Optimax 200 spark plug

[kostas74]

I was checking my optimax's spark plugs and i was wondering is this how it should look?
This is from cylinder #6, the rest ones are half white half black.

[kostas74]

Is there a chance the engine is running lean?

[XstreamVking]

My 2004 opti had a coil that was double firing and eating up the #6 [plug. The dealer replaced some or all the coils under warranty and I haven't had the plug get eaten since. There would be no electrode at all left after 20 -30 hrs or so.. Just my 2 cts....

[kostas74]

I will check the plug again.
I think the electrode is not eaten , on the photo what you see is carbon built up.

[XstreamVking]

Have you been running the merc engine cleaner with the fuel? Optis need to have the cleaner run thu them every few hundred gallons. Mine run noticeably better after the cleaner is used. If one plug is really different from the others something is outta whack....My plugs usually look kinda sooty and tan, with a white tip on the electrode. And all look the same. Mine are 225s, but should be the same plug. Is the motor running good?

[kostas74]

I also use cleaner regularly (quickclean) .
The rest plugs look half tan but #6 is white all around.
The engine runs ok but some time ago i had my ECU recalibrated and my flywheel lightened but i didn't see any difference .
Maybe is something wrong and i didn't realized it.

[XstreamVking]

You might contact the people that reflashed your ecu and ask what they think may be happening..... I'm just a shade tree mechanic in training. But that plug looks hot to me.

[kostas74]

Yes it looks hot to me too.
The man who reflashed my ECU (not in the USA) when i told him i didn't see any difference he insisted that i had to try different props.
I did that but nothing changed.

[kostas74]

Gone today for a ride with my boat and i checked the #6 cylinder's spark plug and it looked exactly the same as in the photo.
I think that cylinder is running too hot .
Is there a chance that the cylinder is not running hot and still get this white looking plug?

[XstreamVking]

I would get the air and fuel injectors checked on that cylinder if it was mine. If a merc. tech sees this thread, maybe he will have a clue as to what is going on... My fear would be that the white stuff is alum. particles.....

[kostas74]

The white stuff is carbon pieces, they look like metal pieces because the camera's flash hit on them don't worry.
I changed the #6 spark plug today with an older one and went for a ride. When i got back home i checked this plug and from black and brown color it became white as the one in the photo.
After that i changed place of the #6 and #5 coils and i will check the engine again in a couple of days.
Thank you for replying!

[XstreamVking]

Those coils will do some strange things..... Let us know the change if any.....

[kostas74]

I'll do that

[kostas74]

I tested today my boat again and sadly i didn't see any change from the coil swap .
The #6 spark plug is still white color.
I am starting to think that #6 cylinder is working lean.
Is there a chance that the reflush of the ECU went wrong?
I also tested the resistance of both the fuel and the direct injectors and they seem ok at least electrically.
Please help i don't know what to do next.

[kostas74]

Nobody?