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8V NGK Plug #'s

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FYI... the NGK plug that comes in the 1200 8V is a PMR8B (6378), and NGK USA states that it crosses with the NGK CR8EIX (4218) Iridium, which is more readily available and almost ~50% less.

From Steve below: The factory is now installing a NGK CR8EKB in the Griso 8V SE models, not the Iridium but a standard plug.
 
Todd,

The PMR8B platinum is the inner plug on the dual plug machines. Would you consider the iridium plug a suitable replacement in that application as well?
 
John, since NGK cross referenced it for me, I couldn't imagine a reason not to.
 
Just a note, The factory is now installing a NGK CR8EKB in Griso 8V SE models, not the Iridium but a standard plug.
This is a low priced plug.
 
V700Steve said:
Just a note, The factory is now installing a NGK CR8EKB in Griso 8V SE models, not the Iridium but a standard plug.
This is a low priced plug.
Click to expand...

It's also the same for the Stelvio.

Franck
 
I notice the NGK CR8EKB is a dual electrode plug.

According to NGK:
"Two ground electrodes allow
sacrifice of more material before
gap size becomes too large
therefore service mileage is
increased."

Regards,
David
 
V700Steve said:
Just a note, The factory is now installing a NGK CR8EKB in Griso 8V SE models, not the Iridium but a standard plug.
This is a low priced plug.
Click to expand...
So, has this been done to save money or improve performance? or both?
 
Goodvibes said:
V700Steve said:
Just a note, The factory is now installing a NGK CR8EKB in Griso 8V SE models, not the Iridium but a standard plug.
This is a low priced plug.
Click to expand...
So, has this been done to save money or improve performance? or both?
Click to expand...

Bean counters at work justifying their paycheck at the expense of a longer lasting and better performing Spark Plug for the Buyer. IMHO
 
draidt said:
Bean counters at work justifying their paycheck at the expense of a longer lasting and better performing Spark Plug for the Buyer. IMHO
Click to expand...
My HO too. Although there are situations where the simple plug unadorned with precious/semi-precious metal dots works best (e.g., Champion Copper Plus in classic British cars like TR6's).
 
mojohand said:
So in the Norge (and Griso and Stelvio) 8V engines, which plugs should we use?
Click to expand...

IMHO, back to square 1 (that is, Todd's original post above).

I've used NGK CR8EIX Iridium on my G8VSE for well over 20,000 mi (I replace plugs every 6,000 mi or so) with no issues whatsoever.
 
Iridium plugs are changed at 100,000 km intervals in Automotive applications, can't see why it would be any different on my Griso.
The 10,000 km interval recommended in the service schedule is a joke.
I will change mine at 100,000 km or if they start to misfire, whatever comes first.
I know manufacturers make all sorts of claims of improved performance for new plugs but after many 100's of plug changes over many years I have yet to experience an improvement in performance from fitting new plugs if the old ones were still functioning correctly. This especially applies with modern ignition systems.
I know they don't cost that much but why replace them if they are still ok.
Other may disagree.
Mark
 
Mark111 said:
...I know they don't cost that much but why replace them if they are still ok...
Click to expand...
Because the 8V engine runs so hot with the factory fueling, I prefer to stay on the super-safe side and change them more often. I recognize it may be on the anal side, but I don't care :mrgreen:
 
Greyo,
Anal or not if it makes you more comfortable about running your bike, then it is as good a reason as any for changing plugs more regularly.

Mark
 
Greyo said:
I've used NGK CR8EIX Iridium on my G8VSE for well over 20,000 mi (I replace plugs every 6,000 mi or so) with no issues whatsoever.
Click to expand...
Hell I still have the stock plugs in my '09 Griso approaching 18K miles and no fuel economy or runability issues . . . the gap hasn't noticeably changed. Might upgrade to the expensive plugs soon just because folks are so excited about them here. When I noted no change whatsoever in valve clearances at my last check I decided to skip that recommended interval too. CARC/gearbox oil replacement? Nah, not needed for a long time with the Pepto Bismol Redline in there. The excessive maintenance/replacement intervals are obviously meant to feed the dealer revenue monkey and that's fine. Just not for me.
 
I know this is a 4 year old post, but, I have a question. I bought the NGK CR8EIXs for my Norge 8V. Manual calls for a .6 - .7 gap. Out of the box the plugs were between .74 and .79. Should I gap them to .6 - .7 or leave them alone?
 
Rudy, With spark plugs it is better to gap them on the tight side. In use the gap opens up. That way they are in the correct gap range longer.
 
True, but I have put over 30,000 miles on Iridium plugs in another bike and saw no noticeable gap increase. As I stated in the other thread I figure NGK can keep the two surfaces closer to parallel than I can and they designed the plug so I default to their recommendations. I think any of the above specs will work to the point of no noticeable difference. The fine wire requires less voltage to spark so it can handle a larger gap is my thoughts. Larger gap, in theory, means a better ignite of the fuel.
From a UK web page:
Q14. Should I regap my Iridium spark plugs?

In most circumstances, no. The nature of Iridium spark plugs means that they are able to utilise a larger gap setting while actually requiring less voltage and straining the ignition system less. If you *have* to regap Iridium spark plugs (e.g if misfire occurs due to gap being too large) then do so with extreme care. Do not use a slide type gapping tool or put pressure on the brittle centre electrode as it may become damaged.

Q15. How do I regap my spark plugs?

To open the gap, use a pair of fine nosed pliers or a specialist gapping tool (not slide type for Iridium or other fine wire types) to carefully bend the ground electrode outwards, away from the centre electrode. Take care not to contact the porcelain insulator or the centre electrode as they can be easily damaged. Use a feeler guage to check for the correct gap size - it should be a light sliding fit. To close the gap, tap the ground electrode gently on a hard surface and then open the gap to the required setting using the method described above.

sparkplugs.co.uk/faq/
 
Resuscitating this old thread with a little more information.

Context: I have been chasing a stumbling that has been very annoying and throws no codes. It MIGHT be due to a vacuum leak around the left throttle pivot that Todd diagnosed on a visit a year ago, but I want to make everything ELSE right.

So, on this earlier than usual plug change, I measured the gap. I also looked up the NGK nomenclature to see if there was an official factory gap. According to their specifications chart, plugs without a number at the last digit of the plug code are 0.8-0.9mm gap if intended for cars, and 0.6-0.7mm for motorcycle plugs. So exactly what the factory requires.

My new NGK CR8EK’s are very consistent on all the electrodes. They measure 0.65 mm gap on my metric feeler gauges, the 0.026 inch gauge that is 0.66mm will not pass.

The old CR8EK’s with just under 2,600 miles will all pass the metric 0.8 feeler, and three of the four electrodes will pass the 0.032 inch/0.813mm.

So if the old spark plugs were made as consistently as the new ones, they started right in the center of the spec range, and were out of tolerances in less than half the standard service interval. Maybe there’s something about the 8V motor that makes it worthwhile to use the iridium and change them at the spec intervals? I am going to try them next service.
 
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