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Spark plug gap??

9K views 46 replies 10 participants last post by  silvervtx04s 
#1 ·
What should I set the spark plug gap at on a 02 1800 C? They are pre gapped but I bought the NGK 6341 instead of the 6502. They are cheaper by $3 a piece. Don't know what these come gapped at but they sure look narrow.
 
#5 ·
-You don't set gap, you check it. The gap is 'set' when the plug is made. In the old days when plugs were cheaply packaged they'd get knocked around in transit and the ground electrode would get bent. Now better plugs come with a protective sleeve. Al your doing when you check the gap is insuring that the surface of the ground electrode is parralell to the center electrode.
 
#7 ·
dbx said:
If your buying plugs other than OEM, the mfgs. gap may be set for something other than what the X ignition calls for. In that case you should check, and set, if neccessary.

Exactly, this is the case for the 6341 plugs. They were gapped at about .037 out the box. For a diff. vehicle. I set them to .040 and let em rip!
 
#10 ·
dbx said:
If your buying plugs other than OEM, the mfgs. gap may be set for something other than what the X ignition calls for. In that case you should check, and set, if neccessary.
Yet another good reason not to run a plug other than the IFR5L11...

Yes, a little never-seize on the threads of your plugs is a good idea.
 
#11 ·
birdiemn said:
dbx said:
If your buying plugs other than OEM, the mfgs. gap may be set for something other than what the X ignition calls for. In that case you should check, and set, if neccessary.
Yet another good reason not to run a plug other than the IFR5L11...

Yes, a little never-seize on the threads of your plugs is a good idea.

Whats wrong with regapping a plug? I think it would be worse to NOT regap these plugs and install them with a .037 gap.
 
#12 ·
You'd probably never notice a difference, .003" is a strand of fine hair. I run Nology ign., and they rec. .035" for a fatter, more concentrated spark, and it runs great, plugs burn nice and clean. Stock Ign., stock gap. I use anti-sieze myself, good job!
 
#13 ·
I'm not a believer in installing an inferior plug that may not work as well and probably won't last as long. The OEM plug for an '02 was the IFR6L-11, they were changed to the IFR5L-11 (a slightly hotter plug) in the '03 and newer models.

These iridium plugs usually last a long time. They can be cleaned with carb cleaner and a toothbrush, and if the electrode and gap are good there's no reason not to reuse them. I've had my current ones in there for 16000 miles and they look great and gap out perfect.

Tests have been run that find the OEM recommended plug to be superior to it's cheaper replacements. Why compromise on something that is essential to the motor's proper operation to save a total of $12 every few years? It doesn't make sense to me, but, I can only speak for what I do with my bike and for my own opinions. YMMV. :wink:
 
#14 ·
It is a no brainer to check the gap.
At most it adds four minutes to instalation.

I always check the gap and INDEX the plugs.
May help may not,but as an old hot rodder from 50's and 60's it makes sense to direct the flame path toward the intake valve.
 
#17 ·
240VTX said:
I would not have bought these if it were not NGK Ideneron's. The $10 plugs only diff. was a laser something or another and the gap size.
If you do a bit of searching you can find the answers to almost any question on this forum. That's not the only difference between those plugs...

Tapper said:
For now, I'll recommend the following two plugs:

NGK IFR5L11
NGK IFR7L11 (10.5-1 compression)
Denso VK16PRZ11
Denso VK22PRZ11 (10.5-1 compression)

Note: Many dealers have been recommending a different NGK plug, however, NGK says that plug is the wrong resistance, and recommends the above noted plug - which agrees with the service manual exactly.
The other difference you may not have noticed is the IFR5L-11 plugs have a platinum ground vs. a steel ground on the BKR5EIX-11. I believe this is what creates the resistance difference and changes the spark.
 
#19 ·
The less resistance the better, especially w/stock plug boots, which have plenty of resistance already. I run non-resistors without a problem, and they stay cleaner also. As long as there is enough resistance to keep EMI, and RFI at bay, which the stock boots have, your better off with as little resistance as possible in your plugs.
 
#20 ·
birdiemn said:
I'm not a believer in installing an inferior plug that may not work as well and probably won't last as long. The OEM plug for an '02 was the IFR6L-11, they were changed to the IFR5L-11 (a slightly hotter plug) in the '03 and newer models.

These iridium plugs usually last a long time. They can be cleaned with carb cleaner and a toothbrush, and if the electrode and gap are good there's no reason not to reuse them. I've had my current ones in there for 16000 miles and they look great and gap out perfect.

