Engine Was Talking - Spark Plugs

[Mr_Joe]

Yes, the Kohler engine on my 8 Y/O Cub Cadet was talking the other day, slow to start then rough & some smoke on start up. I changed the plugs not to long ago, the most 3 years, maybe just 2.

I had the standard Champions in, common size, but don't have it here. The mid level quality was out of stock at the store, so I decided to go with the $8.20 Denso Iridium plugs that cross reference. I didn't want to go with the $2.15 Champions this time.

I just stopped by to report it was a night & day difference. Easy start up & running smooth as a baby's bottom. Just a reminder, don't try to reset the gap on an iridium plug.

 

[GreeCguy]

Originally Posted By: Mr_Joe
Just a reminder, don't try to reset the gap on an iridium plug.


What will happen if you try to reset the gap on an iridium plug?

 

[Tegger]

Originally Posted By: Mr_Joe
don't try to reset the gap on an iridium plug.

There is absolutely nothing wrong with resetting the gaps on an iridium plug. NGK, just as a for-instance, even has a maximum range up-and-down to which the gap may be adjusted.

 

[RF Overlord]

Denso Iridiums used to be a fad popular with the Mercury Marauder crowd. After a time it was realised that they really don't do much that basic, and way less expensive, Motorcraft Platinum plugs won't do.

The reason they say "not" to adjust the gap is that unless done carefully it's easy to damage the fine-wire tip of the centre electrode...no using those "coin" gappers, for instance.

 

[Tegger]

Originally Posted By: RF Overlord
The reason they say "not" to adjust the gap is that unless done carefully it's easy to damage the fine-wire tip of the centre electrode...no using those "coin" gappers, for instance.

Correct gapping technique does not involve any sort of pressure against the live surfaces or edges of the electrodes.

Here's a YouTube video from NGK that shows how to do it:
http://www.youtube.com/watch?v=lk70oyUEftY

 

[SHOZ]

From the factory my Denso Irdiums come gapped at .028" But the OEM spec is .038-.040"

 

[Tegger]

Originally Posted By: SHOZ
From the factory my Denso Irdiums come gapped at .028" But the OEM spec is .038-.040"

Then you bought the wrong ones.

Find the right part, with Denso's help:
http://www.densoiridium.com/find_part.php?tab=1

 

[Mr_Joe]

That is a helpful gapping video. I had heard not to mess with an iridium plug gap. I guess if you're careful you could adjust as needed.

 

[Errtt]

I've adjusted iridium plug gaps via the ground electrode with no adverse issues. My understanding is not to mess/pressure against the center electrode. On most, I didn't have to mess with the gap though.

 

[fdcg27]

How many hours did these Champs have on them?
I've found Champs to be the go-to plug on my OPEs, although I haven't tried the uber expensive NGKs you're using.
Any new plug will bring easier starting.
The key is how long that easy starting lasts.

 

[Mr_Joe]

The Champions I took out were 2-3 yrs old. I didn't write down when I changed them last. One plug was very wet when I took it out, don't think it was firing very well cold.

The hard starting just came on recently. The mower is used a good bit, 5 acre property, though not all of it mowed. I usually change plugs when things are suspect, or after a handful of years. I normally don't drop in a new plug every year, somewhat dependent on the machine.

 

[fdcg27]

Agreed there.
No reason to pull a plug if the thing starts okay and runs well.
On five acres in an area that probably sees a decent amount of rain, you're probably putting some real hours on the machine in a few years.
I'd be interested in hearing how these NGKs work out.
Costly, but they should be very durable.

 

[Mamala Bay]

Have a manufacture defective Kholer small engine(splash lubrication) that heats up more than normal. Problem wasn't known until after the 1 year warranty so got stuck with it.

Engine came with a Champion plug. What I notice was the Champion plugs didn't last as normal, rather a short life. After so many few hours, very hard starting very fustrating starting.

Gave up on the Champion and wanted to see how well the NGK would do...clearly an engine problem so I thought would the spark plug make a difference.

The NGK was like night and day. Started with 1-2 pulls after so many hours just like the Champion when new, very strong starts.

What I think happened was the Champion plugs degraded from heat or didn 't have a consistant heat range versus the NGK. Echo did test the newer 2 cycle engines(Shindaiwa) because they run hotter versus the old and if a plug goes off it's heat range it can shorten the life of the motor 25-40% in these newer hotter 2 cycle engines. Echo does recommend the NGK or the equivilent Denso. After hearing of this test I wanted to see if the NGK were as they say.

I'm a believer, I went through so many Champion plugs on a defective motor but that may not be the fault of Champion...But with the NGK it's been like night and day.

 

[Audioquest]

I completely transformed my Tecumseh powered snowblower from switching out the Champion RJ19LM spark plug for a NGK BR2LM. Even with electric start, I'd eventually have to resort to quick-start spray to get it to fire. Now with the NGK, I use the manual pull start and it fires on the first pull every time. NGK ftw!