Spark Plug Analysis

Royse

Well-known Member
These are brand new plugs, ran about 3 hours in a freshly rebuilt
V-Twin lawn mower engine. I pulled them just to look.
Spark jumps a small engine gap on a spark tester at each plug,
So I think the coils are good and adjusted correctly.

What do you think? Rings just not seated yet or a valve adjustment or?

884.jpg
 
What type of plugs? I would recommend NGK BPR6ES plugs on a twin V
Briggs. If you want life time ask them to cross into the NGK Iridium
plugs. Work fantastic. Also a dab of copper never seize on the
threads. Could be oil usage. Switch to synthetic blend 5 - 20. after
break in. Synthetic will not burn like that. Your valves should be
.004 intake .006 exhaust. Letus see what others have to say.
 
Thanks Jeffcat, this is a Kawasaki, not a Briggs.
Guess I should have mentioned that!
I have a new set of NGK to switch to after break in, had to
order them. These are champions because that's what they had.
They are the recommended plugs from the manual.
 
I had issues with a 20 hp kohler command. One cylinder would foul plug like yours on the right.
Other cylinder looked like your plug on left. I would switch plugs around and the good cylinder
would clean carbon off plug while the bad cylinder would dirty it up again. Did the switch every
10 hours.

Boys at repair shop told me that could be either a bad head gasket or burnt valves.
I did a compression test and leak down test. Both tests showed nothing wrong.

Then I bought new head gaskets, removed just the head on bad side, lapped in exhaust and intake
valve. Problem solved. I didn't have to worry about valve adjustments. Kohler command has
hydraulic valves.

My point, compression tested the bad cylinder. It was only a few pounds below the good side, yet
under running conditions the bad side didn't have enough compression to run hot enough. Before
valve job, I purchases an IR thermometer from HF and exhaust temps on bad side were 200 degrees
less than the good side.

BTW, both my cylinders used same carb, which has no adjustments. Did you grind valves?

Let us know what you find
 
You have had good luck with NGK? I used a set them in a 24HP Kohler Pro engine and a Brigg & Stratton 20HP Vanguard. I didn't get the hours out of them like I did out of Autolite plugs. The Kohler didn't perform well with NGK and replaced them with Autolites. Only trouble with Autolite is that auto supplies around here are not stocking Autolites you have to order them.
 
OK very good Kawi engines. Champ plugs are the worst you can use. See
what a whole lot of other guys have said. Engine can also be running a
little rich but that would usually give you gray deposits. Give
yourself at least 25-50 hours of run time to see what settles in. Both
of my Briggs Vtech engines and all three of my bigger generators have
NGK Iridium plugs. So does my Ford Expedition. Can't praise them
enough. Cosssssty but worth the money. After first startup in the day
my Briggs Vtech engines go BIP. RUUUUUUUUR. AS Soon as you turn the
key. They barely make one revolution. Please try them fersure!! By the
way, make sure you didn't overfill your crank case. My Vtech engines
can go from 1 1/2 gt. All the way to 2qt. Of oil. Depends what oil
filter you use. Get back to us.
 
Another thing with those single body carbs aka balanced carbs. They work great when they work but when they go out of balance you are toast. Is your carb a NIKI carb? Went over this in the garden tractor section a couple of weeks ago and told the guy to buy a new carb on fleabay. He was shocked how well it worked. They are third revision models and are supper sweet how nicely they work for around $50.oo. This is on my Briggs engines and don't know what you have but look into it.
 
Well the NGKs work fine for me but as of about a year and a half ago I did a total switch over to irridium plugs. Very happy how they work. You can also get Denso plugs that way. The iridium plugs are supposed to be hi-performance plugs. Even my little tiny 800 watt crappy 2cy. Generator works beautifully with one of those plugs. Give a set a shot and see what you think. Come to think of it.....maybe I will screw one of these into my big bad Mc Culloch 650 professional chainsaw. Hummmm.
 
I use the NGK in my Chainsaws and they seam to last forever. I put a set of Ngk plugs in my IH one ton truck years ago. I had a buddy that worked at an auto supply and he said that they were good plug. I put them in the truck in the middle of winter and had trouble starting truck in cold weather. I only left them in 2 weeks and took them out and replaced them with new AC Delco plugs and it started great in cold weather.
 
jeffcat,
Not sure if my carb is a NIKI carb. Carb wasn't the issue, it was a valve issue. One carb using the same intake manifold. All is well after I lapped both valves on just the bad head. Didn't do anything to head on good cylinder. Engine now has 1800 hours on it. It running clean and strong.
 
"Did you grind valves?"

Yes sir. The machine shop I've used for 10+ years did the heads,
valves and block. It seems to run fantastic, but it did have a carb
issue. Single carb on the manifold. Kawi FH680V-CS10.

After fixing the carb issue, I pulled the plugs and just didn't like
the looks of the plugs. Doesn't look like it was caused by the carb
problem to me since it was a stuck needle/no fuel issue.

