Standard spark plugs vs. iridium.........

[7394]

I have the same model Liberty, & since my former Toro had the same Kawasaki engine & I was stocked up. I will be using the OE NGK plugs, till my supply runs out.

 

[Scrubcadet10]

I believe there was an old ford that would spit the plugs out when it was time to change them.

 

[Newokie1959]

I have a Scag Liberty 48" with the Kawasaki FR651V. All is well in terms how it runs, but at some point will change the spark plugs. Do the iridium plugs have enough benefits to justify the higher cost?

Here's how I see this. The OEM (Kawasaki) designed, built, tested and THEN produced and sold that engine. They know what works best. Go with that.

 

[SamB]

No
But I fear we will end up with another synthetic vs plain oil or detergent vs non detergent oil type debate .
Every one who does not have the background knowledge to understand the what & whys will come in ardently throwing hundreds of you tube videos from equally ignorant ego maniacs as if that is somehow proof of some sort , along the lines of east poo cause 5,000,000,000 can not all be wrong.
On some CAR engines the computer controllers need to get clean reliable signals and in that case the exotic metal plugs might be needed.
Mower engines are the cheapest engines that it is possible to make
They run relatively low compression,
They run fixed timing now everyone has given up on electronic variable timing
They run at a fixed speed
And the speed is very low.

Having said all of that, if your mower engine is worn out to the point it gobbles up a pint of oil every time you mow then the exotic plugs will still work long after standard plugs have given up the ghost .

Think about it.
A modern 500cc motorcycle engine is pumping out anything from 50 to 100 Hp with red lines around the 10,000 rpm mark and most of them a fine with standard plugs
A modern 500 Cc mower engine is hard put to pump out 20Hp.

But if it makes you feel better than the man next door then go ahead, the parts retailers need your money .

I put Motorcraft iridium plugs in my Ford Ranger 4.0 because they are so difficult to get to change. I don't want to do it any more often than I need to.
My mowers are super easy to get to the plugs. A buck and a half OEM replacement plug works just as well as a $6.00 plug.

 

[Briantii]

I'd say iridium are for sure "better" technically and they will last longer assuming you have no negative factors affecting the plugs like overheating or fouling. With that said - will you EVER realize any real benefits to justify the costs? Probably not.

Our airplane has a 5.9 liter 6 cylinder air cooled engine making 200hp turning 2700 rpm with dual spark plugs and dual independent magneto fixed timing ignition. Fairly similar to a mower engine in hp per liter and RPM. We run iridium plugs in it because of significantly longer plug life, slightly better low idle smoothness (maybe), easier starting (maybe), and reduced maintenance because the electrodes for them are smaller and re-gapping isn't required. Regular copper plugs last ~400 hours in an aircraft engine, and iridium plugs (also known as "fine wires") can last up to 2000 hours. It's worth it on the aircraft despite some absolutely eye watering prices.

I wouldn't bother on a lawn mower engine though despite the technology being superior. It just doesn't practically make a big enough difference and swapping a plug on a mower every 250 - 500 hours and takes all of 2 minutes and will probably never save you money or hassle.

Yes it's better, no you probably don't need or want it.

 

[upupandaway]

Electricity arcs easier from sharp edges. They say Iridium tip plug is harder than copper plug so it hold the sharp edge longer.
I think plugs are like oil. My car had 150K when i looked inside the cylinder. The hatch marks are still there. I use dino oil. Maybe synthetic is better for extremes that my car never reaches so it lubes the same. I'm sure my replacing my plugs is the same as my oil experience.

 

[matt man]

My spark plugs suck, Why do they put resistor plugs on mowers? I'v had 6 mowers with bad plugs this month. Mostly NGK r

 

[Hal12]

Bought the snapper in 91 I think. Still runs great...never changed the plugs. Maybe I should..

 

[matt man]

Bought the snapper in 91 I think. Still runs great...never changed the plugs. Maybe I should..

Don't do It, Bad omen

 

[Briantii]

My spark plugs suck, Why do they put resistor plugs on mowers? I'v had 6 mowers with bad plugs this month. Mostly NGK r

Wow that's surprising. I wonder if someone got a batch of the fake NGK's from Amazon / eBay.