gapping iridium plugs

[scoopfraser]

I just bought a set of NGK DCPR7EIX plugs and noticed they recommend not to alter the gap due to the fragile iridium electrode.  Both plugs are close to 0.030" which is not quite where I would like them to be (0.035").  For the guys that have used these plugs, did you carefully gap them or run them as-is?  These plugs are going in to a high-compression 95" Underground build...

Thanks,
Sean
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[Ram]

Very carefully. You don't even want to touch the gap where the spark jumps. Have done it only a couple times though. Don't know if its even worth it.

[Sixspeed]

Here is the NGK web site. Click on #3 for the gapping video. They show the proper gapping technique for iridium plugs.

http://www.ngksparkplugs.com/tech_support/spark_plugs/installation/index.asp?mode=nml#gapping

[WhipLash96]

I have always gapped them myself with no issues.

[scoopfraser]

Thanks for the quick responses!  The method shown in the video is how I've always gapped plugs so I guess I was over-thinking it.



Sean
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[trex]

So what would be a good gap to run on a 95 incher with 10.5-1 compression? I am running the NGK plugs also and never checked the gap but the bike runs good. But will check the gap from now on with new ones.

[springer31]

DCR8EIX for high compression
DCPR7EIX for stock compression

[scoopfraser]

Trex, from my searching the board it seems like 0.035" would be appropriate for your situation.  Also, as springer mentioned, there are different heat ranges to consider as well.  As far as NGK goes, 7 is the o.e.m. heat range equivalent whereas 8 would be colder and 9 colder yet.

Sean
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[trex]

Bought some DCPR8EIX NGK's this morning after checking with a NGK tech from their web site. He also reccommended those plugs at .035 for a hi comp. HD. My luck they are at .030 like scoopfraser's are. I watched the NGK video on gapping and they make it seem real simple, well I bent the tool trying to gap at .035 and didn't even move the frikin thing. Whiplash96, you say it's simple, give me a clue. I put the gapping tool in the elbow of the plug making sure not to touch the electrode and could not get the arm to move.

[attachment removed after 60 days by system]

[glens]

Did you try to change the bend of the elbow or the strap between the base and the elbow?

[FSG]

You can put a suffix on those NGK Plug Numbers which specifies the gap in tenths of a mm.

A DCPR7EIX-9 has a 0.9mm (.0354") gap, other sizes available are -10, -11, -12, -13, -14, -15

Note: NGK do not recommend gap adjustment for precious metal spark plugs so it'd be best to get the correct plugs from the start.

[trex]

You can put a suffix on those NGK Plug Numbers which specifies the gap in tenths of a mm.

A DCPR7EIX-9 has a 0.9mm (.0354") gap, other sizes available are -10, -11, -12, -13, -14, -15

Note: NGK do not recommend gap adjustment for precious metal spark plugs so it'd be best to get the correct plugs from the start.

Well that's nice to know, sure didn't see it on their web site nor did the tech tell me that. They also show how to gap on their site, even though it didn't work with the tool they showed. I did get it to .035 with a large pair of needle nose pliers placed in line with the ground electrode.

[Sixspeed]

Bought some DCPR8EIX NGK's this morning after checking with a NGK tech from their web site.  I put the gapping tool in the elbow of the plug making sure not to touch the electrode and could not get the arm to move.

The gapping tool you have is a little different from the one on the video. Try a different one. The video does show the tool placed closest to the base of the spark plug. It does take a strong pull. As to the issue of not gapping it is probably a litigation issue not to have just any yo ho try to gap with the wrong technique or tool. Otherwise, they would not have a video showing how. Just my opinon.

[trex]

You can put a suffix on those NGK Plug Numbers which specifies the gap in tenths of a mm.

A DCPR7EIX-9 has a 0.9mm (.0354") gap, other sizes available are -10, -11, -12, -13, -14, -15

Note: NGK do not recommend gap adjustment for precious metal spark plugs so it'd be best to get the correct plugs from the start.

               "The DCPR8EIX isn’t offered in a -9,10,11. Its only offered as the DCPR8EIX, but you can adjust the gap on it with a bar or wire style gap hook"

That was from the NGK Tech I emailed asking about the different suffix's after your post.Also told him the adjustment was made with pliers as thier preferred way didn't work.

[FSG]

then you could try the DPR8EIX-9 which has an 18mm Hex rather than a 16mm.

[trex]

then you could try the DPR8EIX-9 which has an 18mm Hex rather than a 16mm.

Are you an ex NGK tech? You know more than the guy at thier web site. What is the gap on that -9, FSG? That Hex your talking about, I use a 5/8 socket,didn't think they were metric.

[FSG]

Are you an ex NGK tech? You know more than the guy at thier web site. What is the gap on that -9, FSG? That Hex your talking about, I use a 5/8 socket,didn't think they were metric.

No, just have a few catalogs (NGK, Bosch) on the shelf,     and I use NGK plugs in everything, cages down to lawnmowers.

5/8"  =  15.875mm  close enough to 16mm   

a -9  is  0.9mm / 0.036"

[trex]

Thanks FSG, the 9 sounds like the one then. I installed the new ones and it runs good but I sure didn't like gapping them with the pliers.