For now, I have swapped the plugs side-to side.
Engine is running fine.
I'll pull them after a few more hours and see what they look like.
 
"Champ plugs are the worst you can use."

Everything changes over the years.
I remember back in the day I could put Champs in a Dodge or
Ford and they would work great. Put them in a GM and they were
junk. I've never understood why, but that's how it worked.

I would never put Champs in my motorcycle. NGK or Denso.
They just didn't work well or for long. Again, don't know why.

But, that's what they had, so I bought them for break-in while
I waited on the NGK's to get here and will replace them.
I might try the Iridiums. There's only two plugs.
 
I wont allow Champion plugs in my shop. Worst things you can buy. I installed five one week all five failed on the first run. My brother bought a weed eater. Couldn't get it to start. I pulled the Champion out installed an NGK. Fired right up. They used to be one of the best. But no more.
 
The one on the right looks "oil splashed", could be that cylinder is passing a little oil, may seat in time.

The mixture looks good, heat range looks good, nice brown color.

Gap looks a little wide.

I would switch them, see what it does, check the gap specs. It will probably clean itself up unless it's oiling really bad.
 
I understand the sentiment Billy, production has moved.
I'll see what they look like after swapping side to side.
I do not believe this is a problem with the brand of plug.
If swapping proves that it is a bad plug, then I'll believe it.
 
(quoted from post at 22:46:37 07/22/17) "Champ plugs are the worst you can use."

Everything changes over the years.
I [b:a1afea464d]remember back in the day I could put Champs in a Dodge or
Ford and they would work great. Put them in a GM and they were
junk. I've never understood why, but that's how it worked.[/b:a1afea464d]

I would never put Champs in my motorcycle. NGK or Denso.
They just didn't work well or for long. Again, don't know why.

But, that's what they had, so I bought them for break-in while
I waited on the NGK's to get here and will replace them.
I might try the Iridiums. There's only two plugs.

My experience as well. Mopar came stock with Champions, Ford had Autolites, and GM AC plugs. The plug companies had a mission to build a plug that worked in the associated OEM.

So we always used what the factory installed. Seemed to work best. Bosch in the german, NGK or Denso in the Jap, Champion in anything else.

I worked with a guy that had an '80 Alfa Romeo spider. He tried all the plug brands and never could get the plugs to last. Finally he got a set of Lodge, british plugs, and that fixed it. He found the Lodge advise in a shop manual he'd just bought.

30+ years ago, Champion had Gold Palladium plugs, same thin wire electrode as the Iridium style. Haven't seen them for decades, but if I had a difficult to R+R a set of plugs, that's what I'd use.

Up until the mid '80s, Champion was probably the most developed of the plug makers. I bet they got bought by something bigger and they ------ all that away.

TRIVIA; What does the AC on those plugs represent???? NO web searching; you either know it, or you don't. Trivia was a lot more fun before the net....
 
well, now that we had dished Champion, gave our opinions etc. and etc..

Neither of those plugs look terribly bad to me. Even though there are some deposits on the right plug, it looks like it was still firing. Maybe Put them back in and run them.

Are you running 93 octane? Are you running ethanol blend fuel? How old is the fuel in the tank? All have an effect on how the sparkplugs look after being run on them.

And a lot of people's problems with Champion plugs actually should be blamed on old, bad fuel. Champion is OEM in about half the engines Kawasaki sells right now. Would they not have put NGK or Denso, or whatever in if they were really better?
 
When I was growing up. It was Champion or Auto-lite plugs. Some did use Delco. But the local garage in Grapevine Tx. Used Champion or Auto-lite. Owner
wouldn't use anything else. Used to be top of the line. Now Champion is junk and Auto-lite has to be ordered.I recall a man coming in one day told the
mechanic he wanted a certain brand of plug and nothing else would do. Owner came back from lunch was told what the car owner said. He had the car
shoved across the street to an empty lot. With a note on what he could do with his car.

I learned allot from that old man. He was always willing to teach the kids about being a mechanic. But no one told him how to run his shop.
 
Hello Royse,

It looks like the dark plug has a smaller gap. Compression and air to fuel mix also will effect
combustion. I would check the valve clearance as well. Gap the plugs @.035 if it is a magneto setup. You
can go more on solid state ignition.

Guido.
 
Well, in the great spark plug debate, I can offer some anecdotal evidence.
Years ago, a friend of mine called upon me to rebuild his carburetor on his Datsun pickup. He said that he had just tuned it up, and it did not run right. So, I rebuilt the carb. When I put it back together, it did not run any better. I went over his work. I found nothing wrong. So, I asked him how it ran before he worked on it. He said it ran fine, and this was just for maintenance. So, we tried the old plugs back into it. Suddenly it ran good again. The new plugs he had put in were Champions. We got a new set of NGK plugs, and it lived happily ever after.