Tests have been run that find the OEM recommended plug to be superior to it's cheaper replacements. Why compromise on something that is essential to the motor's proper operation to save a total of $12 every few years? It doesn't make sense to me, but, I can only speak for what I do with my bike and for my own opinions. YMMV. :wink:
+1 What he said.

KeyWasted
 
#23 ·
I use a copper formula that's good for +2000 degrees. It's safe for everything from O2 sensors, to header bolts. Versa Chem type 13. I think any hi heat formula will do, read the label, it should indicate uses. If it's, oxygen sensor safe, it's certainly good enough for spark plugs.
 
#24 ·
240VTX said:
Just took my bike for a ride with the 6341's (instead of the 6502's) and it runs great and much smoother than the NGK standard cold plugs that were put in it by the Honda dealer. All's good.
First of all, please understand that this isn't just directed at you, it is documenting some facts for posterity. Somewhere along the way someone will search "spark plugs" in the tech forum and they will read this thread. I just want to make sure that they can read enough to make an informed decision.

Many have found that the IFR6L-11 plugs that were standard in the '02 bikes would foul out some. That is why Honda switched to the hotter IFR5L-11 on the '03 and newer bikes. If your old plugs were fouled and in need of cleaning or replacement, most any new plug you put in will feel better initially. What you won't notice is the gradual loss of performance due to the higher resistance and therefore colder spark in the cheaper plugs. If you have to replace it more often it doesn't really save you any money. :wink:

If, on the other hand, you intend to actually toss them in the trash and replace them every 8,000 miles then you may come out ahead, only dealing with a minor performance loss and possible a loss in MPG. That loss could, however, offset your entire savings on plugs and more.

Now, all that said, as Johnnycheese has pointed out in the past this is all moot if you go get a custom fuel map done on your bike with those plugs in. You could run that motor smooth on some 99 cent a piece Champions if you found ones that fit and had a custom fuel map done, although your peak performance would probably be commensurate with the cost of those hunks of steel. That said, since the majority of riders are not running a PCIII with a map customized to their bike and whatever plugs they have decided to run to save a buck or two, you can lose performance, gas mileage, and plug longevity by switching to a lesser quality plug than the ones that are recommended for the engine.

So here's my simple point: you can clean and reuse the IFR5L-11 plugs as long as the electrode is in good shape and the gap is in spec. You can get these plugs for $9.99 each at O'Reilly's. Let's say, conservatively, that you only run them 16,000 miles (I'm at 16,000 on mine now and they're still going strong). That's $40 every 16,000 miles. Now let's say that you run the BKR5EIX-11 at $6.99 each, but they have to be changed every 8,000 miles. Now you're spending $56 on plugs every 16,000 miles, plus you have potentially lost fuel efficiency. Even if your gas mileage only dropped 2% (which you probably wouldn't even notice without keeping very close track of your fill ups) you would be out another $30+ in increased fuel use. So how much are you really saving?

In the end, it's your bike so whatever makes you feel good is best for you I suppose. Being a tech guy who troubleshoots problems and recommends maintenance and repairs as part of what I do for a living, I am hard pressed to ever recommend to a customer an inferior quality replacement part. I take the same attitude when it comes to my bike. I'm all for saving money, but you have to consider whether an initial minor cost savings really saves you money in the long run. I'm not sayin', I'm just sayin', you know? Food for thought, and as I said before: your mileage may vary (especially with cheaper plugs). :D
 
#25 ·
"Now let's say that you run the BKR5EIX-11 at $6.99 each, but they have to be changed every 8,000 miles. Now you're spending $56 on plugs every 16,000 miles, plus you have potentially lost fuel efficiency."



I understand it's not directed at me. It's ok. But your statement above is not ture. I also will run these plugs as long as there is no wear and the gap is correct. These should be as good as the 6502's. They are Iridium's also so they should last as long. Won't be changing every 8K.
 
#26 ·
240VTX said:
"Now let's say that you run the BKR5EIX-11 at $6.99 each, but they have to be changed every 8,000 miles. Now you're spending $56 on plugs every 16,000 miles, plus you have potentially lost fuel efficiency."



I understand it's not directed at me. It's ok. But your statement above is not ture. I also will run these plugs as long as there is no wear and the gap is correct. These should be as good as the 6502's. They are Iridium's also so they should last as long. Won't be changing every 8K like the 6502's.
Two problems:
1. The plain steel ground will corrode faster than the platinum one.
2. The plug burns colder than the IFR5L11 recommended so it will likely foul faster and have to be replaced sooner if it can't be cleaned off.
 
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