IS700Z - Iridium plugs FYI

[slomo]

As noted lets hear back after 5 more hours. Bet those NGK's will hit some glass soon. I agree there is an overly rich condition going on. Or you had a Chinese copy of a Champion that you threw away.

Just picked up a 1993 McLane edger with a 3.5hp Briggs. It has a Champion J19LM plug. Carb was all jacked up, choke stuck on. Linkages all messed up. Plug was totally black with a solid carbon gap. Cleaned the plug down to metal with a hand wire brush. Fired up on the first pull. Plug looked original as in 1993. All rusted on the hex head and boot end. Summation, plugs rarely go bad. Normally when they do it's from poor fuel ratios slash carbon fouling. Not a plug issue but a carb or plugged air filter issue.

slomo

 

[Hammermechanicman]

More rambling from some random guy on the internet.

Small air cooled engines unlike automotive engines do not have a thermostaticaly controlled cooling system. Engineers need to design them to operate at full power over a wide temperature range under varying load conditions. This means there are a lot of compromises with their design and the engines will operate at different temperatures depending on ambient temperature and load.
We also need to understand how a sparkplug works. For a sparkplug to operate properly it needs to have the temperature of the center electrode in the self cleaning range which is approximately 500*C to 850*C. What this means is anytime a plug is operating below 500*C it is carbon fouling regardless of type or brand. So when any piece of equipment is started the plug is carbon fouling until the the sparkplug reaches the self cleaning range and then operates there till all the carbon is burned off. This is why we have different heat range plugs to try and match the plug to the operating temp of the engine. Many people look at a plug that is black with carbon fouling and immediately assume the engine is running rich. This is usuallly not the case. The engine is just operating with the sparkplug below the self cleaning range. Even if the engine is running a lean mixture the sparkplug will carbon foul until the sparkplug reaches the self cleaning range. Many people state all the Briggs L head engines run rich because every sparkplug they have taken out was black and must be running rich when in reality the low compression engines don't generate a lot of heat and unkess the engines are operated at full load they won't get the plug into the self cleaning range. Many people think that not running equipment at full throttle is better and will make it last longer when the opposite is true. Engine will run best at full speed under a load. Overheated is bad along with not enough heat being bad also.

And remember kids to take everthing you read on the internet with a grain of salt.

 

[bertsmobile1]

As noted lets hear back after 5 more hours. Bet those NGK's will hit some glass soon. I agree there is an overly rich condition going on. Or you had a Chinese copy of a Champion that you threw away.

Just picked up a 1993 McLane edger with a 3.5hp Briggs. It has a Champion J19LM plug. Carb was all jacked up, choke stuck on. Linkages all messed up. Plug was totally black with a solid carbon gap. Cleaned the plug down to metal with a hand wire brush. Fired up on the first pull. Plug looked original as in 1993. All rusted on the hex head and boot end. Summation, plugs rarely go bad. Normally when they do it's from poor fuel ratios slash carbon fouling. Not a plug issue but a carb or plugged air filter issue.

slomo

Agree withy your sentiment, but plugs do go bad, and modern plugs do it more often than old plugs.
Because we now have very sensitive chemical test gear we can detect the most minute amount of things like lead in exhausts.
Now as we all know lead was invented by Satan and any one who even looks at as little as single molecule of lead will instantly get cancer, grow 3 heads and have defective children.
Now the problem is the white glaze used on insulator nose contains lead
And a couple of atoms of this lead can be liberated during running and end up in the exhaust gas where it will cause the entire plant to cease to exist ( or so the EPA thinks )
Thus the nose insulators on most plugs are no longer glazed.

This would not be a problem if we were burning real petrol ( a now mythical liquid not seen for several decades & believed to be extinct ) , but we are burning "fuel".
The downside of fuel is it is quite conductive a cylinder pressures and will happily deposit upon the afore mentioned unglazed plug nose where it makes a spark track down from the center electrode to the base ( ground ) of the plug.
THis path can only be burned off and if the plug won't fire that is sort of difficult to do.