Next case. A customer brought a nearly new Mustang into the dealership I was working for. The complaint was that it ran poorly. Since the car was under warranty, it landed in my bay. So, I performed all of the requested diagnostics - including hooking it up to the SBDS system. Everything showed normal. No problems found. Yet, the engine did run noticeably rough at idle. Next, I took out a spark plug. It was a Champion. I asked about this, and was told that he had just had the car tuned up. I went to the parts department and got a new set of Motorcraft plugs and installed them. Engine ran smoothly. I demonstrated to the customer, and his comment was that it was now running properly and to his satisfaction. He asked me what I found. I handed him the Champion plugs and fold him what I had done. He became angry, insisted that I put the Champions back in, and was headed back to the garage that had done the tune up.

Over the years, I have had several times encountered similar situations. I found that Champions work perfectly in Chrysler products, but not as well in other makes. I also found that Autolite or Motorcraft plugs work best in Ford products. AC plugs for GM cars. Also, Champions work well in my 1954 Packard. Go figure...
 
I figure you do the best you can and install OEM parts or parts from a OEM supplier for that vehicle...

Autolite has paid the price for selling there soul to China... Autolite can go straight to ell if you want my opinion...

One that seams to be a problem is Champions if I go there on a Mopar I get them from the dealer...

I may be the only dumb MF'er around that orders all my coolant hoses from OEM dealers... As soon as they here my voice they say let me guess you want all the hoses :D

Worst case you did the best you could do to make it last as long as the original did...
 
IMHO, dunno WHY you would pull the plugs on a rebuild after only 3 hours, unless there was an obvious issue.

IMHO, at that point their appearance is MEANINGLESS, about like checking the compression on an old tractor that's just been started after a 30 year "rest". If it's running OK with no obvious issues likely to make it grenade, run it for fifty or a hundred hours to fully break it in, then have another look, if you feel you need to.
 
"I found that Champions work perfectly in Chrysler products, but not as well in other makes. I also found that Autolite or Motorcraft plugs work best in Ford products. AC plugs for GM cars. Also, Champions work well in my 1954 Packard. "

HOW do you suppose the engines or sparkplugs "know" when there is a brand mis-match? Are there RFID chips and a a dedicated little 'puter that detects this?

Curious "minds" want to know!
 
I will agree with the others, NGK BPR5ES, or 6ES if you want a cooler plug. I have over 30 small engines,
mostly Hondas buts a few BS, Kohler, Kaw, stihl ect. I don't like Champion at all. Everything runs better with
the NGK except my old Johnson outboard....it will only seem to run on Champion, and occasionally a Bausch in the
chain saw answer weed wacherry.
They get replaced yearly regardless of brand, changing plugs is cheap and I need everything to run smoothly.

To answer your question about the plugs in the picture...I don't know, if it was running fine I would leave them
alone, but I would just change the plugs next time to NGK
Good luck Grant
 
We have found that we get more performance and HorsePower out of copper or silver tipped plugs than any other material but don't get the life out of them like the tips made of other materials.
 
Hey Jeff,

The carb you put me onto for my 22 hp BS is working fine. No regrets. Put in some NGKs also. Thanks again for the tips.
 
I revisited this post after thinking about it for awhile per my first visit.

My previous 2 road pickups were an '07 4.7 and an '09 Hemi Ram. Both ran Champions. Both were a PIA to change plugs. Recommended
change interval was 30k miles. They were the normal copper tipped plugs you buy for a couple of bucks. Engines ran fine, no complaints.
What got me was that Chrysler-Damlier couldn't find it in their heart to install an iridium plug like my current Silverado that are listed in the
owner's manual to go 100k miles on OEM equipment. Really chapped me the whole time I had them. Stories floated around the www that
the engines were tuned for that plug and nothing else would work....after reading this post there may have been some truth to that rumor.

I had an ulterior motive in mind. 30k on the plugs, for a non-do-it-yourselfer, considering the majority of owners (cowboy Cadillacs...lots of
them here in TX.) would drop their trucks off at their local Ram dealer to have them installed. Wink!
 
Make up of the metal in plugs. You would think about any modern engine could run any plug if installed correctly. I know my older Fords with the 4.6 engine could not and would not run platinum plugs - needed to have autolite copper tops or you would be stuck with a constant miss.
 
Me too, have Champions in 4 garden tractors, another one I mow 4 hours a week with got NGK this spring just to see what I was missing, ran perfect on 5 year old Champs, don't run any better now. Both Farmalls, chain saw and trimmer along with 2 tillers have Champs, I don't see the big deal with NGK plugs, think that's what's in my Snowmobile and that's the hardest starting thing I ever had.
 
"IMHO, dunno WHY you would pull the plugs on a rebuild after only 3 hours"

Yep, I know that was early Bob. Pulled them to look because of the
carb problem that is now fixed. I wanted to see if one was fueling
and firing differently than the other. I didn't expect oil like that.
 

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