old ones, look for wear, throw them away after you get new ones.....

What brand lawn mower?

I live in the desert, what is a lawn mower and what is it used for....? :lol::lol::lol:
 
Spend the 10$ and move on to something else.
 
Zeldman said:
Check the gap on the old ones, look for wear, throw them away after you get new ones.....

What brand lawn mower?

I live in the desert, what is a lawn mower and what is it used for....?
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already have new ones...wondwring worth the time to do the checking... it's a JD 125. Just took the snow blower attachment off (Yes, that's a thing)

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Never hurts to check the plugs to see what the engine is doing.

We had a little snow fall last week, but it just turned into mud when it hit the ground. I really hope we are through with snow for now.
 
Before you waste $5.00 on spark plugs you might not need, I would buy one of these so you can clean and test first.
 
Zeldman said:
Never hurts to check the plugs to see what the engine is doing.

We had a little snow fall last week, but it just turned into mud when it hit the ground. I really hope we are through with snow for now.
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Exact same tolerance and spec. Not flying today.... guess u guys already figured that out
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Ok someone explain this to me. I took out 2 spark plugs and the gap is exactly .76 in both which are in the book. Both the new ones, same model number are. 80 .... So as the spark plug is sparking away to glory, does that gap diminishes??? What exactly happens?

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Gap gets very slightly bigger as the electrode erodes - probably not enough to measure after just a couple years in a lawn mower. Someone probably set the gap smaller when they were first installed
 
$5? I think mine was only $3 at the local discount auto parts store. Yeah, I just chuck the old one.
 
Capt. Geoffrey Thorpe said:
Gap gets very slightly bigger as the electrode erodes - probably not enough to measure after just a couple years in a lawn mower. Someone probably set the gap smaller when they were first installed
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But then why the heck are the new ones bigger than spec?

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flyingron said:
$5? I think mine was only $3 at the local discount auto parts store. Yeah, I just chuck the old one.
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Your must be experimental

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Spark plugs are built to size / heat range specs. The plug gap is application specific. Your engine may spec .76 inches and another engine that uses the same plug could be different - .65, .8, whatever.
 
A whole day on the damn tractor... am ready for some good single malt

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If the mower runs fine I'd just throw some seafoam in the gas tank, change the oil, check the air filter and go. If you really want to do plugs or it doesn't run right I'd just replace them. These small engines don't exactly have precise tolerances and most of the time when they don't run right it's because of dirty carburetors that sat during the off season and got full of deposits from old gasoline.
 
cowman said:
If the mower runs fine I'd just throw some seafoam in the gas tank, change the oil, check the air filter and go. If you really want to do plugs or it doesn't run right I'd just replace them. These small engines don't exactly have precise tolerances and most of the time when they don't run right it's because of dirty carburetors that sat during the off season and got full of deposits from old gasoline.
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Yep. Most problems can be avoided simply by purging the fuel before storage for the off-season. I add whatever fuel system cleaner I have handy to what's left of the fuel, run it to empty, change the oil, change the air filter if it has one, and that's that.

I always have spare plugs handy, but they only get changed as needed. The one in the snow blower is three years old and still works fine. The one in the lawn mower usually needs to be changed every year. I have more grass than driveway. It's also a much older engine, and they do tend to burn more oil as they get older. I probably should overhaul it one of these days.

Rich

EDIT: If the gasoline was fresh the last time it was filled, then you can probably get away with adding some STA-BIL to the tank, starting it up, shutting off the fuel valve, and running it until what's in the carb is used up. I've never had a problem doing it that way. It's not what most experts recommend, though.
 
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Clark1961 said:
I see what is wrong...they have "champion" on them.
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How true. When I was racing motocross in the 90's, my Honda CR125's and CR250's came with Champion plugs from the factory. On initial startup for my break-in ride, they would run for a couple minutes, foul the plug, and I'd put in the correct NGK plug and live happily ever after. After two bikes like that I started putting in the NGK during my new bike prep and never had an issue.
 
Man, you guys must have really volatile gasoline in your area of the country. I change out the spark plug on my 15HP B&S rider once every 3-4 years and don't look at them in between services. Change the oil/filters once a year and go on. Zero-ethanol fuel only and I put it to bed in October with a full tank. Fires up each March without a hiccup. '93 model, too, lol.

Of course she ain't pretty, and I couldn't sell it for more than $250 on Craigslist if I wanted to, but she just won't die! I'm sure if I had a $5K zero-turn I'd probably be doing the full inspection each year on every major component.


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the .76 spark plug gap I'm sure is millimeters. .76 mm is approx. .030 inches. :)
 
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