126M02-6675-F2 Won't Run - Replaced Carb & Flywheel Key - Still No Go

[ILENGINE]

Unless specified by the customer they get NGK's because they are 50¢ cheaper & I charge the same price for all plugs.
NGK's also come in 10 packs & Champions or Bosch come in 4 packs or 10 x 4 packs
Same grades as Illengine unless there are signs of the engine needing a hotter plug.
OTOH
No 1 rule in engineering " if it ain't broke, don't fix it "
As such I would be lucky to change more than 20 plugs a year out of 300 or so jobs
I expect 50,000 to 100,000 miles out of my car plugs
I have plugs in engines that have not been changed since they were made and some of them are near 100 years old from the days of 2 piece plugs .

My truck plugs burn out and start causing issues around 40,000 miles. Oh guess what they are OEM Champion plugs. Because they are an OEM only available through the dealer plug.

 

[StarTech]

Yes plugs can spark outside the compression zone but under compression fail to fire. I had one air compressor years ago that would run fine and build up pressure. It just wouldn't restart if the air was full and it turn out to a bad plug. It had me nearly pulling out my hair as to the cause.

 

[StarTech]

Bert, Most of the NGKs I buy here comes 4 packs. Now some do come in 10 packs but they are usually the 2 cycle plugs.

And IL I have a lot failures of the 10mm CMR series NGK plugs which I am replacing with Bosch plugs but in the long run most plugs are fairly reliable.

Even new plugs can fail straight out of the box.

 

[SamB]

Unless specified by the customer they get NGK's because they are 50¢ cheaper & I charge the same price for all plugs.
NGK's also come in 10 packs & Champions or Bosch come in 4 packs or 10 x 4 packs
Same grades as Illengine unless there are signs of the engine needing a hotter plug.
OTOH
No 1 rule in engineering " if it ain't broke, don't fix it "
As such I would be lucky to change more than 20 plugs a year out of 300 or so jobs
I expect 50,000 to 100,000 miles out of my car plugs
I have plugs in engines that have not been changed since they were made and some of them are near 100 years old from the days of 2 piece plugs .

I don't just change my mower plugs out of boredom. Like you,bert,if it ain't misfiring or hard to start,I leave the plug alone!