Spark plug color disparity

[fedeskiff]

Hello fellow guzzists!

Last sunday while I was doing some maintenance on my V7 Classic 09, I removed the spark plugs to check the gap. Both gaps were matching the specs but I noticed a major difference color in both.

Left cylinder one, it's looking white. (I suspect this one sometimes misfire)
Right cylinder looks normal to me.





What could be the causes for this white color?
-Valves are set to 0,15 inlet and 0,20 outlet.
-Bike has been balanced a couple of months ago.
-Both spark plugs were BR8ES - NGK new at the same time.

thanks for the help!

Fede
 

[berniebee]

Have you noticed any driveability issues? Hard starting? Codes?

[Sye]

I'd change that sparkplug new or not. The ceramic centre looks almost perfect with no signs of running lean. Wouldn't be the first time a new plug was duff.

[John Croucher]

The relationship of the ground to the flame front.

[fedeskiff]

Have you noticed any driveability issues? Hard starting? Codes?

Just sometimes misfiring Idling when hot engine

thanks

Fede

[fedeskiff]

The relationship of the ground to the flame front.

Sorry John I did not understand your message.

Thanks

Fede

[John Croucher]

Sorry John I did not understand your message.

Thanks

Fede

Indexing of the plug relative to the piston dome.  The white ground is facing the top of the piston toward intake valve when it fires.  It burns the carbon off.  Mark the location of the ground, screw ithe plug back in tight and look at what direction it is pointing.  I have seen this white on one side of the insulation at the tip that faces the flame front.  The rest of the insulation around the tip will be black.  Look up indexing spark plugs. 

[Wayne Orwig]

Looking at those plugs, it is obvious.

Obvious that you need to put another 20,000 miles on them, and report back what they look like.

[fedeskiff]

I just heard that some spark plug caps of the first models of V7s were failing so I decided to replace mine.

I swapped the original MTA 5K ohm with a NGK LD05F-R.

I noticed that the plug is different and for the NGK I don't need the threaded adaptor (attached photo).

Is there any difference between this two different types?

Thanks

Fede





 

[Tom]

Make sure the connectors are on tight and the plug caps are also tight.  Switch the plugs and run them.  Like John says, install plugs so that they're installed in the same position.   

[73 sport]

  Fedeskiff, enter "Spark plug shims" on Google. There are several vendors selling these. The shims will allow you to orient the ground electrode in relation to the valves, slightly changing the flame front. Also try "Platinum" tipped plugs. Good Luck, Horst.

[fedeskiff]

Perfect I'll check everything on top!
After swapping the caps seems like the bike runs better and is more smooth, but it's hard to tell actually if its true.

One thing that I can confirm is that my left cyl is running hotter than my right one. I can see this by putting my hands when starts to warm up and also by the color of the pipes.

I guess this could be related with a lean mixture in the left one.

Is there any other thing that I can check away from Air leaks?

Thanks

Fede

[Dr. Enzo Toma]

A curiosity here, how much would it really matter which direction the ground electrode faces when both valves are closed during combustion and the sparkplug is not butted up against the cylinder wall? I've indexed spark plugs, but only on engines where it was necessary for clearance of high comp domed pistons.

[Wayne Orwig]

A curiosity here, how much would it really matter which direction the ground electrode faces when both valves are closed during combustion and the sparkplug is not butted up against the cylinder wall? I've indexed spark plugs, but only on engines where it was necessary for clearance of high comp domed pistons.

I believe the thinking here is to get the electrode to shield the ceramic from the cold intake air is all.

[Tom]

Take out all the variables to make sure that it's running right.  The OP now needs to check the carbs for correct settings for fuel consumption.

[Don G]

Maybe do a proper plug chop, WFO and shut it off with clutch lever pulled in, looking at plugs that have been idled and maybe started cold wont tell anything, if that's what happened to these plugs then they look normal.  DonG

[fedeskiff]

Thanks everyone for reaching and helping. I did some further maintenance today:

I checked the valves again and they still sit 0.15 and 0.20 (mm)
I inspected very closely for air leaks and spray manifolds and rubber hoses with Carb cleaner to see if i could notice any rpm difference but I did not.
I cleaned the lambda sensor and plugged back again.

After this I started the bike again and I can still confirm that my left cyl is much warmer than my right one. You can feel this difference just by hand.

My only remaining check it's to switch my injectors to see if maybe one it's failing..

Could this be a problem of the mapping? My bike was second hand and lacked some proper maintenance in a good dealer. So could be that the Maps are not updated as well. Unfortunately I couldn't find any historical recording of the versions so I can't tell if it's up to date or not. I can only see that in Guzzi Diag webpage there is V2.17

Thanks

Fede

[Beavis]

I just heard that some spark plug caps of the first models of V7s were failing so I decided to replace mine.

I swapped the original MTA 5K ohm with a NGK LD05F-R.

I noticed that the plug is different and for the NGK I don't need the threaded adaptor (attached photo).

Is there any difference between this two different types?

Thanks

Fede

You heard well ....

[John A]

Yep, two different types of plug ends for with or without screw termination.