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[skreminegul07]

Regarding the attached picture:
These plugs were removed after the 1000 mile breakin of the replacement motor.  There are a nice tan, but the left plug (rear) has some pieces of material all over it.  I've never seen a pluglike this before.

Any ideas?

Thanks

[Deacon]

Just some pieces of melted metal from engine running so hot.

[skreminegul07]

Just some pieces of melted metal from engine running so hot.

Are you being sarcastic?    I hope so.

I replaced the plugs and will check again.

[sadunbar]

Regarding the attached picture:
These plugs were removed after the 1000 mile breakin of the replacement motor.  There are a nice tan, but the left plug (rear) has some pieces of material all over it.  I've never seen a pluglike this before.

Any ideas?

Thanks

Can you get a better picture of the plug on the left? 

Which cylinder is each plug out of?

[naitram]

kinda looks like like serious arcing happend, is the gap out of spec?

[sblade1948]

Looks like aluminum splatter from being to lean.

[110tHunDer]

Some info. on reading plugs here: http://www.theultralightplace.com/sparkplugs.htm
 
That rear (left) plug looks like it's got 50,000 miles on it the way the center electrode is worn.

[skreminegul07]

Here's a better picture.

I'm using a DFO Techclusion same set up as with the previous motor.  This is scary.  Plugs from the original motor did not look like this.

Click on the picture to zoom.

Thanks

[sadunbar]

Here's a better picture.

I'm using a DFO Techclusion same set up as with the previous motor.  This is scary.  Plugs from the original motor did not look like this.

Click on the picture to zoom.

Thanks

Melted center electode like that is generally pre ignition.  (Melted insulation is generally detonation)  Crap like that on the tip sometimes can be caused by bad fuel or additives (which would be on both plugs)

Was the plug tight?  A loose plug can look like that also (sucks cold air in and acts like a lean cylinder)

[skreminegul07]

Melted center electode like that is generally pre ignition.  (Melted insulation is generally detonation)  Crap like that on the tip sometimes can be caused by bad fuel or additives (which would be on both plugs)

Was the plug tight?  A loose plug can look like that also (sucks cold air in and acts like a lean cylinder)

Seemed tight.  It's not really melted but material is attached. 

[Boatman]

Neither  plug looks lean.  Maybe the timing is off?  I would keep both plugs, run new ones another 1,000 miles, and check again.  I would also use a torque wrench to tighten the new plugs.  Keep us posted and good luck.

[grc]

Hard to tell in the photo, but it looks like material has been deposited onto the plug, not eroded or melted from the plug.  Doesn't really look like the plug was overheated either.

Pulling this one out of my posterior, but I wonder if perhaps there was some casting flash or other trash (metal particles or whatever) left in the intake, head, or cylinder that wound up deposited on the plug.  Are the deposits metallic, or just hunks of carbon?

Jerry

[SE08RK]

Regarding the attached picture:
These plugs were removed after the 1000 mile breakin of the replacement motor.  There are a nice tan, but the left plug (rear) has some pieces of material all over it.  I've never seen a pluglike this before.

Any ideas?

Thanks

Looks like a too cold plug for the cylinder and its AFR. Problem is, the carbon build-up in the chamber is a self feeding problem and with the pre-ignition from an unbalanced compression between the two cylinders, this is going to get worse. If you haven't been using high octane fuel, you should be. And, try detaching the DFO for a while to see if it is causing an unbalanced fuel delivery problem. There are ways to detach all that carbon from the chamber but the loose carbon can cause some damage in the cylinder, rings and etc. not to mention polluting a muffler. Normal running will self clean the chamber to an extent but the over rich fuel problem must be solved first. Good luck with it....

[sadunbar]

Hard to tell in the photo, but it looks like material has been deposited onto the plug, not eroded or melted from the plug.  Doesn't really look like the plug was overheated either.

Pulling this one out of my posterior, but I wonder if perhaps there was some casting flash or other trash (metal particles or whatever) left in the intake, head, or cylinder that wound up deposited on the plug.  Are the deposits metallic, or just hunks of carbon?

Jerry

The material on the tip looks like deposits, doesn't it...  From bad fuel or trash from the initial build and start up.  But it is hard to see the electrode from the photo.  It almost looks like the electrode is melted (pre-ignition?), but it could just be the photo...hard to tell.

[FR8TRN]

Sustained Pre-ignition, which will usually look as a melted or missing center electrode and/or ground electrode as well as a destroyed insulator. Check for incorrect heat range plug, over advanced timing, lean fuel mixtures or even hot spots or deposit accumulation inside the combustion chamber.

You might wanna take a look back at the picture you posted and the one from the link someone else posted about reading plugs.  The center electrode on yours seems to be damaged, probably from the pre-ign, and the ground electrode is on it's way.  Your plug isn't as bad as the one in the pic, but it's headin in that direction.