Thus you do get a plug that will seem to be "bad ring out of the box".

 

[SirMowzalot]

As noted lets hear back after 5 more hours. Bet those NGK's will hit some glass soon. I agree there is an overly rich condition going on. Or you had a Chinese copy of a Champion that you threw away.

Just picked up a 1993 McLane edger with a 3.5hp Briggs. It has a Champion J19LM plug. Carb was all jacked up, choke stuck on. Linkages all messed up. Plug was totally black with a solid carbon gap. Cleaned the plug down to metal with a hand wire brush. Fired up on the first pull. Plug looked original as in 1993. All rusted on the hex head and boot end. Summation, plugs rarely go bad. Normally when they do it's from poor fuel ratios slash carbon fouling. Not a plug issue but a carb or plugged air filter issue.

slomo

The Champions are in the NGK boxes and sitting in my tool box because I already planned to compare them should the problem return. I also said under 5 hours because I was too lazy to go check the meter. It was more like 2.5-3 at the time of the swap. I have the exact number in a log out in the garage. I've run it 2 more times since the swap and no issues so far. I only ran it 3 times when I decided to address the rough idle. Not to mention plugs aren't the only indicator of an AF issue. There's no fuel smell, and this thing does wheelies on level grade so no acceleration issues. When there's an AF issue there are typically multiple symptoms. That's just not the case here.

But by all means, you folks can keep hoping I experience a problem to validate your own beliefs. I won't, which validates my decision to never allow third parties to touch my engines small, auto, or otherwise. But one thing to note. I knew the engine had Champions the day I brought it home. Because when I brought it home I ordered all the required parts for the next few maintenance intervals. They're in a box in a cabinet standing in my garage. That's just how I operate. I left the Champions in already expecting a problem, but hoping I'd be proven wrong. I gave them a chance. They gave me what I expected. Now I have to order another pair of NGKs for next year.

But hey, since you all make your living on how often a customer brings a machine in for service, keep right on using those Champions, lol. Same goes for oil. You keep right on using the dino-crap, and I'll keep right on using the "unnecessary" Amsoil. I'm about ready to do my first unnecessary oil change as well. Because waiting 25 hours like my dealer said on a brand new engine with dino in it makes about as much sense as waiting to get shot before putting on a vest.

 

[slomo]

The Champions are in the NGK boxes and sitting in my tool box because I already planned to compare them should the problem return. I also said under 5 hours because I was too lazy to go check the meter. It was more like 2.5-3 at the time of the swap. I have the exact number in a log out in the garage. I've run it 2 more times since the swap and no issues so far. I only ran it 3 times when I decided to address the rough idle. Not to mention plugs aren't the only indicator of an AF issue. There's no fuel smell, and this thing does wheelies on level grade so no acceleration issues. When there's an AF issue there are typically multiple symptoms. That's just not the case here.

But by all means, you folks can keep hoping I experience a problem to validate your own beliefs. I won't, which validates my decision to never allow third parties to touch my engines small, auto, or otherwise. But one thing to note. I knew the engine had Champions the day I brought it home. Because when I brought it home I ordered all the required parts for the next few maintenance intervals. They're in a box in a cabinet standing in my garage. That's just how I operate. I left the Champions in already expecting a problem, but hoping I'd be proven wrong. I gave them a chance. They gave me what I expected. Now I have to order another pair of NGKs for next year.

But hey, since you all make your living on how often a customer brings a machine in for service, keep right on using those Champions, lol. Same goes for oil. You keep right on using the dino-crap, and I'll keep right on using the "unnecessary" Amsoil. I'm about ready to do my first unnecessary oil change as well. Because waiting 25 hours like my dealer said on a brand new engine with dino in it makes about as much sense as waiting to get shot before putting on a vest.

I applaud the lazy comment above.

You can use chocolate spark plugs. Don't care a bit.

If you want to really impress your friends, get some Mobil Jet aviation grade turbine oil. Could be the coolest kid on the block. Mean while since the application is a lawn mower, dino-crap as you say works good for me. Zero oil failures. Your amsoil is crap compared to the Mobil Jet oil LOL. Wash that down with some juice.


slomo

 

[slomo]

Gaps were both .03 and with less than 5 hours they were already covered in carbon.

