2 wet plugs, 4 dry ??

[VinceJE]

1996 Merc 225 EFI, No history of any problems, Runs like a champ, but...

I noticed something weird the other day when I took the plugs out for annual replacement... I had idled it on the earmuffs for a few minutes before I pulled the plugs. I noticed 2 of the 6 were wet with oil and the other 4 were not.

The 2 wet ones were in the bottom 2 right hand cylinders (looking at the back of the motor).

I found this to be odd, but maybe it's not. I just never noticed it before. It runs great, but this is bugging me.

Any ideas?... THANKS!!

 

[CharlieB]

Re: 2 wet plugs, 4 dry ??

When in doubt, check it out.

It never hurts to run a compression test and a spark test as an annual systems check to keep up with the health of your motor.

Write down the #'s somewhere so you can be sure to see any change from year to year.

If everything checks out fine then you may lean towards possible mineral accumulation on the injector tips, fouling the fine spray pattern and irregular fuel/air burn, leading to carbon deposits and/or wetting of a spark plug.

A regular fuel treatment with fuel system cleaner such as Chevron Techtron or Seafoam, is always a good idea.

 

[hdodt]

Re: 2 wet plugs, 4 dry ??

I am by no means an expert on your motor, but if the ignition was killed just before those two cylinders hit the intake stroke, but hadnt fired, could that leave them wet while the others may have been fired thus dried? Simple test would be to put the plugs back in, start the motor, then remove them and see if they are wet again. Maybe?