Never used a XC Always replaced with the RC12YC and the later BKR5E/CS6 since having multiple failures of Champion plugs I avoid them if all possible. The XC plug was discussed years ago at one of my engine update schools and since nobody stocked the XC plugs at that time were told to just use the RC plugs.
Champion XC12YC - NGK Equivalent
- Thread starter shurguywutt
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Hammermechanicman
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When champion moved production to south America they had problems with plugs arcing intrernally but that was resolved years ago. I put in over a hundred champion plugs a year in mowers without any issues. But i still like NGK BPMR7A in chainsaws.
I ;purchased 6 Champion plugs this year because my normal NGK was out of stock at all my suppliers. All 6 plugs failed with an hour of installation.
Hammermechanicman
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Wow, i buy my plugs in shop packs from stens and i have installed a few hundred over the last few years and none have failed. Is it possible you got counterfit plugs? Many thousands of new engines come out every year with champ plugs in them that don't fail. Briggs has their own part number for plugs and they are champ brand. I have had a couple new NGK plugs fail in short time in a couple honda engines which i thought was odd and they were from stens also.
This was from a OEM parts supplier that didn't have the BPR4ES in stock and auto subbed to the Champion equivalent. There was period a few years back that briggs was using that special .020 gap plug that I was changing one under warranty about every week. That plug would quit right in the middle of somebody mowing their yard, and if you subbed to a .030 gap plug it would cause a misfire.
My dealings with Champion have been less than stellar over the years. Lost a shop pack of J19LM that would fail within minutes of installation. The RN14YC equivalent to the BPR4ES plugs that wouldn't restart hot, and the 4 D21 plugs I had to order for another project I am working on that had the plug gaps slammed shut like that had been dropped on their noses before boxing because the boxes were undamaged.
Have had a few BPMR7A go bad in chainsaws within a few minutes of running but that was maybe 2 or three out of a couple hundred of that plug.
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I quit using champions. I had 3 fail last year.
I'm mainly using NGK or Autolite plugs now.
Started doing research after the J19LM case of plugs failed and found a reference in a Champion plug application catalog that stated that a 25% misfire rate was acceptable. And don't ask for the reference because that catalog is long gone, and I haven't been able to find that reference since.
Maybe that is the reason that a lot of vehicles have multiple plugs per cylinder.
bertsmobile1
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Interesting
It might be a fuel difference but the 2 Titans I service will not run on anything other than the XC's
They both start fine cold & run fine for a short while then they start to miss and it is a lean-over advance miss
The engines then overheat.
I tried to increase the gap to slow the timing down a poofteenth and if the gap is big enough to run properly, then it is almost impossible to start
Both of them ran perfect on the XC's so it is a no brainer for me , use the dearer plugs ,
It might be a fuel difference but the 2 Titans I service will not run on anything other than the XC's
They both start fine cold & run fine for a short while then they start to miss and it is a lean-over advance miss
The engines then overheat.
I tried to increase the gap to slow the timing down a poofteenth and if the gap is big enough to run properly, then it is almost impossible to start
Both of them ran perfect on the XC's so it is a no brainer for me , use the dearer plugs ,
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Had 2 RC12YC fails....... One would Run for 10 minutes, then start backfiring and blowing some black smoke out of the exhaust. Put a NGK plug in it and it was fine. The other ran for 20 minutes than quit, and wouldn't spark.
the third was a J19LM that was bad right out of the box apparently.
bertsmobile1
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Back in my college days I worked in a Champion plug factory
That factory made every brand of plug that was currently available except Bosch.
Each & every plug got tested and graded as they came off the end of one of the machines
In fact the tester did about a dozen tests .
So I always doubt the "bad out of box" stories
However a plug can go bad in an engine from 1 single bad engine cycle
Once a spark has tacked down the sides of a modern plug that does not have the lead based glaze on the insulator there is nothing that can be done but to replace it.
While plugs can in theory be damaged in transit, that damage ( rust , corrosion or mechanical damage ) should be evident on both the plug & the box
That factory made every brand of plug that was currently available except Bosch.
Each & every plug got tested and graded as they came off the end of one of the machines
In fact the tester did about a dozen tests .
So I always doubt the "bad out of box" stories
However a plug can go bad in an engine from 1 single bad engine cycle
Once a spark has tacked down the sides of a modern plug that does not have the lead based glaze on the insulator there is nothing that can be done but to replace it.
While plugs can in theory be damaged in transit, that damage ( rust , corrosion or mechanical damage ) should be evident on both the plug & the box