Could be a carb issue on a new 5 hour engine. ??

slomo

 

[Rivets]

Sir Mowzalot you can service your equipment with what ever parts and lubes you want, because if they work for you keep using them, but I do take exception with your comment and attitude about service techs and dealers. Your misconception as why they use certain products is totally off base. Good techs and dealerships don’t use subpar parts to keep customers coming back, that will ruin our reputation very quickly and most would be our ob business in short order. In fact the best ones really don’t want to see customers comeback because of a bad part. The small family owned business I just retired from has been around for 66 years with the founder still stopping in at the age of 96 about once a week. We use Champion plugs, dino-oil, and other products which you call “crap” when doing our service work. If these products are so bad, why would we have the reputation and awards of being the best service dealer in the area. I can tell you it’s not the service parts we use, but the quality of service our customers receive. Just because the businesses in your area have a poor reputation, don’t put us all in the same boat, you’ve got the corner on the 1% of the bad ones.
PS: I do agree with Slomo, as my 50+ years of work in this industry tells me that if a plug carbons up after 5 hours of use, you have a fuel/air mixture problem.

 

[SirMowzalot]

Sir Mowzalot you can service your equipment with what ever parts and lubes you want, because if they work for you keep using them, but I do take exception with your comment and attitude about service techs and dealers. Your misconception as why they use certain products is totally off base. Good techs and dealerships don’t use subpar parts to keep customers coming back, that will ruin our reputation very quickly and most would be our ob business in short order. In fact the best ones really don’t want to see customers comeback because of a bad part. The small family owned business I just retired from has been around for 66 years with the founder still stopping in at the age of 96 about once a week. We use Champion plugs, dino-oil, and other products which you call “crap” when doing our service work. If these products are so bad, why would we have the reputation and awards of being the best service dealer in the area. I can tell you it’s not the service parts we use, but the quality of service our customers receive. Just because the businesses in your area have a poor reputation, don’t put us all in the same boat, you’ve got the corner on the 1% of the bad ones.
PS: I do agree with Slomo, as my 50+ years of work in this industry tells me that if a plug carbons up after 5 hours of use, you have a fuel/air mixture problem.

I was just kidding. I have a family member with 40 years in the business as well. He gives me crap about my fanatical maintenance habits too. I've been that way since I let someone change my oil one afternoon, had a street race that night, won, but threw a rod in the process. Oh the sound gives me shivers. The dumb kid put 10w-30 dino in a 383 stroker during a hot summer. I owned it as my fault, and have done all my own maintenance and top end engine work since. If you want to laugh I actually looked to see if I could upgrade the ignition system on this thing with a motorcycle MSD kit, lol. Once the warranty ends of course. I'm just not your normal customer.

 

[Rivets]

You can say “I’m just kidding” after I called you out, but you can’t are back what you said. Good repair shops and techs are hard to find and when people who think they have all the answers, they make it difficult for us to help people who put their trust in us. With the attitude you portrayed do you really think I want to work on your equipment? No, I’ve got too many customers who trust me, that keep me busy even though I’m retired. Good Luck with your NKG’s, I hope you never get a bad one.

 

[SirMowzalot]

You can say “I’m just kidding” after I called you out, but you can’t are back what you said. Good repair shops and techs are hard to find and when people who think they have all the answers, they make it difficult for us to help people who put their trust in us. With the attitude you portrayed do you really think I want to work on your equipment? No, I’ve got too many customers who trust me, that keep me busy even though I’m retired. Good Luck with your NKG’s, I hope you never get a bad one.

You're kidding now, right? I assure you, you "calling me out" was never a second thought. You couldn't possibly matter less to me without pharmaceuticals. It's called stating the obvious. Most people got it the first time they read it, but with you I seem to have hit a nerve, lol. Folks can derive from that what they will but I've certainly seen enough to draw my own conclusions.